I have a problem with ASDM of two ASA 5520 when these are working with failover because if the primary is active and the secondary is passive, I can't access with ASDM while if the primary is passive and the secondary is active I can access with ASDM, it's worth noting that both have images asdm-625-53 and asa823-k8. Please if someone knows what is the cause of this behavior help me. Thank you
That means that you can access the device via SSH or telnet? And that also you can ping it? Would you please collect the debug HTTP that Panos asked you? Also, would you please paste the output of the show asp table socket?
Double check the output of 'show ver', 'show flash', and 'show run asdm' to make sure that the output matches on both units. You should see the image located on the flash of both units and the 'asdm image' command should be set on both.
This document should also help with troubleshooting:
Also what you can try is to check if you have any routing protocols running on the devices, the routing table is not replicated to the standby unit, therefore you will not be able to reach it, you can add static routes as a workaround for this problem.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...