The maximum-paths Command and BGP Decision Process Tiebreakers
The goal of the BGP decision tree is to find the one best BGP route to each NLRI, from that router’s perspective. That router then considers only its best routes for advertising to other routers, restricting those routes based on AS_PATH loop prevention and routing policy configuration. That router also attempts to add that best route, and that best route only, to its IP routing table. In fact, as long as another routing source has not found a route to the same prefix, with..
Determining the Designated Router Using the priority Command
Remember that hello messages include a priority field and thus provide a mechanism by which the DR and BDR are elected. To be "up for election," the priority must be a positive integer between 1 and 255. If its priority is 0, the router cannot participate in the election. Otherwise, highest priority wins. All Cisco routers have a default priority of 1, and the highest router ID is used as a tiebreaker. As previously discussed in the "Electing DRs and BDRs" section, the comman..
Enhanced IGRP Classless Summarization
By default, Enhanced IGRP advertises at the natural classful network boundary for all the Enhanced IGRP internal routes. All external routes are not summarized when advertised across a major network. Before continuing with this discussion, you should understand the difference between internal and external routes in Enhanced IGRP. Internal routes are routes that are learned from the same autonomous number running on the local router. External routes are routes th..
Port-based authentication can be handled by one or more external Remote Authentication Dial-In User Service (RADIUS) servers. Although many Cisco switch platforms allow other authentication methods to be configured, only RADIUS is supported for 802.1x. The actual RADIUS authentication method must be configured first, followed by 802.1x, as shown in the following steps: Step 1. Enable AAA on the switch. By default, AAA is disabled. You can enable AAA for port-based aut..
The first step in configuring IP Mobility in your network is to set up one or more Home Agent routers, which will act as the virtual home base and support tunnels for your roaming devices: RouterHome#configure terminal Enter configuration commands, one per line. End with CNTL/Z. RouterHome(config)#interface Loopback0 RouterHome(config-if)#ip address 192.168.9.1 255.255.255.255 RouterHome(config-if)#exit RouterHome(config)#router mobile RouterHome(config-router)#e..
