From: Earl Aboytes (earl@xxxxxxxxxxxx)
Date: Sun Jun 18 2000 - 04:53:13 GMT-3
Think of the access list that you need to use in the same way that you would
other access-lists. Since test frames are sent to the null sap you will
need to filter 0x0000. According to RFC 1795 Typical SAP values for SNA are
0x04, 0x08, and 0x0C. Since you need to consider the C/R and I/G bit you
will also need to worry about 0x01, 0x05, 0x09 and 0x0D.
Broken down to binary here are all of the byte values
0x00 0000 0000
0x01 0000 0001
0x04 0000 0100
0x05 0000 0101
0x08 0000 1000
0x09 0000 1001
0x0C 0000 1100
0x0D 0000 1101
If you look down each column you will notice that only three different
positions change value. Since the only values that change are in position
8, 4 and 1, and 1 is the don't care bit you place a 1 in the mask in those
same positions. This would be 0000 1101 or 0x0D. To match on all SNA frames
you need the following access list.
Access-list 201 permit 0x0000 0x0D0D
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Earl Aboytes
Senior Technical Conultant
GTE Managed Solutions
805-381-8817
earl.aboytes@telops.gte.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
kmiho@lycos.ne.jp
Sent: Friday, June 16, 2000 2:02 AM
To: ccielab@groupstudy.com
Subject: DLSW+ Frame Type
Hi all.
Read thru some DLSW+ and RSRB materials but still don't know how to
filter certain types of DLSW+ frames. Can someone give some guidance?
1)How do you filter the test frame and explorer packet?
2)Where can I find more info on the type of DLSW+ frames? I only
know some from Caslow's book, like F0 for Netbios and 04 for
SNA etc...
Thanks in advance.
Yours,
Kmiho
kmiho@lycos.ne.jp
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