Tunnel GRE - NAT Debugging

[sergio.paganoni]

Hi,

I've noticed on a Cisco Router 2801 (with IOS ver. 12.4(15)T1) something strange debugging ip nat (#debug ip nat).

Feb 2 13:38:43.576: NAT*: GRE port: 1709637020 - [34077]

Feb 2 13:38:43.576: NAT*: GRE port: 1709637020 - [34078]

Feb 2 13:38:43.708: NAT*: GRE port: 1709637020 - [34079]

Feb 2 13:38:43.712: NAT*: GRE port: 1709637020 - [34080]

......etc....etc....

This message occurrs hundreds of times (as you can see from the time delay between each one)

I've a GRE tunnel who works fine on it (status ACTIVE and traffic flows in and out correctly), I'd just ask if someone could explain me this kind of debug message.

I was just asking myself why I've so much NAT entries (considering poor traffic flow).

Thanks for the attention.

Sergio Paganoni

[Giuseppe Larosa]

Hello Sergio,

GRE has not port or socket concept and the number 1709637020 is really too high.

see for GRE header

http://www.faqs.org/rfcs/rfc2784.html

Have you configured some form of NAT over the GRE tunnel ?

if not this is really noise

Hope to help

Giuseppe