by Dinesh Thakur Category: Communication Networks

This advises the routers are used to connect dissimilar LANs and perform all the functions of bridges and routers. It operates at all seven layers of the OSI Reference Model. These are actually predecessors of router nowadays and are technology wise more expensive and highly functional. They in general consist of software which resides in a host computer, such as mid-range or mainframe.

OSI Correspondence of Gateways Interconnection Between Ethernet and Mainframe using Gateway

Characteristics of Gateways 

  1. Gateways provide full protocol conversion from one proprietary LAN technology to another, i.e. Ethernet to token ring or FDDI or any other standard or protocol rather than encapsulation
  2. It uses higher layers of the OSI model, perhaps through layer 7, the application layer. IBM SNA, DECnet, Internet TCP/IP and other protocols can be converted from network-to-network
  3. Unlike bridges and routers, gateways operate slowly because of protocol conversion. Consequently, they may create bottlenecks of congestion during periods of peak usage.

Default Gateway

Default gateway consists of manually registering router IP addresses in the host. This method is simple; and is the most frequently used. Note however, that if two or more routers are connected to the same subnet, the network administrator must determine which of these routers the message should be sent to. To solve this problem, a message called ICMP redirect is available. Default gateway checks the destination host address in the received message. If it determines that the message should be sent via other router, it will send back a redirect message that includes the IP address of the selected router, to the source host. When the source host receives this message, it stores the destination host address as well as the second router address so that it can send messages addressed to this host via the second router.

                                   Default Gateway

 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.



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