How to Block Netbios

Unanswered Question
Aug 5th, 2010

I have cisco 1800 series router and i want to block Netbios on that.

I have this problem too.
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Jayakrishna Mada Thu, 08/05/2010 - 23:49

Hi Prasad,

Do you have ip helper addess configured on the switch if yes then configure

no ip forward-protocol udp 137
no ip forward-protocol udp 138
no ip forward-protocol udp 139

if not you can configure and apply this access-list:

access-list 110 deny   tcp any any range 137 139

access-list 110 deny   udp any any eq netbios-ss

access-list 110 deny   udp any any eq netbios-dgm

Hope this helps.


PRASAD BAIT Mon, 08/09/2010 - 06:10

Hi Jayakrishna,

thanks for your support.

But plz tell me that is there any need to configure the ip helper address or not???


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