topic Re: Destination NAT issue or routing change in General Topics

Destination NAT issue or routing change

a.jones — Thu, 02 Jul 2020 13:50:48 GMT

Hi All,

I have had a destination nat running for months without issue.

NAT: Source VPN Interface to Inside Interface: Destination Address: 192.168.90.231 Destination Translation: 10.0.8.82

Rule: Source VPN to Inside : Source IP to 192.168.90.231

It has been working for months without issue.

Suddenly last night, the traffic to 192.168.90.231 starts routing to the outside interface and NAT stops working as traffic isn't heading that way. No changes were made on the system, it's not in the BGP routing table. As there is no rule for this it hits default deny. I have checked that the destination real address is routable and it is.

This is the only path that is failing. Any idea's?

Regards

Adrian

Re: Destination NAT issue or routing change

SutareMayur — Fri, 03 Jul 2020 11:46:32 GMT

@a.jones,

I think, there are some changes happened w.r.t. routing for IP 192.168.90.231 and due which traffic is routed outside interface. You can also verify your device FIB to see active routes. Also verify same using test commands through cli.

Mayur

Re: Destination NAT issue or routing change

a.jones — Thu, 16 Jul 2020 12:00:43 GMT

That range was only ever used as an IP range for receiving traffic on the firewall to translate to a real IP on the network. Not sure why it occurred, we think it must have existed somewhere on the internal network and we were lucky before that it worked.

I added a static NAT and that resolved the issue.

Regards

Adrian