Ace 4710 strange behaviour

Question

Hi, We have two ACE-4710-K9 (named LB01 and LB02) configured in HA mode. Besides Admin, on each of them there are tree context configured, named, ACADEMIC, COMMERCIAL, STREAMING. On LB01 the active context is ACADEMIC. On LB02 the active contexts are COMMERCIAL and STREAMING. Each context is configured with a FrontEnd and a BackEnd Vlan interface, and a "management" Vlan interface used for accessing and monitoring the device and for the downloading of the needed ssl certificates. Recently we upgraded the devices to Version A3(2.6) form a previous A3(2.4). After that upgrade we experienced some strange behaviour. From the context in STANDBY state we are not able to ping the host on the "management" Vlan interface, while there is no problem on the other Vlans. We see that the ICMP packets are sent to the Vlan, are replayed by the remote host BUT are not received at all on the LB01 or LB02. No messages in the log. Trying with 5 consecutive (failed) ping we can see that the counters of unicast packet output on LB01/LB02 Vlan is incremented by 5 BUT the unicast packets input counters is unchanged even if the remote host sent the replays. In the STREAMING context this behaviour isn't constant, ie the ping *sometimes* starts working for a few second and then returns to stop. In the other standby context the ping never works instead. In the active context all works fine. This strange problem prevents us to load the ssl certificates in the STANDBY context from the "management" Vlan. We was not able to find any reference to a similar problem in the Cisco documentation or Tac collection, so we are curious to know wheter someone else experienced such a behaviour. Thank you and best regards. Alessandro Asson - CINECA

Answer 1

Thanks,
I see you are using shared VLAN config in both ACE.
Same VLAN 1000 is used for both Admin and streaming context.
In this config, you may need to use the shared-vlan-host-id command as explained here:
http://www.cisco.com/en/US/docs/app_ntwk_services/data_center_app_services/ace_appliances/vA3_1_0/configuration/routing_bridging/guide/vlansif.html#wp1025243
In fact as explained:
'By default, the bank of MAC addresses that the ACE uses is randomly selected at boot time. However, if you configure two ACE appliances in the same Layer 2 network and they are using shared VLANs, the ACEs may select the same address bank, which results in the use of the same MAC addresses. To avoid this conflict, you must configure the bank that the ACEs will use.'
This would also reply to your question in the readme file:
SHOW ARP TABLE ON THE D01,D02,D07 ROUTERS SHOWS THE SAME MAC ADDRESS FOR
BOTH IP ADDRESSES OF LB01 AND LB02: is that normal ??
Hope this helps,
Dom.