Stefan,
For one reason or another I created the custom service Netbios for Netbios(NS). Wait, now I recall, although the firewall will detect and block 'Netscreen (NS)' packets, there doesn't seem to be a correlating predefined entry to allow for it when making a policy. Anyway, the service is setup as:
Netbios TCP src port: 0-65535, dst port: 137-137 30 Edit Remove
As you can see, the timeout is 30 minutes, yet in my firewall I constantly see:
2008-01-29 16:34:42 172.31.202.4:34113 10.200.1.2:137 172.31.202.4:34113 10.200.1.2:137 NETBIOS (NS) 60 sec. 96 102 Close - AGE OUT
2008-01-29 16:34:26 172.31.202.4:34112 10.200.1.2:137 172.31.202.4:34112 10.200.1.2:137 NETBIOS (NS) 59 sec. 96 102 Close - AGE OUT
So I went looking for a reason, since these sessions should not 'age out' at around the 60 second marker. Is there something behind the scenes that I am missing??