Hi All,

My current configuration is (Cisco IOS Router <--> Cisco ASA Firewall <--> Mikrotik Router) this all currently works well with IPv4, I have IPv6 connectivity from the Cisco ASA's WAN interface outbound but I'm unable to ping between the Mikrotik to the ASA when I do I get a strange issue show my IPv6 address as the replying one and not the ASA.

The ASA IPv6 address is 2a02:8011:8003:1:: and the Connected Mikrotik is 2a02:8011:8003:1::1

Can anyone see anything ovious.

You can't use if netmask is /64 then you cannot use 2a02:8011:8003:1::, it is a network address for this subnet.

Thanks, I came to the same conclusion last night and changed the address to 2a02:8011:8003:1::1 and 2a02:8011:8003:1::2 and now I can communicate between them

Thanks for replying