Motivations for Traffic Engineering
To reduce the costs of operating and maintaining separate network infrastructures, an increasing number of service providers are migrating their legacy Layer 2 and emerging Layer 3 services onto a common packet-switched network. The converged network architecture is expected to deliver reliable and scalable differentiated services. To realize these objectives, service providers use special routing protocols and techniques to manage user traffic more effectively. For example, ..
EIGRP allows for up to six equal-metric routes to be installed into the IP routing table at the same time. However, because of the complex EIGRP metric calculation, metrics may often be close to each other, but not exactly equal. To allow for metrics that are somewhat close in value to be considered equal, and added to the IP routing table, you can use the variance multiplier command. The multiplier defines a value that is multiplied by the lowest metric (in other words, the ..
BGP neighbor relationships, often called peering, are usually manually configured into routers by the network administrator, according to certain rules and to logically follow the overall network topology. Each neighbor session runs over TCP (port 179) to ensure reliable delivery and incremental, rather than periodic, rebroadcasting of updates. These two characteristics distinguish BGP from the auto-neighbor-discover/periodic-rebroadcast nature of most interior routing protoc..
Remote Authentication Dial-In User Service
RADIUS is a client/server-based system that secures a Cisco network against intruders. Implemented in Cisco IOS, RADIUS sends authentication requests to a RADIUS server. RADIUS was created by Livingston Enterprises and is now defined in RFCs 2865/2866 (RFCs 2138/2139 are now obsolete). A RADIUS server is a device that has the RADIUS daemon or application installed. RADIUS must be used with AAA to enable the authentication, authorization, and accounting of remote users when us..
You can use HSRP on a Token Ring LAN exactly the same if the only protocol on the segment is IP. However, if you have any other protocols, and particularly if the ring uses any source-route bridging, you must use a slightly different configuration: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)#interface Tokenring0 Router1(config-if)#ip address 172.22.1.3 Router1(config-if)#standby ip 172.22.1.1 Router1(con..
