ACL's on Firewall IOS

[alburton]

I have a 2600 router with IOS Software (C2600-IK8O3S-M), Version 12.2(5d). On an extented named ACL with the following entries

permit tcp host 192.168.1.10 10.1.2.224 0.0.0.30 eq 1494

permit udp host 192.168.1.10 10.1.2.224 0.0.0.30 eq 1604

This was causing connection to connections to 10.1.2.227 to be blocked, so when the ACL was expanded to

permit tcp host 192.168.1.10 10.1.2.224 0.0.0.31 eq 1494

permit udp host 192.168.1.10 10.1.2.224 0.0.0.31 eq 1604

The connections worked.

Does anyone know a reason for this.

Thanks..

[nsteup]

Hello Alan,

your wildcardmask .30 looks 00011110 in binary. This is not allowed because when you set one bit to 1 all following bits must be set to 1s either. So the .31 wildcardmask looks 00011111 in binary and that is allowed and - as you say - it works.

Best regards

Norbert