ospf-redistribute

[Shibu1978]

Hi,

Recently we added a cisco 4948 switch to our existing network and static redistribute one of its vlan ( 10.30.1.0/24) to the OSPF domain. This switch is being connected only to C4506-Main.  Now 10.30.1.0/24 network reach 10.203.206.40 at other end.  Everything is perfect and working well with Main STM-16 link.

Few clarification needed.

1) When Main STM-16 link fails & traffic shifted to Backup STM-16  communication stop from 10.30.1.0/24 to 10.203.206.40. we had to manually remove the redistribute command from C4506-Main and apply to C4506-Backup to regain the access. Even the metric-type 1 was not working and we had to change to  redistribute static metric 29 subnets route-map OTT.

Is there any other way we can make it work the redistribution? may be automatically?  why Same metric-type 1 was not working with other switch ?

Please find  the digram and configs.

C4506-Main

==========

Router ospf 10

redistribute static metric-type 1 subnets route-map OTT

ip route 10.30.1.0 255.255.255.0 10.30.255.18

ip access-list extended OTT

permit ip 10.30.1.0 0.0.0.255 any

C4506-Backup

============

router ospf 10

ip route 10.30.1.0 255.255.255.0 10.20.2.230 name to C4506-Main

[blau grana]

Hello,

- does 4948 run OSPF?

- is entire topology in one area?

Can you provide full OSPF configuration from Main and Backup switch?

show run | section router ospf

Best Regards

Please rate all helpful posts and close solved questions

[Shibu1978]

- does 4948 run OSPF?

No

- is entire topology in one area?

Single area only . Area0

Can you provide full OSPF configuration from Main and Backup switch?

C4506-Main

==========

router ospf 10

router-id 10.10.1.2

log-adjacency-changes

redistribute static metric-type 1 subnets route-map OTT

network 10.10.1.2 0.0.0.0 area 0

network 10.20.2.0 0.0.0.255 area 0

interface Vlan200

ip address 10.20.2.230 255.255.255.0

standby 200 ip 10.20.2.254

standby 200 priority 110

standby 200 preempt

ip route 10.30.1.0 255.255.255.0 10.30.255.18 name C4948

ip access-list extended OTT

permit ip 10.30.1.0 0.0.0.255 any

C4506-Backup

router ospf 10

router-id 10.10.1.3

network 10.10.1.3 0.0.0.0 area 0

network 10.20.2.0 0.0.0.255 area 0

interface Vlan200

ip address 10.20.2.231 255.255.255.0

standby 200 ip 10.20.2.254

standby 200 preempt

ip route 10.30.1.0 255.255.255.0 10.20.2.230 name to C4506-Main

ip access-list extended OTT

permit ip 10.30.1.0 0.0.0.255 any

[blau grana]

Hello Shibu

Add this commands on Main Switch:

router ospf 10

   network 10.30.255.0 0.0.0.255 area 0

   passive-interface INTERFACE_to_4948

Everything else seems OK. You have configured static route to 10.30.1.0/24 with next hop 10.30.255.18 but OSPF domain do no know about this network (10.30.255.0/24).

Try this modification and let us now if it helped.

Best Regards

Please rate all helpful posts and close solved questions

[Shibu1978]

Hi Grana,

Thanks for the inputs.

kindly clarrify

Current situation

============

On the current setup & configurations network 10.30.1.0/24 can access IP 10.203.206.40 through the STM-16 Main link.

Issue

=====

When the STM-16 Main link fails whole trafic will shift to STM-16 backup link except traffic from 10.30.1.0/24 to 10.203.206.40. We used to manually remove the redistribute command from C4506-Main and apply to C4506-Backup to regain the access. even we had to change the Metric-type 1 to metric2 .

Now with the suggested workaround hope i dont want to do the above exercise when STM-16 main link fails.

  router ospf 10

   network 10.30.255.0 0.0.0.255 area 0

   passive-interface INTERFACE_to_4948

Please clarrify..thanks for your input.

[paul driver · Accepted solution]

Hello

There should be no need to remove the redistribute static from the main router? If all devices are running on the backbone area 0 and all the routes are intra-area routes ( apart from the residistubeted E1/2) then  you should have resiliency.

The problem is you  haven't advertised the lan segment for  the C4506-Main and the cisco switch = 10.30.255.0/24

Blau as stated this in his post.

res

Paul

Please don't forget to rate any posts that have been helpful.

Thanks.

[blau grana · Accepted solution]

Hello Shibu,

As pdriver said, after you include link between Main and 4948 into OSPF, everything should be working fine. But to be sure can you also upload OSPF configuration of NE-80-1, NE-80-2 and routing table from 4948, thanks.

Best Regards

Please rate all helpful posts and close solved questions

[Shibu1978]

Thanks to all.

Will try the above option and let you know the outcome.

Thanks agian

Shibu

[paul driver]

Hello,

Do you have cisco 4948 switch running  ospf?
Looks like all the other devices in this topology are, so I dont think there would be a need to redistribute this network, just advertise it.

Even if you are  redistributing  from another routing protocol or staitc -C4506-Main should receive this route and/or advertise it to all other C4506-backup, NE80-1, NE80-2 and as you have defined best path via ospf cost , it the main connection drops then the backup path will be used.

I am assuming the C4506-backup is traversing the C4506-Main to get to 10.203.206.40

Regards you topology diagram cisco 4948 has no other redundant path so if  C4506-Main goes down then it will be isolated.

res

Paul

Please don't forget to rate any posts that have been helpful.

Thanks.