Library Management System. This software is designed & developed by sajib.U use it , follow below link....
Library Management System.
Monday, 30 April 2012
Library Management System
Library Management System. This software is designed & developed by sajib.U use it , follow below link....
Library Management System.
Thursday, 19 April 2012
Networking Command
Ping
For WindowsSyntax
ping localhost
ping
google.com
Ping the host google.com to see if it is alive.
ping google.com -c 1
Ping the host google.com once and return to the command line as shown below.
PING google.com (204.228.150.3) 56(84) bytes of data.
64 bytes from www.google.com (204.228.150.3): icmp_seq=1 ttl=63 time=0.267 ms
--- google.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.267/0.267/0.267/0.000 ms
Windows 95, 98, and ME syntax
The default is to display only the IP address, subnet mask and default gateway for each adapter bound to TCP/IP.
For Release and Renew, if no adapter name is specified, then the IP address leases for all adapters bound to TCP/IP will be released or renewed.
For SetClassID, if no class id is specified, then the classid is removed.
To get your computers local network IP address, subnet mask, and default gateway typing ipconfig alone will display this information as shown below. Keep in mind this is only your local network information. If you're trying to determine your IP address used on the Internet we suggest viewing our system information page.
ipconfig
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . : hsd1.ut.comcast.net.
IP Address. . . . . . . . . . . . : 192.168.201.245
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.201.1
To get all local network information for your computer use the /all switch as shown below, followed by the results that would be seen when using this command.
ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . : COMPUTERH1
DNS Servers . . . . . . . . : 123.45.67.8
111.111.111.1
111.111.111.1
Node Type . . . . . . . . . : Broadcast
NetBIOS Scope ID. . . . . . :
IP Routing Enabled. . . . . : No
WINS Proxy Enabled. . . . . : No
NetBIOS Resolution Uses DNS : No
0 Ethernet adapter :
Description . . . . . . . . : PPP Adapter.
Physical Address. . . . . . : 44-44-44-54-00-00
DHCP Enabled. . . . . . . . : Yes
IP Address. . . . . . . . . : 123.45.67.802
Subnet Mask . . . . . . . . : 255.255.0.0
Default Gateway . . . . . . : 123.45.67.801
DHCP Server . . . . . . . . : 255.255.255.255
Primary WINS Server . . . . :
Secondary WINS Server . . . :
Lease Obtained. . . . . . . : 01 01 80 12:00:00 AM
Lease Expires . . . . . . . : 01 01 80 12:00:00 AM
1 Ethernet adapter :
Description . . . . . . . . : 3Com 3C90x Ethernet Adapter
Physical Address. . . . . . : 00-50-04-62-F7-23
DHCP Enabled. . . . . . . . : Yes
IP Address. . . . . . . . . : 111.111.111.108
Subnet Mask . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . : 111.111.111.1
DHCP Server . . . . . . . . : 111.111.111.1
Primary WINS Server . . . . :
Secondary WINS Server . . . :
Lease Obtained. . . . . . . : 11 16 00 12:12:44 AM
Lease Expires . . . . . . . :
Reference: http://www.computerhope.com/ipconfig.htm
Hostname
About hostname
Display the hostname of the machine the command is being run on. Additional information about the term hostname can be found on our hostname dictionary definition.
The hostname command is an external command and is available in the below Microsoft operating systems.
Windows 2000
Windows XP
Windows Vista
Windows 7
hostname
sethostname: Use the Network Control Panel Applet to set hostname.
hostname -s is not supported.
hostname
Users with Microsoft Windows 2000 and Windows XP who need additional information network latency and network loss should also consider using the pathping command.
The tracert.exe command is an external command that is available in the below Microsoft operating systems.
MS-DOS 6.2
Windows 95
Windows 98
Windows ME
Windows NT
Windows 2000
Windows XP
Windows Vista
Windows 7
Options:
Below is an example when we used tracert on www.computerhope.com.
As you can see in the below example, we had a very short list and time
to get to its destination because of the location we are.
tracert computerhope.com
traceroute computerhope.com - would display results similar to the
below example.
traceroute to computerhope.com (166.70.10.23), 30 hops max, 40 byte packets
1 198.60.22.1 (198.60.22.1) 2.303 ms 1.424 ms 2.346 ms
2 krunk3.xmission.com (198.60.22.6) 0.742 ms * 1.521 ms
For WindowsSyntax
| ping | [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS] |
| [-r count] [-s count] [[-j host-list] | [-k host-list]] | |
| [-w timeout] destination-list |
| Options: | |
| -t | Pings the specified host until stopped. To see statistics and continue - type Control-Break; To stop - press Ctrl +C |
| -a | Resolve addresses to hostnames. |
| -n count | Number of echo requests to send. |
| -l size | Send buffer size. |
| -f | Set Don't Fragment flag in packet. |
| -i TTL | Time To Live. |
| -v TOS | Type Of Service. |
| -r count | Record route for count hops. |
| -s count | Timestamp for count hops. |
| -j host-list | Loose source route along host-list. |
| -k host-list | Strict source route along host-list. |
| -w timeout | Timeout in milliseconds to wait for each reply. |
Pings
the local host, this will allow you to see if the computer is able to
send information out and receive the information back. Note that this
does not send information over a network but may allow you to see if the
card is being seen.
ping xxx.xxx.xxx.xxx
Allows you to ping another computer where the x's
are located are where you would place the IP address of the computer
you are attempting to ping. If this is not able to complete, this should
relay back an unsuccessful message, which could be an indication of
cable issues, network card issues, hub issue, etc.
ping computerhope.com
PING computerhope.com (204.228.150.3) 56(84) bytes of data.
64 bytes from www.computerhope.com (204.228.150.3): icmp_seq=1 ttl=63 time=0.267 ms
--- computerhope.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.267/0.267/0.267/0.000 ms
64 bytes from www.computerhope.com (204.228.150.3): icmp_seq=1 ttl=63 time=0.267 ms
--- computerhope.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.267/0.267/0.267/0.000 ms
For Linux
Syntax
ping -s [-d] [-l] [-L] [-n] [-r] [-R] [-v] [ -i interface_address ] [-I interval] [-t ttl] host [packetsize] [count]| -d | Set the SO_DEBUG socket option. |
| -l | Loose source route. Use this option in the IP header to send the packet to the given host and back again. Usually specified with the -R option. |
| -L | Turn off loopback of multicast packets. Normally, if there are members in the host group on the out- going interface, a copy of the multicast packets will be delivered to the local machine. |
| -n | Show network addresses as numbers. ping normally displays addresses as host names. |
| -r | Bypass the normal routing tables and send directly to a host on an attached network. If the host is not on a directly-attached network, an error is returned. This option can be used to ping a local host through an interface that has been dropped by the router daemon. |
| -R | Record route. Sets the IP record route option, which will store the route of the packet inside the IP header. The contents of the record route will only be printed if the -v option is given, and only be set on return packets if the target host preserves the record route option across echos, or the -l option is given. |
| -v | Verbose output. List any ICMP packets, other than ECHO_RESPONSE, that are received. |
| -i interface_address | Specify the outgoing interface address to use for multicast packets. The default interface address for multicast packets is determined from the (unicast) routing tables. |
| -I interval | Specify the interval between successive transmissions. The default is one second. |
| -t ttl | Specify the IP time to live for unicast and multicast packets. The default time to live for unicast packets is set with ndd (using the icmp_def_ttl variable). The default time to live for multicast is one hop. |
| host | The network host. |
| packetsize | Specified size of packetsize. Default is 64. |
| count | Amount of times to send the ping request. |
Ping the host google.com to see if it is alive.
ping google.com -c 1
Ping the host google.com once and return to the command line as shown below.
PING google.com (204.228.150.3) 56(84) bytes of data.
64 bytes from www.google.com (204.228.150.3): icmp_seq=1 ttl=63 time=0.267 ms
--- google.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.267/0.267/0.267/0.000 ms
Reference : http://www.computerhope.com/issues/ch000444.htm#02
ipconfig
Ipconfig is a DOS utility that can be used from MS-DOS
and a MS-DOS shell to display the network settings currently assigned
and given by a network. This command can be utilized to verify a network
connection as well as to verify your network settings.
Windows 95, 98, and ME syntax
| /All | Display detailed information. |
| /Batch [file] | Write to file or ./WINIPCFG.OUT |
| /renew_all | Renew all adapters. |
| /release_all | Release all adapters. |
| /renew N | Renew adapter N. |
| /release N | Release adapter N. |
Windows 2000 and XP syntax
ipconfig
[/? | /all | /release [adapter] | /renew [adapter] | /flushdns |
/registerdns | /showclassid adapter | /setclassid adapter [classidtoset]
]| /all | Display full configuration information. |
| /release | Release the IP address for the specified adapter. |
| /renew | Renew the IP address for the specified adapter. |
| /flushdns | Purges the DNS Resolver cache. |
| /registerdns | Refreshes all DHCP leases and re-registers DNS names |
| /displaydns | Display the contents of the DNS Resolver Cache. |
| /showclassid | Displays all the dhcp class IDs allowed for adapter. |
| /setclassid | Modifies the dhcp class id. |
For Release and Renew, if no adapter name is specified, then the IP address leases for all adapters bound to TCP/IP will be released or renewed.
For SetClassID, if no class id is specified, then the classid is removed.
To get your computers local network IP address, subnet mask, and default gateway typing ipconfig alone will display this information as shown below. Keep in mind this is only your local network information. If you're trying to determine your IP address used on the Internet we suggest viewing our system information page.
ipconfig
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . : hsd1.ut.comcast.net.
IP Address. . . . . . . . . . . . : 192.168.201.245
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.201.1
To get all local network information for your computer use the /all switch as shown below, followed by the results that would be seen when using this command.
ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . : COMPUTERH1
DNS Servers . . . . . . . . : 123.45.67.8
111.111.111.1
111.111.111.1
Node Type . . . . . . . . . : Broadcast
NetBIOS Scope ID. . . . . . :
IP Routing Enabled. . . . . : No
WINS Proxy Enabled. . . . . : No
NetBIOS Resolution Uses DNS : No
0 Ethernet adapter :
Description . . . . . . . . : PPP Adapter.
Physical Address. . . . . . : 44-44-44-54-00-00
DHCP Enabled. . . . . . . . : Yes
IP Address. . . . . . . . . : 123.45.67.802
Subnet Mask . . . . . . . . : 255.255.0.0
Default Gateway . . . . . . : 123.45.67.801
DHCP Server . . . . . . . . : 255.255.255.255
Primary WINS Server . . . . :
Secondary WINS Server . . . :
Lease Obtained. . . . . . . : 01 01 80 12:00:00 AM
Lease Expires . . . . . . . : 01 01 80 12:00:00 AM
1 Ethernet adapter :
Description . . . . . . . . : 3Com 3C90x Ethernet Adapter
Physical Address. . . . . . : 00-50-04-62-F7-23
DHCP Enabled. . . . . . . . : Yes
IP Address. . . . . . . . . : 111.111.111.108
Subnet Mask . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . : 111.111.111.1
DHCP Server . . . . . . . . : 111.111.111.1
Primary WINS Server . . . . :
Secondary WINS Server . . . :
Lease Obtained. . . . . . . : 11 16 00 12:12:44 AM
Lease Expires . . . . . . . :
Reference: http://www.computerhope.com/ipconfig.htm
Hostname
About hostname
Display the hostname of the machine the command is being run on. Additional information about the term hostname can be found on our hostname dictionary definition.
The hostname command is an external command and is available in the below Microsoft operating systems.
Windows 2000
Windows XP
Windows Vista
Windows 7
hostname
sethostname: Use the Network Control Panel Applet to set hostname.
hostname -s is not supported.
hostname
Running the command would display the hostname for the computer.
TRACERT and TRACEROUTE
For Windows
About tracert
The
tracert command is used to visually see a network packet being sent and
received and the amount of hops required for that packet to get to its
destination.Users with Microsoft Windows 2000 and Windows XP who need additional information network latency and network loss should also consider using the pathping command.
The tracert.exe command is an external command that is available in the below Microsoft operating systems.
MS-DOS 6.2
Windows 95
Windows 98
Windows ME
Windows NT
Windows 2000
Windows XP
Windows Vista
Windows 7
| tracert | [-d] [-h maximum_hops] [-j host-list] [-w timeout] target_name |
| -d | Do not resolve addresses to hostnames. |
| -h maximum_hops | Maximum number of hops to search for target. |
| -j host-list | Loose source route along host-list. |
| -w timeout | Wait timeout milliseconds for each reply. |
tracert computerhope.com
| 1 | 169 ms | 190 ms | 160 ms | slc1-tc.xmission.com [166.70.1.20] | |||||
| 2 | 159 ms | 160 ms | 190 ms | cisco0-tc.xmission.com [166.70.1.1] | |||||
| 3 | 165 ms | 189 ms | 159 ms | www.computerhope.com [166.70.10.23] |
For Linux
Print the route packets take to network host.
traceroute
[-d] [-F] [-I] [-n] [-v] [-x] [-f first_ttl] [-g gateway [-g gateway] |
-r] [-i iface] [-m max_ttl] [-p port] [-q nqueries] [-s src_addr] [-t
tos] [-w waittime ] host [packetlen]| -d | Set the SO_DEBUG socket option. |
| -F | Set the "don't fragment" bit. |
| -I | Use ICMP ECHO instead of UDP datagrams. |
| -n | Print hop addresses numerically rather than symbolically and numerically. This saves a nameserver address-to-name lookup for each gateway found on the path. |
| -v | Verbose output. For each hop, the size and the destination of the response packets is displayed. Also ICMP packets received other than TIME_EXCEEDED and UNREACHABLE are listed as well. |
| -x | Prevent traceroute from calculating checksums. Note that checksums are usually required for the last hop when using ICMP ECHO probes. See the -I option. |
| -f first_ttl | Set the starting ttl value to first_ttl, to override the default value 1. traceroute skips processing for those intermediate gateways which are less than first_ttl hops away. |
| -g gateway | Specify a loose source route gateway. The user can specify more than one gateway by using -g for each gateway. The maximum that can be set is 8. |
| -r | Bypass the normal routing tables and send directly to a host on an attached network. If the host is not on a directly-attached network, an error is returned. This option can be used to send probes to a local host through an interface that has been dropped by the router daemon. |
| -i iface | Specify a network interface to obtain the source IP address for outgoing probe packets. This is normally only useful on a multi-homed host. The -s option is also another way to do this. Note that this option does not provide a way to specify the interface on which the probe packets are sent. |
| -m max_ttl | Set the maximum ttl used in outgoing probe packets. The default is 30 hops, which is the same default used for TCP connections. |
| -p port | Set the base UDP port number used in probes. The default is 33434. traceroute hopes that nothing is listening on UDP ports (base+(nhops- 1)*nqueries) to (base+(nhops*nqueries)-1)at the destination host, so that an ICMP PORT_UNREACHABLE message will be returned to terminate the route tracing. If something is listening on a port in the default range, this option can be used to select an unused port range.nhops is defined as the number of hops between the source and the destination. |
| -q nqueries | Set the desired number of probe queries. The default is 3. |
| -s src_addr | Use the following address, which usually is given as an IP address, not a hostname, as the source address in outgoing probe packets. On multi-homed hosts, those with more than one IP address, this option can be used to force the source address to be something other than the IP address traceroute picks by default. If the IP address is not one of this machine's interface addresses, an error is returned and nothing is sent. When used together with the -i option, the given IP address should be configured on the specified interface. Otherwise, an error will be returned. |
| -t tos | Set the tos(type-of-service) in probe packets to the specified value. The default is zero. The value must be an integer in the range from 0 to 255. Gateways along the path may route the probe packet differently depending upon the tos value set in the probe packet. |
| -w waittime | Set the time, in seconds, to wait for a response to a probe. The default is five (5) seconds. |
| host | The network host. |
traceroute to computerhope.com (166.70.10.23), 30 hops max, 40 byte packets
1 198.60.22.1 (198.60.22.1) 2.303 ms 1.424 ms 2.346 ms
2 krunk3.xmission.com (198.60.22.6) 0.742 ms * 1.521 ms
Note:
in this example because we are local to the address we are tracerouting
the amount of hops is very minimal. However, when you traceroute
computerhope.com you may hop more than we do.
This command is very useful for distinguishing
network or
router issues. If the domain does not work or is not available you can traceroute an IP.Monday, 16 April 2012
Monday, 9 April 2012
নেটওয়ার্ক ম্যানেজমেন্টের টুল
নেটওয়ার্ক ম্যানেজমেন্টের টুল
সব নেটওয়ার্ক ম্যানেজারকে একসেট কৌশলী টুল রাখতে হয়, যা প্রতিদিনের কাজগুলো যেমন নেটওয়ার্ক মনিটরিং ও ম্যানেজমেন্ট, হার্ডওয়্যার ট্রাবলশূটিং ও ইনভেন্টরি ইত্যাদি পারফর্ম করতে পারে৷ এবার নেটওয়ার্ক বিভাগে এ ধরনের প্রয়োজনীয় কিছু টুল নিয়ে আলোচনা করা হয়েছে৷
কিছু কিছু বিষয় রয়েছে, যেগুলো নেটওয়ার্ক ম্যানেজিংয়ের ক্ষেত্রে অবহেলা করা উচিত নয়৷ যেমন- সিকিউরিটি, সফটওয়্যার বা হার্ডওয়্যার ফেইল্যুর এবং ইনভেন্টরির পরিবর্তন৷ উপরোল্লিখিত বিষয়গুলো যথাযথভাবে ম্যানেজ করার জন্য দরকার একসেট টুল৷ ভালো মানের কার্যকর একসেট টুল দিয়ে নেটওয়ার্ক ম্যানেজার তার নেটওয়ার্ক সিস্টেমকে অত্যন্ত কার্যকর হিসেবে প্রতিষ্ঠা করতে পারেন৷ এসব টুল নেটওয়ার্ক ম্যানেজারকে বিভিন্ন ঝামেলা থেকে রক্ষা করতে পারবে৷ এই টুলগুলো যথাযথভাবে ব্যবহার করে নেটওয়ার্ক ম্যানেজার তাদের সিস্টেমের ব্যাপারে নিশ্চিন্ত থাকতে পারেন৷
নেটওয়ার্ক মনিটরিং
অজানা কারণে হার্ডওয়্যার/সফটওয়্যার ফেইল্যুরের মুখোমুখি হবেন না, এমনটি নিশ্চিত হতে পারবেন নিয়মিতভাবে সেগুলো মনিটর করে এবং এর কার্যকারিতা স্থবির হবার আগে ত্রুটিপূর্ণ মেশিনারিগুলোকে সংশোধন বা প্রতিস্থাপন করার মাধ্যমে৷ এছাড়া আপনার নেটওয়ার্কের ব্যবহারকারী ও তাদের কার্যকলাপও ট্র্যাক করতে হবে৷ নিচে বর্ণিত টুল দুটি আপনাকে একাজে সহায়তা করতে পারবে৷
এনটপ :
ইন্টারনেট গেটওয়ের মাধ্যমে যে ডাটা প্রবাহ হয়, সেগুলো এই টুল ক্যাপচার করে এবং তা উপস্থাপন করে খুবই সমন্বিত গ্রাফ ও চার্টে৷ এনটপ টুল দিয়ে মনিটর করতে পারবেন সর্বমোট ব্যবহার হওয়া ব্যান্ডউইডথ, প্রোটকল লেভেল এবং ইউজার লেভেলে ব্যবহার হওয়া ব্যান্ডউইডথ৷ এনটপ ব্যবহার করা যেতে পারে উইন্ডোজ বা লিনআক্সে৷ তবে মনে রাখতে হবে, সবচেয়ে ভালো ফলাফল পেতে হলে গেটওয়েতে এনটপ ইনস্টল করতে হবে৷ গেটওয়ে যেই অপারেটিং সিস্টেমেই রান করুক না কেন এনটপ ভার্সন যেনো হয়, তা খেয়াল রাখতে হবে৷
চিত্র-১ : এনটপ নেটওয়ার্ক সিস্টেমের ডিটেইল ভিউ
এনটপের ইনস্টলেশন প্রক্রিয়াটি খুবই সহজ৷ উইন্ডোজ ভার্সনে ইনস্টলার রান করে কয়েকবার নেক্সট-এ ক্লিক করলেই হবে৷ সিস্টেম ইনস্টল হবার পরপরই ক্লক সিস্টেম বার-এর পাশে NTop xtra -এর আইকন দেখা যাবে৷ এই আইকনে ডবল ক্লিক করলে একটি উইন্ডো খুলবে৷
এবার Start NTop Service -এ ক্লিক করে এনটপ অপশন রান করুন৷ এর ফলে http://localhost:3000 অ্যাড্রেসসহ একটি আইই উইন্ডো ওপেন হবে৷ এটি হচ্ছে সেই লোকেশন যেখান থেকে ভবিষ্যতে এনটপ পেজে এক্সেস করা যাবে৷ এ সিস্টেমটি অত্যন্ত স্বব্যাখ্যামূলক এবং কোনোরকম ঝামেলা ছাড়াই ব্যবহার করা যাবে৷ এটি ফ্রি ডাউনলোড করা যাবে http://openextra.co.uk সাইট থেকে৷
ওপেনএনএমএস :
ওপেনএনএমএস হচ্ছে একটি ওপেন সোর্স নেটওয়ার্ক ম্যানেজমেন্ট সিস্টেম, যা যেকোনো অপারেটিং সিস্টেমে রান করে৷ এটি জাভা ও টমক্যাট সাপোর্ট করে৷ এই সফটওয়্যারটি এসএনএমপি (SNMP) সার্ভিস জরিপ, ডাটা সংগ্রহ, বিজ্ঞপ্তি প্রদান এবং ইভেন্ট ম্যানেজমেন্ট করতে পারে৷
চিত্র-২ : ওপেনএনএমএস প্রদর্শিত সার্ভিসের স্ট্যাটাস
এই সফটওয়্যার ব্যবহার করে গুরুত্বপূর্ণ সার্ভার এবং স্বতন্ত্র সার্ভিসকে মনিটর করতে পারবেন যেগুলো এইচটিটিপি, এফটিপি, মাইএসকিউএলে রান করে৷
ওপেনএনএমএসের ইনস্টলেশন প্রক্রিয়া কিছুটা বিরক্তিকর এবং আপনাকে কয়েকটি কম্পোনেন্ট যেমন জাভা ও টমক্যাট কনফিগার করতে হবে কাজ করার জন্য৷ এটি ফ্রি ডাউনলোড করা যাবে http://openNMS.org সাইট থেকে৷
হার্ডওয়্যার ইনভেন্টরি
নেটওয়ার্ক মনিটরিং ছাড়া নেটওয়ার্ক ম্যানেজমেন্ট টুলের পরবর্তী গুরুত্বপূর্ণ বিষয় হলো আপনার মালিকানাধীন সম্পদকে মনিটর করা৷ যেকোনো প্রতিষ্ঠানের জন্য হার্ডওয়্যার/সফটওয়্যার এবং তাদের পরিবর্তনকে ট্র্যাক করা অত্যন্ত গুরুত্বপূর্ণ৷ এর ফলে গুরুত্বপূর্ণ ডাটা অনাকাঙিক্ষত ব্যক্তিদের হাত থেকে রক্ষা পাবে, শুধু তাই নয় রিসোর্সের অপব্যবহারকেও দমন করা যাবে৷ এটি ত্রুটিপূর্ণ ইক্যুইপমেন্টকে ট্র্যাক করে এবং ক্ষেত্রবিশেষ সতর্কও করে ফেইল্যুরের আগে৷
নিচে বর্ণিত টুলগুলো দিয়ে এ কাজগুলো সহজেই করা যায় :
সিসএইড :
এটি একটি পরিপূর্ণ অ্যাসেট ম্যানেজমেন্ট এবং আইটি হেল্প ডেস্ক ম্যানেজমেন্ট সফটওয়্যার৷ এই সফটওয়্যার ও সহযোগী এজেন্ট দিয়ে আপনার নেটওয়ার্কের সব রানিং মেশিনের হার্ডওয়্যার ও সফটওয়্যার কম্পোনেন্টকে ট্র্যাক করা যাবে৷
চিত্র-৩ : সিসএইড দিয়ে এরর সাবমিট করা
এই অ্যাপ্লিকেশনের বাড়তি সুবিধা হলো এটিকে হেল্প ডেস্ক সিস্টেম হিসেবে ব্যবহার করা যায়৷ সিসএইড সফটওয়্যারের ইনস্টলেশন প্রক্রিয়া খুব সহজ এবং ব্যবহারকারীরা তাদের অভিযোগ সরাসরি একই এজেন্টে উইজার্ড ম্যানেজারে জানাতে পারেন৷ সিসএইড সার্ভারের ইনস্টলেশন প্রক্রিয়াটি খুব সহজ৷ এজন্য ইনস্টলার স্টার্ট করে উইজার্ড অনুসরণ করুন৷ এখানে আপনাকে একমাত্র ভ্যালু উইজার্ডে দিতে হবে৷ আর তা হচ্ছে মেইল সার্ভার এবং অ্যাড্রেস ও পোর্টে রিপ্লাই করতে হবে, যা সিসএইড পোর্টালে এক্সেসযোগ্য হবে৷
এজেন্ট ইনস্টলেশন প্রক্রিয়াও সহজ৷ এজন্য সার্ভার মেশিনে ম্যানুয়ালভাবে এজেন্ট সেটআপ ফাইল ইনস্টল করতে হবে৷ এখানে আপনার কাছে কেবল সার্ভারের আইপি অ্যাড্রেস এবং এজেন্ট ইনস্টলেশন ফাইলের সিরিয়াল নম্বর জানতে চাইবে৷ যদি আপনি ফ্রি ভার্সন সফটওয়্যার ব্যবহার করেন, তাহলে সিরিয়াল নম্বরও ফ্রি পাবেন৷ তবে এই সেটআপ শুধু ১০০ ব্যবহারকারীর জন্য প্রযোজ্য হবে বা তিন অ্যাডমিনিস্ট্রেটরের জন্য প্রযোজ্য৷ এটি ফ্রি ডাউনলোড করা যাবে http://ilient.com সাইট থেকে৷
আলকেমি আই :
এই অ্যাপ্লিকেশনটি সার্ভার ও হার্ডওয়্যার কম্পোনেন্টের পর্যাপ্ততার প্রতি লক্ষ রাখে৷ যদি কোনো কারণে ফেইল্যুর হয় বা হার্ডওয়্যার কম্পোনেন্টের পরিবর্তন করা হয়, তখন এটি তাত্ক্ষণিকভাবে ই-মেইলের মাধ্যমে অ্যাডমিনিস্ট্রেটরের কাছে সতর্ক বার্তা পাঠিয়ে বা এসএমএস করে৷
উইজার্ড অনুসরণ করে খুব সহজেই আলকেমি আই ইনস্টল করা যায়৷ ইনস্টলেশনের পর অ্যাপ্লিকেশন রান করুন৷ এজন্য ফাইল মেনুতে গিয়ে Scan Network অপশনে ক্লিক করুন৷ স্ক্যান নেটওয়ার্ক উইজার্ড আবির্ভূত হবার পর যে মেশিন শনাক্ত করতে চান তার আইপি রেঞ্জ দিন৷
আইপি রেঞ্জ দেয়ার পর সার্ভিস সিলেক্ট করুন, যার জন্য স্ক্যান করতে চান৷ Start বাটনে ক্লিক করে সার্চ প্রসেস শুরু করুন৷ নেটওয়ার্কে কয়টি মেশিন রয়েছে, তার ওপর ভিত্তি করে কিছু সময় লাগবে এর জন্য৷ স্ক্যান সম্পন্ন হবার পর নেটওয়ার্কের সব সচল মেশিনের লিস্ট প্রদর্শিত হবে৷ ওএসসহ রানিং সার্ভিসের লিস্টও প্রদর্শন করবে৷ এরপর কাঙিক্ষত সার্ভিসের জন্য মেশিনে নজরদারিও সেট করতে পারেন৷ ICMP-ping বাইডিফল্ট সব মেশিনের জন্য এনাবল থাকে৷ এ কাজটি সম্পন্ন করার পর ওকে করলে মেইন উইন্ডো আবির্ভূত হবে৷ এর ফলে মেইন উইন্ডো থেকে মেশিনের স্ট্যাটাস দেখতে পারবেন এবং লক্ষ রাখতে পারবেন সার্ভিসের প্রতি৷ ওয়েবসাইট : http:/ www.alchemy-lab.com/products/eye ৷
নেটওয়ার্ক ম্যানেজমেন্ট
মনিটরিং গুরুত্বপূর্ণ, তবে তথ্য মনিটরিংয়ের পর কি করবেন বা যদি কোনো এরর থাকে তাহলে কী কী উচিত, এ বিষয়টি যথেষ্ট গুরুত্বপূর্ণ৷ সুতরাং পরবর্তী ধাপটি হচ্ছে এসব তথ্যকে ভালোভাবে ম্যানেজ করা এবং ত্রুটিপূর্ণ ডিভাইসকে ম্যানেজ করা৷
নিচে বর্ণিত সফটওয়্যারটি এব্যাপারে সহায়তা করতে পারে :
ল্যান সার্ভেয়র :
এটি আপনার নেটওয়ার্ক ম্যাপিংয়ের জন্য একটি চমত্কার ফিচারসমৃদ্ধ অ্যাপ্লিকেশন৷ এর ৩০ দিনের ট্রায়াল ভার্সন ফ্রি পাওয়া যাবে http://neon.com সাইট থেকে৷
চিত্র-৪ : ল্যান সার্ভেয়রে তৈরি করা নেটওয়ার্ক ম্যাপ
এর ইনস্টলেশন প্রক্রিয়াটি খুব সহজ৷ উইজার্ড অনুসরণ করে কয়েক মিনিটের মধ্যেই ইনস্টল করতে পারবেন৷ ইনস্টলেশনের পর এটি একটি উইজার্ড স্টার্ট করবে৷
এখানে আপনাকে নেটওয়ার্ক সাবনেটের বিস্তারিত তথ্য দিতে হবে৷ উদাহরণস্বরূপ বলা যায়, আপনি ক্লাস C নেটওয়ার্ক 192.168.0.X ব্যবহার করছেন৷ সুতরাং আপনি 192.168.0.1 থেকে 192.168.0.254-এর মধ্যে সব মেশিনে সার্চ করতে চাইতে পারেন৷ সিস্টেমে এই ভ্যালু প্রদান করুন এবং LANSurveyor -এ আপনার কাঙিক্ষত নম্বরটি উল্লেখ করুন যেটি আপনি সার্চ করতে চাচ্ছেন৷
এই পেজের নিচে উল্লেখ করতে পারেন, আপনার নেটওয়ার্কের কোন ধরনের নোড খুঁজে পেতে চান৷ যেমন ICPM রেসপন নোড, নেটবায়োস ক্লায়েন্ট, SIP ক্লায়েন্ট ইত্যাদি৷
এরপর Ok -তে ক্লিক করলে সার্চ প্রসেস শুরু হবে৷ নেটওয়ার্কের সাইজের ওপর নির্ভর করে এবং সাবনেট ক্লাসের ওপর ভিত্তি করে সার্চ কার্যক্রম শুরু হবে, যা কয়েক মিনিট থেকে শুরু করে কয়েক ঘণ্টার মধ্যে সম্পন্ন হবে৷ সার্চ সম্পন্ন হলে এটি লিঙ্ক কানেকশনসহ আপনার নেটওয়ার্কের ম্যাপসহ উপস্থিত হবে৷ এই ম্যাপে সিলেক্ট করতে পারবেন এবং যেকোনো মেশিনের ত্রুটির জন্য বা লিঙ্ক রেসপন্সের জন্য সতর্কতা সৃষ্টি করতে পারবেন৷ এমনকি নিয়ন এজেন্টকে তাদের ওয়েবসাইট থেকে কিনতে বা ডাউনলোড করতে পারবেন৷
Sunday, 1 April 2012
Supernetting
Supernetting, also called Classless Inter-Domain Routing (CIDR), is a way to aggregate multiple Internet addresses of the same class. The original Internet Protocol (IP) defines IP addresses in four major classes of address structure, Classes A through D. Each class allocates one portion of the 32-bit Internet address format to a network address and the remaining portion to the specific host machines
Learn More
Network Design
Networking Resources
within the network. Using supernetting, the network address 192.168.2.0/24 and an adjacent address 192.168.3.0/24 can be merged into 192.168.2.0/23. The "23" at the end of the address says that the first 23 bits are the network part of the address, leaving the remaining nine bits for specific host addresses. Supernetting is most often used to combine Class C network addresses and is the basis for most routing protocols currently used on the Internet.
Supernetting was created as a way to solve the problem of routing tables growing beyond the ability of current software and people to manage and to provide a solution to the exhaustion of Class B network address space. Supernetting allows one routing table entry to represent an aggregation of networks much like one area code represents an aggregation of telephone numbers in an area.
Learn More
Network Design
Networking Resources
within the network. Using supernetting, the network address 192.168.2.0/24 and an adjacent address 192.168.3.0/24 can be merged into 192.168.2.0/23. The "23" at the end of the address says that the first 23 bits are the network part of the address, leaving the remaining nine bits for specific host addresses. Supernetting is most often used to combine Class C network addresses and is the basis for most routing protocols currently used on the Internet.
Supernetting was created as a way to solve the problem of routing tables growing beyond the ability of current software and people to manage and to provide a solution to the exhaustion of Class B network address space. Supernetting allows one routing table entry to represent an aggregation of networks much like one area code represents an aggregation of telephone numbers in an area.
How to login block website
Details for UltraSurf
Download UltraSurf
What is Tor?
Tor is free software and an open network that helps you defend against a form of network surveillance that threatens personal freedom and privacy, confidential business activities and relationships, and state security known as traffic analysis.
Details for Tor
Download Tor
Friday, 9 March 2012
Members List of ISP
Members List of ISPAB (in Alphabetical order)
Aamra Networks Limited.
Sharful Alam
Cheif Operating Officer
Faruq Rupayan Tower (20th Floor)
32, Kemal Ataturk Avenue
Banani, C/A, Dhaka-1213
E-mail- sharful.alam@aamra.com.bd
Cell- 01713000258
Phone- 8861100
Fax- 8860077
Access Telecom (BD) Ltd.
Zain Omar
Suite-901, Concord Tower
113, Kazi Nazrul Islam Avenue, Dhaka
Phone: 9335607-10
Email: zainomar@accesstel.net
Advanced Data Networks System Ltd.
Red Crescent Concord Tower (19th Floor)
17, Mohakhali Commercial Area
Dhaka - 1212, Bangladesh.
Phone: +(880 2) 886 1234 - 8
Fax: +(880 2) 988 7551
Website: http://www.adnsl.net
Email: info@adnsl.net
Aftab IT Ltd.
Akhtaruzzaman Manju
Eastern Trade Center (14th floor)
56 Inner circular Road, Dhaka
Phone: 9352356, 0171527523
Email: manju@aitlbd.net
Agni Systems Ltd
Md. A. Salam
Navana Tower, (11th floor)
Suite-A, 45, Gulshan-1, Dhaka-
Phone: 8812379
Email: info@agni.com
Akceycom Limited
Dinesh Dissanayake
Uday Tower (9th Floor)
Plot#57 & 57/A
Gulshan -1, Dhaka-1212
Phone- 88 02 9861681
Fax- 88 02 9862159
E-mail- info@aknetbd.com
Akij Online Ltd
SK. Aminuddin
Akij Chamber, 73-Dilkusha, Dhaka
Phone: 9571278-80
Email: info@akijonline.com
Always On Network Bangladesh Ltd
Ameer Ali
Chief Coordinating Officer
House- CWN CB) -6, Road – 36,
Gulshan -2, Dhaka-1212
Phone: 8850643-4, 01611410323
Email: ispab@aonbd.net
Asia Pacific Communication
Sk. Abdur Rahim
Keari Plaza (4th floor)
83, Satmasjid Road,Dhanmondi 8/A
Dhaka-1209
Phone-9666314, 0173005899
Email-skrahim@apcbd.com
Bangladesh Internet Exchange Ltd
Rafel Kabir
House-26, Road-328, Block-K
Banani, Dhaka-1213.
Phone: 9893308-9
Email: info@bdnet.com.bd
Bangladesh Online Ltd.
Ershad Shafi Chowdhury
House 19, Road 35, Gulshan
Dhaka 1212
Phone: 8815559, 0171538734
Email: iru@bol-online.com
BDCOM Online Ltd.
Sumon Ahmed Shabir
House # 43, Road # 27(Old) 16 (New)
Dhanmondi R/A, Dhaka 1209
Phone: 8125074-5,8113792,8124699
Fax: 880-2-8122789
Email: office@bdcom.com
Bijoy Online Ltd.
Nawshad Ahmed
Bijoy Online Ltd.
Nawshad Ahmed
Basati Dream, Suit # A1
House No # 03, Road No # 20,
Gulshan – 1, Dhaka – 1212
Dhaka-1212.
Phone: 8820301-5, 0187040808
Fax : 88-02-8818299
Email: nawshad@bijoy.net
BRACNet Limited
Maj Gan Syeed Ahmed BP, awc, psc (retd.)
Chief Executive Officer
House 26, Road 28, Block K
Banani, Dhaka 1213
Phone: 9893333, Fax: 9884587
E-Mail: syeed.ahmed@bracmail.net, munirul.hoque@bracmail.net
Broadband Telecom Services Ltd.
Mahbubul Enam
General Manager
Ispahani Building (5th floor)
Agrabad C/A, Chittagong-4100
Phone: +88 031-2520550/6, 714126
Email: info@bbts.net
BTS Communications (BD) Ltd.
Abdul Kader
Swapnil-4, Mirzazangal
Sylhet - 3100, Bangladesh
Phone: 9860044, 821-715395, 0189257998
Email: bts@btsnet.net
CITech CyberNet Ltd
Subrata Sarker Shuvra
Aziz Bhaban (6th floor), 93,
Motijheel C/A, Dhaka-1000.
Tel- 7170990-1
Email-shuvra@citech.net
CGS Communication
Sayyedul Hoq
House -43, Road – 4/A
Dhanmondi, Dhaka
Phone- 8622485
E-mail- toufiq@cgscomm.net
Chittagong Online Limited
Engr. Tahmid Anwar
Managing Director
Arup Bhaban(2nd floor),
107, Agrabad C/A, Chittagong-4000
Phone: 031- 714447, 01713113113
Email: ceo@colbd.com
Communication One (pvt) ltd
Mohammad A.M.Muyeed
Erectors House,(12th floor)
18, kamal Ataturk Avenue
Banani, C/A, Dhaka-1213
Phone- 8861886
Connect BD Ltd.
Khandoker A. Al. Azad
House-42, Road-1/A, Block-1
Banani, Dhaka
Phone: 8816491-2, 0191328003
Email: azad@connectbd.com
CPM Blue Online Ltd
Khalequzzaman
Road-12/A, House-79, (4th floor),
Dhanmondi,R/A, Dhaka-1209.
Phone: 8154352, 8112458
Fax: 8753290
Email: s.sharif@cpm-bd.com
Cyberx IT Ltd.
S.M. Golam Faruk Alamgir
586/C, Khilgaon, R/A,(Ground Floor),
Dhaka
Phone: 7211616, 7212266
Email: arman@cyberxbd.com
Daffodil Online Ltd
S.M. Altaf Hossain
102, Shukrabad, Mirpur Road
Dhanmondi, Dhaka
Phone: 9143258-60, 0189212555
Email: ceo@daffodilnet.com
Data Edge Ltd
Mr.Md. Asifuzzaman
Sadharan Bima Bhaban-2
13th floor, 139, Motijheel, C/A
Dhaka-1000
Phone-7170368-70
E-Mail: asif@data-edge.com
Data Net Corporation Ltd.
Shaiful Alam
19/2, West Panthapath, Dhaka
Phone: 9113232
Email: litu@1postbox.com
Dekko Airnet Ltd.
Faisal Asif Rahman
T.K. Bhaban (17th Floor)
13, Kawran Bazar, Dhaka-1215.
Phone No : 9110268, 9112492
Fax : +880-2-8123608
E-mail : info@dekko.net.bd
Desh Online Services
Pronab Chatterjee
83/4, Kadamtala, East Bashaboo,
Dhaka-1214
Phone-7205304, 0189297853
Email: pronab@deshonline.net
Dhaka Com Ltd.
M.A. Hakim
Navana Tower (7th floor)
45 Gulshan South C/A Circle – 1, Dhaka
Phone: 8819220
Email: admindiv@dhakacom.com
Dominox Technologies Ltd
Anirban Bera
House-1/A, (5th floor), Road-23
Gulshan –1, Dhaka-1212.
Phone: 9894763-9894737
Email: anirban.bera@dominox.com
Drik ICT Ltd
S M Altaf Hossain
Managing Director & CEO
House- 58, Road-15/A
Dhanmondi Dhaka 1209
Phone: 9103222, Fax: 02-9110299
Cell: 01819 212 555
Email: ispab@drikict.net
Drishte Online Ltd
S. I.M. Alimgir
E-4, Monico Mina Tower
48/3, West Agargoan
Sher-e-Bangla Nagar
Dhaka-1207
E-mail- alamgir@smile.com.bd
Phone- 8115394
Druti Network Ltd
Dr. Md. Asaduzzaman Khan
House-28, Shahjalal Avenue,
Sector-04, Uttara, dhaka-1230
Tel- 8919173,8963963
Email-dr.asad@druti.net
Eastern Link BD (pvt) Ltd
Sujit Roy
48/3, Monico Mina Tower
West Agargoan
Sher-e-Bangla Nagar
Dhaka-1207
Phone- 8118708
E-mail-admin@smile.com.bd
Ektoo Limited
Pervez Sajjad
House:3, Road:7
Block:F, Banani
Dhaka 1213
Phone- +880-2-988-9175, 885-8131
www.ektoo.net.bd
Fusion Net
Nackshab Omar Rabbani Uthant
Managing Director
Navana Tower (22nd floor),
45, Gulshan Circle-1, Dhaka-1212
Phone: 8857502, 01711521512
Email: uthant@fusionbd.net
Geotel IT Ltd
Md. Majibul Hoque
69/1, Purana Paltan Line
Dhaka-1000.
Tel-8357325
Email-majib@xpeedgroup.com
Global Access Ltd.
Mr. Humayun Kabir
Grameen IT Park, Grameen Bank Bhaban
Mirpur-2, Dhaka-1216
Phone: 8011597, 9013363
Email: humayun@golbd.net
Global Information Network Ltd.
Ali Ashraf
Southland Center (5th Floor)
05- Agrabad, C/A, Chittagong
Phone- 031-726315-7
E-mail: ashraf@globalctg.net
Global Link Telecom Ltd
Abdullah A. Mamun
91, New Eskaton Road, Dhaka
Phone: 9332000
Email: amamun@glinktel.com
Grameen Cyber Net Ltd.
Azhar H. Chowdhury
RM Center 4th Floor
101 Gulshan Avenue
Dhaka-1212
Phone: 8812103, 8857809, 9886301-2
Email: azhar@citechco.net
HRC Technologies Ltd
Minhaz Uddin Foyez
26- Shyamoli,
Bir Uttam A.W.Chowdhury Road,
Dhaka-1207
Phone: 9131267
E-mail:minhaz.foyez@hrctech.net
Ichinet Ltd.
Dipak Bhattacharjee
10-HSS Road, Chittagong
Phone: 031-624932
Email: dipak@banol.net
IDEA Technologies.
Syed Osama Jalal
12/1, Salimullah Road
Mohammedpur, Dhaka-1207
Phone - 8159381, 01713043747
E-mail-osama@ideabd.net
IDS Bangladesh.
Barkatul Alam
Iqbal Centre, (5th floor)
42, Kamal Ataturk Avenue,
Banani, Dhaka- 1213
Phone- 8819449, 01713000554
Email: info@idsbangladesh.net
Information Services Network Ltd.
Mr. Habibul Alam ( Bir Protik)
TMC Building
52, New Eskaton Road, (4th floor)
Phone: 8322785-8
E-Mail: halam.isn@bangla.net
Innovative Online Limited
Mr.Shahriar Kabir
Jibon Bima Bhaban, 5th floor,
56, Agrabad, C/A, Chittagong-4100
Phone: 031-816778, 01911310473
Email: shahriar@iolbd.net
Insoft Systems Ltd.
Shoeb Chowdhury
Ahamed Tower (5th floor)
H#54/1, R@4/A, Dhanmondi
Phone: 8629027
Email: insoft@neksus.com
Intech Online ltd
Jami Mohammad Khan
3/1-H, Purana Paltan Dhaka-1000.
Phone: 9553886, 9553715
Email: jami@intechworld.net
International Computer Connections
Saiful Islam Siddique
BSRS Bhaban (4th floor),
12, Kawran Bazar, Dhaka-1215.
Phone: 9111514, 9110908
F ax : 8129734
Email: saiful@icc.com.bd
Is Pros Limited
Shah M Reaz
41/1, Kazi nazrul Islam Avenue
Zeenat Bhaban(5th floor)
Dhaka-1215
Phone- 8126957
E-mail – hasaan@isprosltd.com
Libra Computer Aid.
Javed Bukth
House-99, Road 11/A, Dhanmondi
Phone: 8112881, 8112908
Email: libra@bangla.net
Link3 Technologies Ltd.
F. M. Rashed Amin
Bulu Ocean Tower (16th Floor)
40 Kemal Attaturk Avenue, Banani.
Phone: 9892022, 8852219, 8854620
Fax : 9888642
Email: biddut@link3.net
Maisha Technologies Ltd
Mufti Mohammed Zahid
House-17, Road-3, Block-B
Bansree, Rampura, Dhaka.
Phone: 7286790, 7287600
Email: info@mtlbd.net
MB Telecom
Subrata Bardhan
13- Kawran Bazar
T.K. Bhaban (18th floor)
Dhaka-1215
Phone- 8150210-11
E-mail- subrata@inetbd.com
Metronet Bangladesh Ltd.
Syed Almas Kabir
12-Sonargaon Road 18th fl
Sonartori Tower, Dhaka-1000.
Phone: 9671381
Email: info@metrobd.net
Mirae Company Limited
Chang Hun Jang
North Tower, 8th Floor
107 Dhaka-Mymensing Road,
Sector-7, Uttara Model Town
Phone- 8954091, 8917873, 9891591
E-mail- sumon@miraebd.net
MLB Net
M. A. Juber Ahmed Khan
885-Old Hospital Road
Moulavibazar.
Phone: 0861-61378
Email: jbar@mlbd.net
M.R.Khan Joint International Trade Center
Moshiur Rahman Khan
Managing Director
New Town, Main Road, Madaripur.
Phone: 01711003507
Email: info@kolbd.net
Net Access Bangladesh
Mohammad Wasiuddin Rajesh
Meherba Plaza (9th floor)
33, Topkhana Road, Dhaka.
Phone: 9567405,9559233,9550654
Mobile: 0173004561
email: rajesh@sayboltgroup.com
New Generation Graphics Limited
Khadem Mahmud Yusuf
Safura Tower (13th floor)
20, Kamal Ataturk Avenue,
Banani, Dhaka.
Phone: 8856203, 8859365
Nextgen Networks Limited
Sefat-E-Sultana
Managing Director
1/2, Monipuripara, Tejgaon, Dhaka.
Phone: 9138726, 01678036602
Email: kmnalam@nextgen.net.bd
Nreach – net (pvt)ltd
Abdul Musabbir Ahmed
Nitol Center
71, Mohakhali, C/A
Dhaka-1212
Phone- 8833031
E-mail- arup@nreach.net.bd
Optimax Communication Ltd
Emdadul Huq
House: 90, Road: 23, Block: A
Banani, Dhaka-1213
Phone: 8853356,8853753
Email: emdad@optimaxbd.net
Poly IT Ltd
Md. Sanwar Hossain
52/2, Toyenbee Circular Road
Motijheel, Dhaka
Phone: 7125925
Email: sanwar75@hotmail.com
Pradeshta Ltd.
Samudra E Haque
House-24, Road-13/C, Block-E, Banani, Dhaka
Phone: 9882751, 9884674
Email: haqe@prodeshta.com
Proshika Computer Systems
Qazi Rubayet Ahmed
Proshika Bhaban, Section-2, Mirpur, Dhaka
Phone: 8012717
Email: rubayet@bdonline.com
Radiant Communications Ltd
Muhammed Nura Alam Bhuiyan
Managing Director
Suite A 3-4 & D 3-4, House-15, Road-17,
Kemal Ataturk Avenue, Banani, Dhaka -1213
Phone: 8834229, 01713227766
Email: shaibal@radiantbd.com
Ranks ITT Ltd
Mr. Iqbal Chowdhury
Redcrescent Borak Tower (Level 10)
37/3/A,Eskaton Garden Road,
71-72,Old Elephant Road,Eskaton
Dhaka-1000
Phone: 8361381
E-mail: info@ranksitt.net
Reve Systems
Rezaul Hassan
308-C, Mailbag Chowdhury Para
Dhaka-1219.
Phone: 7217330
Email: info@revesoft.com
Royal Green Online Ltd
33- Kawran Bazar (2nd Floor)
Dhaka-1215
Phone- 8142760-1, 8143347
E-mail- royalgreen.admin@gmail.com
Sirius Broadband (BD) Ltd
Mansur Habib
Awal Cene (17th floor)
34, Kamal Ataturk Avenue
Banani C/A, Dhaka
Phone: 9891843
Email: mansur@siriusbb.com
Software Shop Limited
Mahabub Morshed
27-28 Main Road Block-Kha
Section – 6, Mirpur, Dhaka
Phone: 8019179, 9116496
Email: cgl@concorde.bangla.net
Sorob IT Ltd.
Mohammed Billal Hossain
Kohinoor Tower-1, House- 7 (5th floor, E-1)
Road – 7, Gulshan-1, Dhaka-1212
Phone - 9895167, 01713033014
E-mail-billal@sorobit.com
Spark Systems Ltd
Salim Mohammod
House-43, Road-04, Sector-03
Uttara Model Town
Dhaka-1230
Phone- 8918091, 8919344
E-mail- info@sparkbd.net
Spectra Net Ltd 0020.
Faisal Jalil Chowdhury
Specatra Net Ltd, Sattar Chamber
99 Agrabad C/A, Chittagong
Phone: 031-710405-7
Email: fjasc@spnetctg.com
Square InformatiX Limited
Ahmed Ullah Bhuyian.
Square Centre, 48, Mohakhali C/A
Dhaka-1212.
Phone: 8817729-38, 011849899
E-mail: ahmed@squaregroup.com
Techno Online Ltd
Rubiyat Hossain
House-256, Road-6, CDA, Agrabad,
Chittagong-4100
Phone: 031-813133, 813704
Email: rubiyat@techno-bd.net
Telnet Communication Limited
Saiful Arefin Khaled
Director
House -04, Road -27,
Dhanmondi, Dhaka-1209
Phone : 8113999 , 8113333
Email : ispab@telnet.com.bd
Texas Electronics Ltd.
Kaiser Huda
Safura Tower (9th flr),
20 Kamal Ataturk Avenue Banani, Dhaka
Phone: 8861111
Email: info.tel@texasgroup.net
Westec Ltd.
Rabiul Hossain
H.H. Building (4th Floor)
52/1, New Eskaton
Dhaka.
Phone: 9352824
Email: info@bdlink.com
X-Net Limited
S. Shapir Khasr
1103, Concord Tower
113, Kazi Nazrul Islam Avenue
Dhaka-1000
Phoae- 8321051
E-mail – info@x-netbd.com
Thursday, 8 March 2012
How to block a Website
1. Click Start->All Programs->Accessories->Command Prompt.
2. Click Command Prompt This will open a DOS command window.
3. Type: notepad C:/Windows/System32/drivers/etc/hosts
4. Locate the line 127.0.0.1 localhost
5. To block the website google.com for example, just add this text under 127.0.0.1 localhost:
127.0.0.1 google.com
127.0.0.1 www.google.com
You can add as many sites any site, However you will need to prefix it with "127.0.0.1".
6. Save the file
Google will now be blocked in all web browser. This is an advanced but easy method on how to blow a website.
How to block a website
| For Business |
 |
 Windows 7, Vista, 2003, XP |
 |
| For Home |
 |
Windows 7, Vista, 2003, XP |
|
The hosts file method and blocking website by using Internet Explorer are free but can be easily bypassed. Another way is to use special software such as Employee Monitor (for Business) or HT Parental Controls (for Home), which lets you block website more effective and has many advantages.
How to block a website using the Hosts file
The location of the hosts file depends on your operation system.
Windows XP, Vista and Windows 7 C:\WINDOWS\system32\drivers\etc\hosts
Windows 2000 C:\WINNT\system32\drivers\etc\hosts
Note! Make a backup of the hosts file and put it somewhere safe, in case you mess up.
1. Open the hosts file using Notepad or other plain text editor.
2. Find the line 127.0.0.1 localhost
3. To block, for example, the website youtube.com, add this text under 127.0.0.1 localhost:
127.0.0.1 youtube.com
4. Save and close the Hosts file.
5. Reboot your computer to apply the changes.
6. Try to open www.youtube.com into a browser.
How to block a website on Internet Explorer
1. Open Internet Explorer and click on Tools
2. Click Internet Options
3. Click on the Content tab
4. Click the Enable button
5. Click on the Approved Sites tab
6. Type the website address you want to block in the box, for example, www.youtube.com
7. Click Never and then OK
8. In the appeared window type and confirm your new password
9. Click on the General tab and make sure to select Users can see websites that have no ratings
10. Click OK
How to block a website in spite of proxy servers
Unfortunately, the hosts file method and blocking a website by using Internet Explorer have a big imperfection. They can be easily bypassed. For example, web-based proxy servers allow getting a blocked website. Also, these methods are not universal and may not fit to a certain computer configuration and a type of a browser. So how to block a website in spite of proxy servers? The best way to block a website is our professional software.
How to block a website using HT Employee Monitor
1. Download and install HT Employee Monitor
2. Click the Block Websites button
3. Click the Add button.
4. In the appeared box, type the website address that you want to block or keyword,
for example, youtube.com
5. Click OK
HT Employee Monitor is easy to use and effective,
allowing you to restrict user activity and internet usage.
What you can
do with HT Employee Monitor:
-
Block
a website in the most popular browsers (Firefox, Internet Explorer, Opera,
Chrome, etc.)
- Block a specific website by URL
- Block a specific website by keywords
- Block a website by categories (Pornography, Gambling, Drugs, etc.)
- Disable any application (instant messengers,
browsers, programs, and so on)
- Track and record all your employees' computer activities (launched applications, typed keystrokes, visited web sites, system activity, screenshots and more).
HT Employee Monitor helps you to improve productivity
and efficiency of your employees.
Monday, 5 March 2012
আউটসোর্সিং: শুরুটা যেভাবে
আউটসোর্সিং: শুরুটা যেভাবে
আউটসোর্সিং: ইন্টারনেটের মাধ্যমে বিভিন্ন প্রতিষ্ঠান বিভিন্ন ধরনের কাজ করিয়ে নেয়। নিজ প্রতিষ্ঠানের বাইরে অন্য কাউকে দিয়ে এসব কাজ করানোকে আউটসোর্সিং বলে। যাঁরা আউটসোর্সিংয়ের কাজ করে দেন, তাঁদের ফ্রিল্যান্সার বলে। ফ্রিল্যান্সার মানে হলো মুক্ত বা স্বাধীন পেশাজীবী। আউটসোর্সিংয়ের কাজের খোঁজ থাকে, এমন সাইটে যিনি কাজটা করে দেন, তাঁকে বলা হয় কনট্রাকটর (তিনি কনট্রাক্টে কাজ করেন)। আর যিনি কাজ দেন, তাঁকে বলে বায়ার/এমপ্লয়ার (তিনি কনট্রাক্টে কাজ দেন)।
যে ধরনের কাজ পাওয়া যায়: আউটসোর্সিং সাইট বা অনলাইন মার্কেট প্লেসে কাজগুলো বিভিন্ন ভাগে ভাগ করা থাকে। যেমন: ওয়েব ডেভেলপমেন্ট, সফটওয়্যার ডেভেলপমেন্ট, নেটওয়ার্কিং ও তথ্যব্যবস্থা (ইনফরমেশন সিস্টেম), লেখা ও অনুবাদ, প্রশাসনিক সহায়তা, ডিজাইন ও মাল্টিমিডিয়া, গ্রাহকসেবা (Customer Service), বিক্রয় ও বিপণন, ব্যবসাসেবা ইত্যাদি।
ওয়েব ডেভেলপমেন্ট: এই বিভাগের মধ্যে আছে আবার ওয়েবসাইট ডিজাইন, ওয়েব প্রোগ্রামিং, ই-কমার্স, ইউজার ইন্টারফেস ডিজাইন, ওয়েবসাইট টেস্টিং, ওয়েবসাইট প্রজেক্ট ম্যানেজমেন্ট ইত্যাদি।
সফটওয়্যার ডেভেলপমেন্ট: সফটওয়্যার ডেভেলপমেন্টর মধ্যে আছে ডেস্কটপ অ্যাপ্লিকেশন, গেম ডেভেলপমেন্ট, স্ক্রিপ্ট ও ইউটিলিটি, সফটওয়্যার প্লাগ-ইনস, মোবাইল অ্যাপ্লিকেশন, ইন্টারফেস ডিজাইন, সফটওয়্যার প্রকল্প-ব্যবস্থাপনা, সফটরয়্যার টেস্টিং, ভিওআইপি ইত্যাদি।
নেটওয়ার্কিং ও ইনফরমেশন সিস্টেম: এর মধ্যে আছে নেটওয়ার্ক অ্যাডমিনিস্ট্রেশন, ডিবিএ-ডাটাবেজ অ্যাডমিনিস্ট্রেশন, সার্ভার অ্যাডমিনিস্ট্রেশন, ইআরপি/সিআরএম ইমপ্লিমেনটেশন ইত্যাদি।
রাইটিং ও ট্রান্সলেশন: এর মধ্যে আছে কারিগরি নিবন্ধ লেখা (টেকনিক্যাল রাইটিং), ওয়েবসাইট কনটেন্ট, ব্লগ ও আর্টিকেল রাইটিং, কপি রাইটিং, অনুবাদ, ক্রিয়েটিভ রাইটিং ইত্যাদি।
অ্যাডমিনিস্ট্রেটিভ সাপোর্ট: এর মধ্যে আছে ডেটা এন্ট্রি, পারসোনাল অ্যাসিসট্যান্ট, ওয়েব রিসার্চ, ই-মেইল রেসপন্স হ্যান্ডলিং, ট্রান্সক্রিপশন ইত্যাদি।
Sunday, 4 March 2012
About Networking
Networking:
Networking means connecting two or
more devices (nodes) for communication purpose. A node can be a computer,
printer, or any other device capable of sending and/or receiving data generated
by other nodes on the network.
Computer Network:
A computer network is a group of interconnected computer or A computer network is any set of
computers or devices connected to each other with the ability to exchange data.
Types of networks:
Local Area Network (LAN): A network covering a small geographic
area, like a home, office, or building. Current LANs are most likely to be
based on Ethernet technology. For example, a library may have a wired or
wireless LAN for users to interconnect local devices (e.g., printers and
servers) and to connect to the internet. On a wired LAN, PCs in the library are
typically connected by category 5 (Cat5) cable, running the IEEE 802.3 protocol
through a system of interconnection devices and eventually connect to the
internet.
Metropolitan Area Network (MAN): A Metropolitan Area Network is a network
that connects two or more Local Area Networks or Campus Area Networks together
but does not extend beyond the boundaries of the immediate town/city. Routers,
switches and hubs are connected to create a Metropolitan Area Network.
Wide Area Network
(WAN): A WAN is a data communications network that covers a
relatively broad geographic area (i.e. one city to another and one country to
another country) and that often uses transmission facilities provided by common
carriers, such as telephone companies.
Global Area Network
(GAN): Global area networks (GAN) specifications are in development
by several groups, and there is no common definition. In general, however, a
GAN is a model for supporting mobile communications across an arbitrary number
of wireless LANs, satellite coverage areas, etc.
Internetwork: Two or more
networks or network segments connected using devices, such as a router. Any
interconnection among or between public, private, commercial, industrial, or
governmental networks may also be defined as an internetwork. In modern
practice, the interconnected networks use the Internet Protocol. There are at
least three variants of internetwork, depending on who administers and who
participates in them:
- Intranet
- Extranet
- Internet
Intranet: An intranet is a set of networks,
using the Internet Protocol and IP-based tools such as web browsers and file
transfer applications, that is under the control of a single administrative
entity. That administrative entity closes the intranet to all but specific,
authorized users. Most commonly, an
intranet is the internal network of an organization. A large intranet will
typically have at least one web server to provide users with organizational
information.
Extranet: An extranet is a network or
internetwork that is limited in scope to a single organization or entity but
which also has limited connections to the networks of one or more other
usually, but not necessarily, trusted organizations or entities (e.g. a
company's customers may be given access to some part of its intranet creating
in this way an extranet, while at the same time the customers may not be
considered 'trusted' from a security standpoint). Technically, an extranet may
also be categorized as a CAN, MAN, WAN, or other type of network, although, by
definition, an extranet cannot consist of a single LAN; it must have at least
one connection with an external network.
Internet: The
Internet is a specific internetwork. It consists of a worldwide interconnection
of governmental, academic, public, and private networks based upon the
networking technologies of the Internet Protocol Suite. It is the successor of
the Advanced Research Projects Agency Network (ARPANET) developed by DARPA of
the U.S. Department of Defense. The Internet is also the communications
backbone underlying the World Wide Web (WWW). The 'Internet' is most commonly
spelled with a capital 'I' as a proper noun, for historical reasons and to
distinguish it from other generic internetworks.
Participants
in the Internet use a diverse array of methods of several hundred documented,
and often standardized, protocols compatible with the Internet Protocol Suite
and an addressing system (IP Addresses) administered by the Internet Assigned
Numbers Authority and address registries. Service providers and large
enterprises exchange information about the reachability of their address spaces
through the Border Gateway Protocol (BGP), forming a redundent world-wide mesh
of transmission paths.
Network
topology:
Computer networks may be classified according to
the network topology upon which the network is based, such as Bus network, Star
network, Ring network, Mesh network, Star-bus network, Tree or Hierarchical
topology network, etc.Network Topology signifies the way in which devices in
the network see their logical relations to one another. The use of the term
"logical" here is significant. That is, network topology is independent
of the "physical" layout of the network. Even if networked computers
are physically placed in a linear arrangement, if they are connected via a hub,
the network has a Star topology, rather than a Bus Topology. In this regard the
visual and operational characteristics of a network are distinct; the logical
network topology is not necessarily the same as the physical layout.
Open Systems and the Open Systems Interconnection (OSI) model:
A set of protocols
that would allow any two different systems to communicate regardless of their
underlying architecture is called an open system. The ISO has addressed the
problem of allowing many devices to communication and has developed its Open
System Interconnect (OSI) model. If fully developed, it would allow any two
computers to communicate provided they are connected.
In its most basic form, it divides network
architecture into seven layers which, from top to bottom, are the Application,
Presentation, Session, Transport, Network, Data-Link, and Physical Layers. It
is therefore often referred to as the OSI Seven Layer.
Description of Open Systems Interconnection(OSI) layers
OSI
Model
|
|||
Data
unit
|
Layer
|
Function
|
|
Host
layers |
Data
|
1. Application
|
Network
process to application
|
2. Presentation
|
Data
representation and encryption
|
||
3. Session
|
Interhost
communication
|
||
Segment/Datagram
|
4. Transport
|
End-to-end
connections and reliability
|
|
Media
layers |
Packet
|
5. Network
|
Path
determination and logical addressing
|
Frame
|
6. Data Link
|
Physical
addressing (MAC & LLC)
|
|
Bit
|
7. Physical
|
Media,
signal and binary transmission
|
|
Network Interface Cards: A network card, network adapter
or NIC (network interface card) is a piece of computer hardware designed
to allow computers to communicate over a computer network. It
provides physical access to a networking medium and often provides a low-level
addressing system through the use of MAC addresses. It allows users to connect
to each other either by using cables or wirelessly.
1.Repeaters: repeater is an electronic device that receives a signal
and retransmits it at a higher level or higher power, or onto the other side of
an obstruction, so that the signal can cover longer distances without
degradation. In most twisted pair Ethernet configurations, repeaters are
required for cable runs longer than 100 meters.
2.Hubs: hub contains multiple ports. When a packet
arrives at one port, it is copied to all the ports of the hub for transmission.
When the packets are copied, the destination address in the frame does not
change to a broadcast address. It does this in a rudimentary way, it simply
copies the data to all of the Nodes connected to the hub.
3.Bridges: A network bridge connects multiple network
segments at the data link layer (layer 2) of the OSI model. Bridges do not
promiscuously copy traffic to all ports, as hubs do, but learns which MAC
addresses are reachable through specific ports. Once the bridge associates a
port and an address, it will send traffic for that address only to that port.
Bridges do send broadcasts to all ports except the one on which the broadcast
was received. Bridges learn the association of ports and addresses by examining
the source address of frames that it sees on various ports. Once a frame
arrives through a port, its source address is stored and the bridge assumes
that MAC address is associated with that port. The first time that a previously
unknown destination address is seen, the bridge will forward the frame to all
ports other than the one on which the frame arrived.
Bridges
come in three basic types:
- Local bridges: Directly connect local area networks (LANs)
- Remote bridges: Can be used to create a wide area network (WAN) link between LANs. Remote bridges, where the connecting link is slower than the end networks, largely have been replaced by routers.
- Wireless bridges: Can be used to join LANs or connect remote stations to LANs.
4.Switches: A switch is a device that performs
switching. Specifically, it forwards and filters OSI layer 2 datagrams (chunk
of data communication) between ports (connected cables) based on the
Mac-Addresses in the packets. This is distinct from a hub in that it only
forwards the datagrams to the ports involved in the communications rather than
all ports connected. Strictly speaking, a switch is not capable of routing
traffic based on IP address (layer 3) which is necessary for communicating
between network segments or within a large or complex LAN. Some switches are
capable of routing based on IP addresses but are still called switches as a
marketing term. A switch normally has numerous ports with the intention that
most or all of the network be connected directly to a switch, or another switch
that is in turn connected to a switch.
5.Routers: Routers are networking devices that
forward data packets between networks using headers and forwarding tables to
determine the best path to forward the packets. Routers work at the network
layer of the TCP/IP model or layer 3 of the OSI model. Routers also provide
interconnectivity between like and unlike media (RFC 1812). This is
accomplished by examining the Header of a data packet, and making a decision on
the next hop to which it should be sent (RFC 1812) They use preconfigured
static routes, status of their hardware interfaces, and routing protocols to
select the best route between any two subnets. A router is connected to at
least two networks, commonly two LANs or WANs or a LAN and its ISP's network.
Some DSL and cable modems, for home (and even office) use, have been integrated
with routers to allow multiple home/office computers to access the Internet
through the same connection. Many of these new devices also consist of wireless
access points (waps) or wireless routers to allow for IEEE 802.11b/g wireless
enabled devices to connect to the network without the need for a cabled
connection.
Protocols:
A protocol is a set of rules that
governs data communication to occur. It defines the format and the order of
message exchanged between two or more communication entities, as well as the
actions taken on the transmission and/or receipt of a message or other event. A
protocol defines what is communicated, how it is communicated, and when it is
communicated. Without protocol two computer can be connected but not
communicate. It is essential to use same protocol for communication between two
devices. When several protocols work at a time it is called protocol suit. At
present three widely used protocol suits are TCP/IP, IPX/SPX and AppleTalk.
Connection-Oriented and Connectionless services:
When an application uses the
connection-oriented service, the client program and the server program send
control packets to each other before sending packets with the actual data to be
transferred. This so called handshaking procedure alerts client and server,
allowing them to prepare for an onslaught of data packets. Once the handshaking
procedure is finished, a connection is said to be established between the two
end systems. The Internet connection oriented service has a name
-Transmission Control Protocol
(TCP); the initial version of TCP protocol is defined in the Internet Request
for Comments RFC 793.
There is no handshaking with the
Internet’s connectionless service. When one side of an application wants to
send packets to other side of the application, the sending program simply sends
the packets. Since there is no handshaking procedure prior to data packet
transmission, data can be deliver sooner. A source never knows for sure which
packets have arrived at the destination. The Internet’s connectionless service
is called User Datagram Protocol (UDP); UDP is define in the Internet Request
for Comments RFC 768.
Routing Protocols: A routing protocol sends and receives routing
information packets to and from other routers. Routing protocols implement
algorithms that tell routers the best paths through internetworks. Routing
protocols include Border Gateway Protocol (BGP), Interior Gateway Routing
Protocol (IGRP), Routing Information Protocol, and Open Shortest Path First
(OSPF) to name a few. Routing protocols provide the layer 3 network state
update.
Routed Protocols: A routed protocol can be routed by a router,
which means that it can be forwarded from one router to another. Such as
Internet Protocol (IP), Novell Internetwork Packet eXchange (IPX), and
AppleTalk are routed protocols.
In short, routing protocols
route datagrams through a network. Routing is a layer 3 function, thus, routing
and routed protocols are network-layer entities. Routing tables on the layer 3
switch (router) are populated by information from routing protocols. A routed
protocol will enter an interface on a router, be placed in a memory buffer,
then it will be forwarded out to an interface based on information in the
routing table.
Routed versus routing protocols:
Confusion often arises between routing protocols and routed
protocols. While routing protocols help the router in the decision-making
on which paths to send traffic, routed protocols are responsible for the actual
transfer of traffic between Layer3 devices. Specifically, a routed protocol is
any network protocol that provides enough information in its network layer
address to allow a packet to be forwarded from one host to another host based
on the addressing scheme, without knowing the entire path from source to
destination. Routed protocols define the format and use of the fields
within a packet. Packets generally are conveyed from end system to end system.
Internet Address or IP:
IP address is a network layer
protocol address for a host in a TCP/IP network. IP address is used to uniquely
identify each host in a network. An IP address in the current version of protocol
is a 32-bit binary address that uniquely and universally defines the connection
of a host or a router to the Internet. IP address is needed in order to
communicate with other hosts in the network using the TCP/IP suite of
protocols.
IP Addresses are Unique:
The IP addresses are unique in
the sense of that each address define one, and only one, connection in the Internet
Two device on the internet can never have the same address at the same
time. However, if a device has two
connections to the Internet, via two networks, it has two IP address.
IP Addresses are Universal:
The IP addresses are Universal in
the sense that the addressing system must be accepted by any host that wants to
connected to the Internet.
Originally,
an IP address was defined as a 32-bit number and this system, now
named Internet Protocol Version 4 (IPv4), is still in use today. However, due
to the enormous growth of the Internet and the resulting depletion of the
address space, a new addressing system (IPv6), using 128 bits for the address,
had to be developed. IPv6 is now being deployed across the world; in many
places it coexists with the old standard and is transmitted over the same
hardware and network links. This
document only covers IPv4.
There are two common notations to show an
IP address: Binary notation and dotted decimal notation.
In binary notation, the IP address is displayed as
32 bits. To make the address more readable, one or more spaces is usually
inserted between each octet (8 bit). The following example of an IP address. In
binary notation: 11000000 10101000
00000000 00000011.
In decimal notation: 192.168.0.3
Each IP address divided into two parts: Network ID or Netid + Host ID or Hostid
In a specific network, Network ID of each IP address is same
but Host ID must be different.
IP versions
Two versions of the Internet Protocol (IP) are in use: IP Version 4 and IP Version 6. Each version defines an IP address differently. Because of its prevalence, the generic term IP address typically still refers to the addresses defined by IPv4. The gap in version sequence between IPv4 and IPv6 resulted from the assignment of number 5 to the experimental Internet Stream Protocol in 1979, which however was never referred to as IPv5.IPv4 addresses
Main article: IPv4#Addressing
IPv4 addresses are canonically represented in dot-decimal notation, which consists of four decimal numbers, each ranging from 0 to 255, separated by dots, e.g., 172.16.254.1. Each part represents a group of 8 bits (octet) of the address. In some cases of technical writing, IPv4 addresses may be presented in various hexadecimal, octal, or binary representations.
IPv4 subnetting
In the early stages of development of the Internet Protocol,[1] network administrators interpreted an IP address in two parts: network number portion and host number portion. The highest order octet (most significant eight bits) in an address was designated as the network number and the remaining bits were called the rest field or host identifier and were used for host numbering within a network.This early method soon proved inadequate as additional networks developed that were independent of the existing networks already designated by a network number. In 1981, the Internet addressing specification was revised with the introduction of classful network architecture.[2]
Classful network design allowed for a larger number of individual network assignments and fine-grained subnetwork design. The first three bits of the most significant octet of an IP address were defined as the class of the address. Three classes (A, B, and C) were defined for universal unicast addressing. Depending on the class derived, the network identification was based on octet boundary segments of the entire address. Each class used successively additional octets in the network identifier, thus reducing the possible number of hosts in the higher order classes (B and C). The following table gives an overview of this now obsolete system.
| Class | Leading bits in address (binary) | Range of first octet (decimal) | Network ID format | Host ID format | Number of networks | Number of addresses per network |
|---|---|---|---|---|---|---|
| A | 0 | 00000000-01111111 0 - 127 |
a | b.c.d | 27 = 128 | 224 = 16777216 |
| B | 10 | 10000000-10111111 128–191 |
a.b | c.d | 214 = 16384 | 216 = 65536 |
| C |
110 |
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