Router
A hardware device designed to take incoming packets, analyze the packets, moving the packets to another network, converting the packets to another network interface,
dropping the packets, directing packets to the appropriate locations,
and performing any other number of other actions. The picture shows the
Linksys BEFSR11 router and is what most home routers resemble.
A router has a lot more capabilities than other network devices such as a hub or a switch that are only able to perform basic network functions. For example, a hub is often used to transfer data between computers or network devices, but does not analyze or do anything with the data it is transferring. Routers however can analyze the data being sent over a network, change how it is packaged and send it to another network or over a different network. For example, routers are commonly used in home networks to share a single Internet connection with multiple computers.
In
the above example of a home network there are two different examples of
a router, the router and the wireless router. As can be seen in the
example the router is what allows all the computers and other network
devices access the Internet. Below are some additional examples of different types of routers used in a large network.
A router has a lot more capabilities than other network devices such as a hub or a switch that are only able to perform basic network functions. For example, a hub is often used to transfer data between computers or network devices, but does not analyze or do anything with the data it is transferring. Routers however can analyze the data being sent over a network, change how it is packaged and send it to another network or over a different network. For example, routers are commonly used in home networks to share a single Internet connection with multiple computers.
Brouter
Short for Bridge Router, a "brouter" is a networking device that serves as both a bridge and a router.
Core router
A core router is a router in a computer network that routes data within a network, but not between networks.
Edge router
An edge Router is a router in a computer network that routes data between one or more networks.
Virtual router
A Virtual Router is a backup router used in a VRRP setup.
Wireless router
See the access point definition for further information.
router
(row´ter) (n.) A router is a device that forwards data packets along networks. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISP's network. Routers are located at gateways, the places where two or more networks connect.
Routers use headers and forwarding tables to determine the best path for forwarding the packets, and they use protocols such as ICMP to communicate with each other and configure the best route between any two hosts.
Very little filtering of data is done through routers.
Last of the IPv4 Addresses Allocated
Early this morning, the Asia Pacific Network Information Centre
(APNIC) announced that it had been allocated two /8 address blocks from
the Internet Assigned Numbers Authority (IANA
). Those two blocks, 39/8 and 106/8, were the last unallocated blocks in
the IANA free pool of IPv4 address available to Regional Internet
Registries (RIR). With the allocation, the final days of IPv4 have
moved closer as the number of available addresses that can be allocated
will dwindle.
"Please be aware, this will be the final allocation made by IANA under the current framework and will trigger the final distribution of five /8 blocks, one to each RIR under the agreed global policy for the allocation of the remaining IPv4 address space,” APNIC wrote on its website.
IANA has scheduled a press conference for Thursday morning to discuss the final allocation of the last five blocks of IPv4 space. The policy of distributing the final five equally among the RIRs is a long standing policy designed for the endgame of IPv4.
While the IANA free pool is now gone, that doesn't mean that IPv4
address space itself has been exhausted. The RIRs make requests from
IANA for free, unallocated space which is then allocated by the RIRs to
carriers and businesses. Each /8 allocation includes approximately 16
million addresses. In total, there could be 4.3 billion IPv4 addresses
in use, were they all fully allocated.
APNIC expects to continue to make normal allocations of IPv4 address space to its constituents for the next three to six months. After that, it will grant only smaller blocks of address space that could extend the allocation another five years.
In the U.S., the American Registry for Internet Numbers (ARIN) is the RIR responsible for address allocation. John Curran, CEO of ARIN, told InternetNews.com that as of January 1, 2011 (the date of the last number resource report), ARIN had the equivalent of 4.92 /8 blocks. Curran was not able to specify when ARIN will actually run out of IPv4 address space to allocate.
"We have no official forecast, and any estimate would change rapidly depending on requests received," Curran said. "Based on solely historical tendencies, 6 to 9 months from final IANA allocation till ARIN exhaustion would not be an unreasonable expectation."
To date, IPv6 adoption has been slow, though the RIRs have been advocating for its adoption.
"The RIRs have been working with network operators at the local, regional, and global level for more than a decade to offer training and advice on IPv6 adoption and ensure that everyone is prepared for the exhaustion of IPv4," Axel Pawlik, managing director of RIPE (Réseaux IP Européens), the RIR for Europe told InternetNews.com. "Post IPv4 depletion, RIPE will continue to distribute Internet number resources, including IPv6 addresses."
Pawlik added that the transition to IPv6 from IPv4 represents an opportunity for even more innovative applications without the fear of running out of essential Internet IP addresses.
Though IPv4 is now nearly exhausted, the move to IPv4 will take time. The Internet Society has scheduled World IPv6 day for June to test the addressing system on major websites including Google and Facebook, but there is still work to be done. The immediate future is not a move away from IPv4, but rather a move to include IPv6.
"Internet users need to realize that the Internet will be in transition over several years, with both IPv4 and IPv6 running in parallel," ARIN's Curran said. "Organizations need to IPv6 enable their Web site, so that both existing IPv4 and new IPv6-connected Internet users can directly access it."
Sean Michael Kerner is a senior editor at InternetNews.com, the news service of Internet.com, the network for technology professionals.
"Please be aware, this will be the final allocation made by IANA under the current framework and will trigger the final distribution of five /8 blocks, one to each RIR under the agreed global policy for the allocation of the remaining IPv4 address space,” APNIC wrote on its website.
IANA has scheduled a press conference for Thursday morning to discuss the final allocation of the last five blocks of IPv4 space. The policy of distributing the final five equally among the RIRs is a long standing policy designed for the endgame of IPv4.
Operationalizing the Network: SDN
APNIC expects to continue to make normal allocations of IPv4 address space to its constituents for the next three to six months. After that, it will grant only smaller blocks of address space that could extend the allocation another five years.
In the U.S., the American Registry for Internet Numbers (ARIN) is the RIR responsible for address allocation. John Curran, CEO of ARIN, told InternetNews.com that as of January 1, 2011 (the date of the last number resource report), ARIN had the equivalent of 4.92 /8 blocks. Curran was not able to specify when ARIN will actually run out of IPv4 address space to allocate.
"We have no official forecast, and any estimate would change rapidly depending on requests received," Curran said. "Based on solely historical tendencies, 6 to 9 months from final IANA allocation till ARIN exhaustion would not be an unreasonable expectation."
More impetus for the IPv6 migration
With freely available, unallocated IPv4 addresses almost gone, the move to the next generation IPv6 addressing system which provides significantly more address space than IPv4 must begin in earnest. IPv6 has a 128 bit addressing system that can provide 340 trillion trillion trillion (34 x 10 to the 38th power) Internet addresses.To date, IPv6 adoption has been slow, though the RIRs have been advocating for its adoption.
"The RIRs have been working with network operators at the local, regional, and global level for more than a decade to offer training and advice on IPv6 adoption and ensure that everyone is prepared for the exhaustion of IPv4," Axel Pawlik, managing director of RIPE (Réseaux IP Européens), the RIR for Europe told InternetNews.com. "Post IPv4 depletion, RIPE will continue to distribute Internet number resources, including IPv6 addresses."
Pawlik added that the transition to IPv6 from IPv4 represents an opportunity for even more innovative applications without the fear of running out of essential Internet IP addresses.
Though IPv4 is now nearly exhausted, the move to IPv4 will take time. The Internet Society has scheduled World IPv6 day for June to test the addressing system on major websites including Google and Facebook, but there is still work to be done. The immediate future is not a move away from IPv4, but rather a move to include IPv6.
"Internet users need to realize that the Internet will be in transition over several years, with both IPv4 and IPv6 running in parallel," ARIN's Curran said. "Organizations need to IPv6 enable their Web site, so that both existing IPv4 and new IPv6-connected Internet users can directly access it."
Sean Michael Kerner is a senior editor at InternetNews.com, the news service of Internet.com, the network for technology professionals.
IP address - Internet Protocol (IP) address
IP address is short for Internet Protocol (IP) address. An IP address is an identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol route messages based on the IP address of the destination.
What is My IP Address?
To view your IP address you can use the ipconfig (IPCONFIG) command line tool. Ipconfig displays all current TCP/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings.You can also use Google search to find your IP address. Type what is my IP address as a search query and Google will show the IP address of the computer from which the query was received as the top search result.
The Format of an IP Address
The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 1.160.10.240 could be an IP address.Within an isolated network, you can assign IP addresses at random as long as each one is unique. However, connecting a private network to the Internet requires using registered IP addresses (called Internet addresses) to avoid duplicates.
An IP address can be static or dynamic. A static IP address will never change and it is a permanent Internet address. A dynamic IP address is a temporary address that is assigned each time a computer or device accesses the Internet.
Editor's recommendation: Understanding IP Addressing.
The four numbers in an IP address are used in different ways to identify a particular network and a host on that network. Four regional Internet registries -- ARIN, RIPE NCC, LACNIC and APNIC-- assign Internet addresses from the following three classes:Class A - supports 16 million hosts on each of 126 networks
Class B - supports 65,000 hosts on each of 16,000 networks
Class C - supports 254 hosts on each of 2 million networks
The number of unassigned Internet addresses is running out, so a new classless scheme called CIDR is gradually replacing the system based on classes A, B, and C and is tied to adoption of IPv6. In IPv6 the IP address size is increased from 32 bits to 128 bits.
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