12-16-2010 01:49 AM - edited 03-04-2019 10:48 AM
Hello,
I have a 3620 running the below IOS and a 2m line. When the 2m line fails the ISDN comes up, but routing doesn't fully work. Even though there is a 0.0.0.0/0 route, until I manually configure a 10.0.0.0 255.0.0.0 floating static, routing fails to work correctly.
IOS: c3620-js-mz.122-6c.bin
interface Dialer1
ip address 10.12.0.22 255.255.255.252
HAYDEP_D_CR362_01#sh ip ro
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is 10.12.0.21 to network 0.0.0.0
10.0.0.0/8 is variably subnetted, 6 subnets, 5 masks
C 10.12.3.0/24 is directly connected, FastEthernet0/0
S 10.0.0.0/8 [180/0] via 10.12.0.21
C 10.24.2.0/24 is directly connected, FastEthernet0/0
C 10.12.0.20/30 is directly connected, Dialer1
C 10.12.0.21/32 is directly connected, Dialer1
C 10.38.0.0/20 is directly connected, Loopback0
S* 0.0.0.0/0 [180/0] via 10.12.0.21
HAYDEP_D_CR362_01#sh run | in ip route
ip route 0.0.0.0 0.0.0.0 10.12.0.21 180
ip route 10.0.0.0 255.0.0.0 10.12.0.21 180 <<<<<<<<< routing doesn't work until this is added
Is this a known IOS problem and a quick upgrade will fix?
Thanks
Phil
Solved! Go to Solution.
12-16-2010 03:25 AM
Phil,
Do you perhaps see the command no ip classless in your configuration? Some of the symptoms you describe remind me of a classful routing behavior. If so, entering the ip classless command in your configuration should activate the "normal" classless routing behavior that we all know and use today.
You may be interested in reading more about the classful routing behavior here:
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094823.shtml#forwarding
Best regards,
Peter
12-16-2010 03:12 AM
Hi,
when you remove your floating static route to 10.0.0.0 is your static default in your routing table and if so
can you do a debug ip packet
Regards.
Alain.
12-16-2010 03:25 AM
Phil,
Do you perhaps see the command no ip classless in your configuration? Some of the symptoms you describe remind me of a classful routing behavior. If so, entering the ip classless command in your configuration should activate the "normal" classless routing behavior that we all know and use today.
You may be interested in reading more about the classful routing behavior here:
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094823.shtml#forwarding
Best regards,
Peter
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