BGP-learned defaults are injected into EIGRP via redistribution. The 0/0 metric needs to be converted into an EIGRP-compatible metric by using the default-metric router subcommand. The configuration for RTA in Example 12-51 will inject its default with a high metric in such a way that the internal router (RTG) always gets a lower metric via RTF. Example 12-51. Using EIGRP as the IGP: RTA Configuration router eigrp 1 redistribute bgp 3 route-map DEFAULT_ONLY passive-interfac..
Preventing Suboptimal Routes by Setting the Administrative Distance
One simple and elegant solution to the problem of suboptimal routes on redistributing routers isto flag the redistributed routes with a higher AD. A route’s AD is not advertised by the routingprotocol; however, a single router can be configured such that it assigns different AD values todifferent routes, which then impacts that one router’s choice of which routes end up in that router’srouting table. For example, back in Figure 11-4 and Example 11-3, R3 could have assig..
All the options for IP forwarding (routing) in this chapter had one thing in common: The destination IP address in the packet header was the only thing in the packet that was used to determine how the packet was forwarded. Policy routing allows a router to make routing decisions based on information besides the destination IP address. Policy routing’s logic begins with the ip policy command on an interface. This command tells IOS to process incoming packets with different l..
Multicast Addresses for Permanent Groups
IANA has reserved two ranges of permanent multicast IP addresses. The main distinction between these two ranges of addresses is that the first range is used for packets that should not be forwarded by routers, and the second group is used when packets should be forwarded by routers. The range of addresses used for local (not routed) purposes is 224.0.0.0 through 224.0.0.255. These addresses should be somewhat familiar from the routing protocol discussions earlier in the boo..
Using Route Maps to Refine Static Translation Rules
One of the best uses of this feature appears when you have two Internet Provider connections and you want to use distinct NAT rules for each: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#interface FastEthernet0/0 Router(config-if)#ip address 172.16.1.5 255.255.255.252 Router(config-if)#ip nat outside Router(config-if)#exit Router(config)#interface FastEthernet0/1 Router(config-if)#ip address 172.16.2.5 25..
