Re: Filters 102

Dan Pritts (danno@aa.fv.com)
Mon, 4 Aug 1997 21:15:31 -0400 (EDT)

On Mon, 4 Aug 1997, E Kelly Bond wrote:
> >sho filter filter1.out
>
> 1 deny 0.0.0.0/0 0.0.0.0/0 udp dst eq 137 log
> 2 deny 0.0.0.0/0 0.0.0.0/0 udp dst eq 138 log
>
> eliminate the possiblilty of netbeui garbage being sent out
> onto the net from the portmaster by blocking udp/138 and
> udp/138 from leaving the portmaster.

I don't know PM filter syntax well enough to know whether this is the
correct syntax to do what you say you want, but just to be pedantic...

NetBEUI isn't a TCP/IP protocol; it's a different network protocol
entirely. SMB (microsoft lanman/nt networking), which uses netbeui,
can also use TCP/IP. When it does so, it uses the NetBIOS port
numbers, which are 137-9.

I believe you would also (instead?) have to deny TCP ports 137/138
and also UDP&TCP 139 to do what you want.

dan pritts
Unix System Admin First Virtual Holdings, Inc.
danno@aa.fv.com 313-213-3791