topic Re: Problem with OSPF ECMP in Switches, Hubs, and Modems

Problem with OSPF ECMP

Carlos Jorge Santos — Sun, 13 Mar 2011 02:46:29 GMT

Hi all,

I'm using some Procurve 3400cl 48G as my TOR switch along with some cisco 3550.

I'm getting the default routes from two core foundry's announcing via OSPF.

This is working great in Cisco and not that great in HP.

In cisco i have two default routes (0.0.0.0) received by ospf and in HP only one default route is received.

If i kill the interface announcing this default route, the other one is active and both default routes should be active. ECMP is active by default on this switch.

Can someone point me some directions ?

Thanks
Carlos

Re: Problem with OSPF ECMP

Carlos Jorge Santos — Tue, 15 Mar 2011 09:36:52 GMT

Hello again,

Anyone ? How can i get this switch to have two default gateways annouced by OSPF and used them ?

Right now he's only using one at the time.

"ip load-sharing" is active and with value "4" by default.

Thanks you
Carlos Santos

Re: Problem with OSPF ECMP

Mohammed Faiz — Wed, 16 Mar 2011 10:13:34 GMT

Sounds odd.
Could you post up the output of "sh ip route" and "sh ip ospf area"?

Re: Problem with OSPF ECMP

Carlos Jorge Santos — Wed, 16 Mar 2011 18:54:12 GMT

Hello,

Rack B5# sh ip ospf area

OSPF Area Information

Area ID Type Cost SPFR ABR ASBR LSA Checksum
--------------- ------ ----- ------ ---- ---- ----- ----------
0.0.0.1 normal 1 543 2 6 56 0x001a687a

Rack B5# sh ip route

IP Route Entries

Destination Gateway VLAN Type Sub-Type Metric Dist.
------------------ --------------- ---- --------- ---------- ---------- -----
0.0.0.0/0 xx.xx.172.161 123 ospf External2 10 110
xx.xx.0.20/30 xx.xx.172.161 123 ospf External2 10 110
xx.xx.0.120/30 xx.xx.172.161 123 ospf InterArea 3 110
xx.xx.47.0/24 xx.xx.172.161 123 ospf InterArea 3 110
xx.xx.168.0/27 xx.xx.172.161 123 ospf InterArea 14 110
xx.xx.168.32/30 xx.xx.172.161 123 ospf InterArea 4 110
xx.xx.168.40/29 xx.xx.172.161 123 ospf InterArea 4 110
xx.xx.168.48/29 xx.xx.172.161 123 ospf InterArea 4 110
xx.xx.168.56/29 xx.xx.172.161 123 ospf InterArea 4 110
xx.xx.168.64/28 xx.xx.172.161 123 ospf InterArea 4 110
xx.xx.168.80/29 xx.xx.172.161 123 ospf InterArea 4 110
xx.xx.168.88/29 xx.xx.172.161 123 ospf InterArea 4 110
xx.xx.172.156/30 Uplink CR1 122 connected 0 0
xx.xx.172.160/30 Uplink CR2 123 connected 0 0
xx.xx.172.108/30 xx.xx.172.157 122 ospf IntraArea 2 110
xx.xx.172.116/30 xx.xx.172.157 122 ospf IntraArea 2 110

This list goes on, the main thing here is only one default route is active

If you need something else, just ask.

Thank you for your time
Carlos Santos

Re: Problem with OSPF ECMP

Mohammed Faiz — Thu, 17 Mar 2011 12:50:25 GMT

Ok, would you be able to post the same ip route output for when the currently used interface is disabled?
Could you also grab the output (with both interfaces up) of "sh ip ospf nei", "show ip ospf external" and "sh ip ospf interface".

Re: Problem with OSPF ECMP

Carlos Jorge Santos — Thu, 17 Mar 2011 17:18:40 GMT

Dear Mohammed Faiz,

Thank you for your time, I've replaced the HP switches and everything is working as supposed.

Again, thank you for trying to help me.
Carlos Santos