Comprehensive analysis of three common router protocols

Source: Internet
Author: User

Currently, the vro protocol is widely used. Many people may not know the RIP, HELLO, and egp in the vro protocol. It does not matter. After reading this article, you will certainly have a lot of GAINS, I hope this article will teach you more things. Technically, the IGP protocol is the same as RIP and HELLO protocol. Vro uses this Protocol to obtain information about other vro protocols in the autonomous system so as to update its routing table. Unlike the internal Router Protocol, EGP also performs other work in addition to the usual routing table.

The vro protocol running EGP communicates with other Autonomous Systems for reachable information. It is independent of its own routing table. In this way, a UNIX program of RIP is routed, which notifies the information obtained from the local selector table and changes the local selector table when receiving the update information. It is correct to trust the data sent by the machine running RIP. On the contrary, the program implementing EGP does not advertise the route obtained from the local routing table; it retains an independent database for the accessible information of the network.

When the vro protocol running EGP advertises reachable information, you must note that only authorized advertised routes can be transmitted. Otherwise, other parts of the interconnected network will be affected. For example, a route in an autonomous system occasionally broadcasts a non-existent route with a distance of 0 to the University of Perdu, the RIP Protocol will enable other router protocols to recognize this route and forward the traffic to the correct router. In this way, the communication traffic of the autonomous system where these router protocols are located cannot reach the university. If EGP broadcasts this error to a machine outside the autonomous system, some parts of the interconnected network will not be able to reach the university of Perdu.

The gated Program combines multiple IGP and EGP rules to broadcast routes to the external Router Protocol according to a series of restrictions to form a whole. For example, gated can receive RIP packets and modify the route table of the local machine as the routed program. It uses EGP to advertise the routes accessible from the local autonomous system. These rules allow administrators to specify which networks can be advertised. Therefore, although the gated program is not a member of the IGP protocol family, it plays an important role in the routing process, it demonstrates that it is feasible to establish an automatic mechanism to link IGP and EGP without sacrificing security performance.

Another performance of the Gated program is to convert distance measurement standards. Specifically, the distance used when the router protocol in the autonomous system advertises the route is under a fixed limit of 128. The distance measurement used by the external Router Protocol to advertise routes that span autonomous systems but have not exceeded the consortium of autonomous systems must be converted to a high range of 128 to 191 ), such a conversion mechanism artificially increases the cost of routing outside the autonomous system, so that the traffic flow within the autonomous system as much as possible. Finally, for routes beyond the Autonomous System Consortium, the distance value is converted to a higher range of 192 to 254) so as to make the traffic flow within the Autonomous System Consortium as much as possible. As the gated program provides interfaces between autonomous systems, this conversion operation can be easily implemented.

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.