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mikeyb
12-26-2011, 07:13 PM
at the top of page 492 in seventh edition it sez "that if EIGRP is still enabled on the routers, you will not see any OSPF routes"

But actually I do. Maybe I can get a comment on that: For example here's
2501A (although I named it differently)

O 172.16.30.1/32 [110/65] via 172.16.20.2, 00:11:40, Serial0/0
MIDDLE_BOTTOM#sh ip ro
Codes: C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, 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 not set
172.16.0.0/16 is variably subnetted, 7 subnets, 3 masks
D 172.16.50.0/24 [90/2809856] via 172.16.20.2, 00:48:52, Serial0/0
O 172.16.50.1/32 [110/129] via 172.16.20.2, 00:18:53, Serial0/0
D 172.16.40.0/30 [90/2681856] via 172.16.20.2, 00:50:02, Serial0/0
D 172.16.30.0/24 [90/2297856] via 172.16.20.2, 00:50:02, Serial0/0
O 172.16.30.1/32 [110/65] via 172.16.20.2, 00:18:53, Serial0/0
C 172.16.20.0/30 is directly connected, Serial0/0
C 172.16.10.0/24 is directly connected, FastEthernet0/0

and here's filtering the output:

MIDDLE_BOTTOM#sh ip ro os
172.16.0.0/16 is variably subnetted, 7 subnets, 3 masks
O 172.16.50.1/32 [110/129] via 172.16.20.2, 00:19:55, Serial0/0
O 172.16.30.1/32 [110/65] via 172.16.20.2, 00:19:56, Serial0/0
MIDDLE_BOTTOM#

the only thing I can see is the routes are installed because they are /32s

Thanks
ciscodaze
12-26-2011, 08:33 PM
the only thing I can see is the routes are installed because they are /32s

Thanks

Interesting, if you do a clear ip route * - which forces the routing table to rebuild - and you still see those routes, then you would have to be correct.

I'll see if I can do that up fast in PT.
ciscodaze
12-26-2011, 09:24 PM
I dont have the book Mikey, so I may be lacking details, but Im getting the same result.

I have a loopback of 172.16.50.1/32 and the other routing tables give me an OSPF and EIGRP route of /32 and /24, respectively (with eigrp auto-summary on, or off, same result). Both protocols ON at the same time.


I think you figured it out.
ciscodaze
12-26-2011, 09:51 PM
I dont have the book Mikey, so I may be lacking details, but Im getting the same result.

I have a loopback of 172.16.50.1/32 and the other routing tables give me an OSPF and EIGRP route of /32 and /24, respectively (with eigrp auto-summary on, or off, same result). Both protocols ON at the same time.


I think you figured it out.

whoops, my mistake. I mistakenly advertised 172.16.50.1 as a /24 for eigrp...once I changed it to /32, like the 172.16.50.1/32 for ospf, then turned off eigrp, ospf popped in (whereas it was not there before).

moral of the story: what you see in the routing table when running more than one protocol depends on the masks you use when doing your network statements (or, what gets advertised to that router from outside).

The reason I saw routes for both routing protocols the first time (maybe why you did too) is that they were both valid, with the ospf /32 being more specific. So they both get installed -- even though eigrp wins (normally) with the AD of 90, ospf got installed with it because it had a more specific route (longest match rule).

Once I gave them both /32, the AD tie-breaker kicked in and knocked ospf out, (until eigrp got turned off, allowing the ospf route to be installed as the best route).

edit: looking at your output, thats exactly what happened:

D 172.16.50.0/24 [90/2809856] via 172.16.20.2, 00:48:52, Serial0/0
O 172.16.50.1/32 [110/129] via 172.16.20.2, 00:18:53, Serial0/0