Dynamic PAT and Static NAT issue ASA 5515

Question

Hi All,
Recently we migrated our network to ASA 5515, since we had configured nat pool overload on our existing router the users are able to translated their ip's outside. Right now my issue was when I use the existing NAT configured to our router into firewall, it seems that the translation was not successful actually I used Dynamic NAT. When I use the Dynamic PAT(Hide) all users are able to translated to the said public IP's. I know that PAT is Port address translation but when I use static nat for specific server. The Static NAT was not able to translated. Can anyone explain if there's any conflict whit PAT to Static NAT? I appriciate their response. Thanks!
- Bhal

Answer 1

Hi,
I would have to guess that you Dynamic PAT was perhaps configured as a Section 1 rule and Static NAT configured as Section 2 rule which would mean that the Dynamic PAT rule would always override the Static NAT for the said host.
The very basic configured for Static NAT and Default PAT I would do in the following way
object network STATIC
host
nat (inside,outside) static dns
object-group network DEFAULT-PAT-SOURCE
network-object
nat (inside,outside) after-auto source dynamic DEFAULT-PAT-SOURCE interface
The Static NAT would be configured as Network Object NAT (Section 2) and the Default PAT would be configured with Twice NAT / Manual NAT (after-auto specifies it as Section 3 rule)
This might sound confusing. Though it would be easier to say what the problem is if we saw the actual NAT configuration. Though I gave the reason that I think is probably one of the most likely reasons if there is some conflict with the 2 NAT rules
You can also check out a NAT document I made regarding the new NAT configuration format and its operation.
https://supportforums.cisco.com/docs/DOC-31116
Hope this helps
- Jouni