Distance-Vector Protocols
45
Invalid timers These specify how long a router should wait before
declaring a route invalid if it doesn't receive a specific update about it. The
default is three times the update period.
Hold-down timers These specify the hold-down period. The default is
three times the update timer period plus 10 seconds.
Flush timers These indicate how much time should pass before a route
should be flushed from the routing table. The default is seven times the
routing update period.
Verifying IGRP
The output below is from an IGRP router:
2621A#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP,
M [output cut]
T - traffic engineered route
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 5 subnets
I 172.16.50.0 [100/160360] via 172.16.10.2,
FastEthernet0/0
I 172.16.40.0 [100/160260] via 172.16.10.2,
FastEthernet0/0
I 172.16.30.0 [100/158360] via 172.16.10.2,
FastEthernet0/0
I 172.16.20.0 [100/158260] via 172.16.10.2,
FastEthernet0/0
C 172.16.10.0 is directly connected, FastEthernet0/0
The I means IGRP-injected routes. The [100/160360] is the administra-
tive distance of IGRP and the composite metric. The lower the composite
metric, the better the route.
Copyright ©2001 SYBEX , Inc., Alameda, CA
www.sybex.com