In-depth introduction to the routing cluster technology of Ge-switched Routers

With the development of China's routing industry, it also promotes the update and upgrade of the routing cluster technology. Here we mainly analyze the comprehensive analysis of the routing cluster technology of the Gigabit exchange router. Currently, IP has become the routing protocol for most backbone network products. In some network environments, users have high requirements on the network, and any shutdown and storage and transportation losses will have a serious impact on users.

1. Internet service providers provide Web host devices. To make your Web server always valid for the public, 99.9999% of the normal running time of the user must be guaranteed.

2. The process control application must be able to access its control system in a timely manner, otherwise there may be serious results loss control.

3. Sometimes, applications running on the IP host will time out. If the service runs requires a high level of network applications, this timeout will have a bad impact.

More and more IP hosts use DHCP to specify their IP addresses. However, many IP hosts use manual configuration as the only means to discover Gateway Routing addresses. Some hosts use the gateway detection method, but generally do not use this method RFC1122). Dynamic Ping to the gateway is also prohibited. The ICMP routing discovery protocol allows routers to be discovered through IP hosts, but it is not widely used. This means that most hosts cannot quickly know whether the connection between the vro and the connected lan has failed, and it takes a long time for the IP host to detect the connection failure and exchange the replacement vro. Therefore, it is important for any device to improve the network efficiency. Using vro cluster technology can effectively solve some problems. This article introduces the SSR Gigabit Exchange Routing cluster technology of CABLETRON for some discussion.

The vro cluster technology can be used to define multiple SSR routers in the same LAN as clusters for Route backup between each other, the SSR router in the cluster uses the IETF virtual redundancy Routing Protocol to implement Images Between route switches and the LAN of Each router. If a router or the LAN connected to it fails, other routers will automatically replace the failed router to bypass the fault point and re-route the route. The route recovery time is within several seconds. Therefore, this is a transparent application running on the IP host.

VRRP Concept

As shown in figure 1, VRRP can provide a backup router when the default gateway of the workstation fails. VRRP can create a vro with a virtual MAC address and virtual IP address. It is true that we can add multiple default gateways in Windows 98, but this feature can only be used when the host is started. In other words, when the host is started, the first default gateway in the gateway list uses ARP for address resolution. If the resolution fails, Other gateways in the list continue to perform address resolution.

What happens when the host finds the MAC address of the default gateway? You can only restart the host to continue searching for the next default gateway. VRRP can be used to solve this problem because it is dynamically changing. If the primary router is paralyzed, the backup router automatically replaces the primary router. The host is unaware of any difference. The virtual routing cluster technology is integrated into SSR as a module to ensure the practicability of network applications and improve the reliability and adaptability of networks with high application requirements. CABLETRON's virtual routing cluster technology follows the VRRP virtual redundancy routing protocol developed by IETFInternet engineering task group.

In Figure 2, IP host H1 and H2 are connected to a LAN with multiple routers, such as R1 and R2.) R1 and R2 provide a connection to the destination D1. Under normal circumstances, only the routing IP addresses of a single router, such as H1 and H2, are configured. The problem is that when any router fails, one or more hosts, such as H1 and H2, are connected to the destination D1. For general routing protocols such as RIP and OSPF, it may take about 40-90 seconds for the host H1 and H2 to discover a route failure. When VRRP is used in vro cluster technology, it takes only a few seconds to restore the failed route in the network. This greatly improves the network efficiency, provides route redundancy for network applications that require picky backbone.