Invalid MD5 digest - BGP Traffic Through Checkpoint

Tuesday, 30 June 2009 09:07

Firewalls - Checkpoint

Issue

When allowing eBGP traffic through a Checkpoint Firewall you may receive the following error message on your BGP peered routers. (This error may occur at the point of pushing a policy to your Checkpoint Firewall),

TCP-6-BADAUTH: Invalid MD5 digest from [Source IP]:[Source Port] to [Dest IP]:179

Solution

This is down to the Checkpoint State Table and the TCP sequence number of the BGP Traffic changing at the point of policy push.

To prevent this occurring you will need to change the following settings,

• Checkpoint Gateway Object > Advanced > Connection Persistence > (Tick) Keep all connections
• Services > TCP > BGP Service > (Tick) Keep connections open after Policy has been installed