Passing GRE Traffiс through NAT

Globba — Fri, 11 Nov 2022 17:13:00 GMT

I have 2 Cisco routers - one in the branch office (37.17.104.38) and one in the main office (10.13.80.1) - see attached picture sceme.jpg

The router in the main office stands behind the CheckPoint Firewall R81.10.

I need to establish GRE Tunnel between this two routers so I'm trying to make NAT rule on the Firewall which will redirect incoming GRE traffic to firewall (interface 212.98.191.216) to 10.13.80.1 (the routers interface).

So I created the NAT rule (see attached error.jpg):

- Original Source : 37.17.104.38

- Original Destination: 212.98.191.216

- Original Services: GRE

- Translated Source: original

- Translated Destination: 10.13.80.1

- Translated Services: original

But in verification window appears error - "Field Original Services references invalid oblects". This message disappears only when I

delete GRE from Original Services.

What is wrong?

Re: Passing GRE Traffiс through NAT

PhoneBoy — Sat, 12 Nov 2022 14:20:24 GMT

If you wish to NAT GRE traffic, or any other non-TCP/UDP traffic for that matter, you must use the service "Any".
Only TCP/UDP services can be used in the NAT rulebase.

topic Re: Passing GRE Traffiс through NAT in Firewall and Security Management

Passing GRE Traffiс through NAT

Re: Passing GRE Traffiс through NAT