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genseek_32178
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Feb 19, 2013

LTM Bug/Known Issue

Hi,

 

We have LTM 8900 boxes in production with many VLANs. We keep extending new VLANs to the boxes every nw and then as per request.

 

And BTW, the boxes are deployed in HA pair, A and B.

 

LTM boxes are connected to L2AGG switch which is inturn connected to upstream L3 router, also, in HA pair.

 

As part of extending VLANs, we create self and floating IP on both LTM boxes of the HA pair.

 

Recently, we have seen that after creating self IPs, when we try to ping L3 router A and B IPs for that VLAN,

 

we cannnot ping from LTM B box to L3 Router B VLAN IP, nor can we ping between LTMs on the same VLAN.

 

This has been seen in instances of creating new VLANs on the LTM boxes. Is this behaviour related to ANY bug?

 

We are running 10.2.1

 

thanks- genseek

 

 

 

4 Replies

  • I'm not aware of any bugs (which doesn't mean there are not).

     

     

    1) Does the issue ever resolve itself?

     

    2) Do you manually create the VLAN on both BIG-IPs and add it to the relevant interfaces?

     

    3) Is STP involved? If so, have you checked to see if the LTM B interface is the one that is blocked?

     

    4) You can't PING but do you see an ARP entry?

     

    5) Are there any interswitch links that are perhaps not allowing the new VLAN, or are not being configured when new VLANs are created?
  • Please see replies as below

     

     

    1) Issue resolves when we do bigstart restart, seen in couple of cases.

     

     

    2) Yes

     

     

    3) Yes, LTM B interface is not blocked.

     

     

    4) In some cases ARP is seen on l3 router and not in otjhers.

     

     

    5) VLANs are allowed on inter switch links.
  • Funnily enough this is starting to bring back memories from when I used to run v10. I can't quite remember what the workaround was but it was one of these two;

     

     

    1) Saving the config and then reloading it (non impacting I believe)

     

    2) If the above doesn't work your only option is bigstart but you can minimise the impact by just restarting the network service
  • How is your network setup? Router on a stick? Are you routing your routers down to your switches? (ie OSPF, EIGRP) You state "L3 Routers"... so is your L3 on the routers or the switches? When you perform a "show spanning-tree vlan X" on your switches... where is your root bridge? If anything, you should be able to see your LTM interfaces on the arp table of the L3. Whether it is Active or Standby. If you do not, you may have a routing issue and not a v10 bug.