From: gladston@br.ibm.com
Date: Mon Nov 22 2004 - 13:23:40 GMT-3
This problem came when studying Doyle I, on the OSPF chapter that says we should add a route to null when performing IA summarization. I thought it had changed on new versions but the result I am getting is confusing. Sometimes the IOS adds automatically, sometimes it does not.
Any similar experience? The IOS is 12.2(1d).
r2#sir
172.16.0.0/16 is variably subnetted, 10 subnets, 3 masks
O 172.16.6.128/27 [110/11] via 172.16.26.6, 00:27:58, Ethernet0
O 172.16.6.32/27 [110/11] via 172.16.26.6, 00:27:58, Ethernet0
C 172.16.25.5/32 is directly connected, Serial1
C 172.16.25.0/24 is directly connected, Serial1
C 172.16.26.0/24 is directly connected, Ethernet0
C 172.16.23.0/24 is directly connected, Serial0.23
O 172.16.6.0/24 is a summary, 00:27:59, Null0
O 172.16.6.0/27 [110/11] via 172.16.26.6, 00:28:00, Ethernet0
C 172.16.2.0/24 is directly connected, Loopback0
O 172.16.6.64/27 [110/11] via 172.16.26.6, 00:28:00, Ethernet0
r2#
After no router ospf1, and configuring it again:
r2#sir os
172.16.0.0/16 is variably subnetted, 10 subnets, 4 masks
O 172.16.6.128/27 [110/11] via 172.16.26.6, 00:09:16, Ethernet0
O 172.16.6.32/27 [110/11] via 172.16.26.6, 00:09:16, Ethernet0
C 172.16.25.5/32 is directly connected, Serial1
C 172.16.25.0/24 is directly connected, Serial1
C 172.16.26.0/24 is directly connected, Ethernet0
C 172.16.23.0/24 is directly connected, Serial0.23
O 172.16.6.0/27 [110/11] via 172.16.26.6, 00:09:16, Ethernet0
C 172.16.2.0/24 is directly connected, Loopback0
O 172.16.6.64/27 [110/11] via 172.16.26.6, 00:09:17, Ethernet0
I tried to find any other point that could cause this behavior, with no success. The configuration is the same on both cases.
This is the configuration:
router ospf 1
log-adjacency-changes
area 1 range 172.16.6.0 255.255.255.0
network 172.16.25.0 0.0.0.255 area 0
network 172.16.26.0 0.0.0.255 area 1
This archive was generated by hypermail 2.1.4 : Thu Dec 02 2004 - 06:57:48 GMT-3