Getting this error after upgrading ASA to 8.3/8.4

[bechong]

successfully upgraded configs from old 5520 to 5525x by stepping through the code with one exception:  On boot this error appears:

Warning: 10.0.0.0-10.255.255.255 overlaps with failover interface address.  The failover units may become active.  Output from config line 1406, " nat (inside,DMZ1) static 10.0.0.0 no-proxy-arp route lookup"

Any guidance would be greatly appreciated.

[Jouni Forss]

Hi,

I imagine you have upgraded from 8.2 or before to the new software levels and the automatic migration of the NAT rules is now overlapping failover interface IP address/network configurations.

Might be possible to either clean up the NAT configurations or change the address range on the Failover link if possible.

- Jouni

[Network Specialist]

I have the same error message while upgrading from 8.3--->8.4

WARNING: 10.5.0.0-10.5.255.255 overlaps with failover interface address. The failover units may become active
*** Output from config line 1235, "nat (inside_fw1,outside)..."

Is this something that can be ignored or could have impact?

Thanks in advance!

[ALIAOF_]

It is always a good idea to use the failover link to a completely separate different network, looks like you are using the whole 10.0.0.0/8 for your LAN setup your failover to something like:

192.168.255.0/30