Cisco Systems CL-28826-01 EIGRP Routing on Cisco IOS Routers

64-8
User Guide for Cisco Security Manager 4.4
OL-28826-01
Chapter 64 Configuring Routing Policies
EIGRP Routing on Cisco IOS Routers
Field Reference
EIGRP Routing on Cisco IOS Routers
Enhanced Interior Gateway Routing Protocol (EIGRP) is an enhanced distance vector protocol
developed by Cisco Systems that integrates the capabilities of link-state protocols. EIGRP is suited for
many different topologies and media. Key capabilities that distinguish EIGRP from other routing
protocols are fast convergence, support for variable-length subnet masks, partial updates, and multiple
network-layer protocols.
The metric that the router uses to reach the destination, and to advertise to other routers, is the sum of
the best-advertised metrics from all neighbors and the link cost to the best neighbor.
EIGRP uses neighbor tables to store address and interface information about each of the router’s
neighbors. Hello packets advertise hold times, which is the length of time a neighbor can be considered
reachable and operational. Topology tables contain all destinations advertised by neighboring routers.
For each neighbor, the entry records the advertised metric, which the neighbor stores in its routing table.
Table64-4 BGP Redistribution Mapping Dialog Box
Element Description
Protocol to Redistribute The routing protocol that is being redistributed:
•Static—Redistributes IP or OSI static routes. You can define a
single mapping for each route.
•EIGRP—Redistributes an EIGRP autonomous system. Enter the
AS number in the displayed field. You can define a single mapping
for each AS.
•RIP—Redistributes RIP routes. You can define a single mapping
for each route.
•OSPF—Redistributes a different OSPF process. You can define a
single mapping for each process. Select a process from the
displayed list, then select one or more match criteria:
– Internal—Routes that are internal to a specific AS.
– External1—Routes that are external to the AS and imported
into OSPF as a Type 1 external route.
– External2—Routes that are external to the AS and imported
into the selected process as a Type 2 external route.
– NSAAExternal1—Not-So-Stubby Area (NSSA) routes that
are external to the AS and imported into the selected process
as Type 1 external routes.
– NSAAExternal2—(NSSA) routes that are external to the AS
and imported into the selected process as Type 2 external
routes.
•Connected—Redistributes routes that are established
automatically by virtue of having enabled IP on an interface. These
routes are redistributed as external to the AS.
Metric A value representing the cost of the redistributed route. Valid values
range from 0 to 4294967295.