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Wireshark-bugs: [Wireshark-bugs] [Bug 4551] New: "CISCO" Non-compliant with RFC-3411 bug for SNM

Date: Tue, 2 Mar 2010 17:03:48 -0800 (PST)
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=4551

           Summary: "CISCO" Non-compliant with RFC-3411 bug for SNMPv3
                    EngineID
           Product: Wireshark
           Version: 1.2.6
          Platform: Other
        OS/Version: All
            Status: NEW
          Severity: Trivial
          Priority: Low
         Component: Wireshark
        AssignedTo: wireshark-bugs@xxxxxxxxxxxxx
        ReportedBy: wbenton@xxxxxxxxxxxxxxxx


Created an attachment (id=4353)
 --> (https://bugs.wireshark.org/bugzilla/attachment.cgi?id=4353)
Packet Details. Look closely at Cisco's Engine ID and in particular their MAC
Address portion.

Build Information:
Version 1.2.6 (SVN Rev 31702)

Copyright 1998-2010 Gerald Combs <gerald@xxxxxxxxxxxxx> and contributors.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Compiled with GTK+ 2.18.5, with GLib 2.22.3, with WinPcap (version unknown),
with libz 1.2.3, without POSIX capabilities, without libpcre, with SMI 0.4.8,
with c-ares 1.7.0, with Lua 5.1, with GnuTLS 2.8.5, with Gcrypt 1.4.5, with MIT
Kerberos, with GeoIP, with PortAudio V19-devel (built Jan 27 2010), with
AirPcap.

Running on Windows XP Service Pack 3, build 2600, with WinPcap version 4.1.1
(packet.dll version 4.1.0.1753), based on libpcap version 1.0 branch 1_0_rel0b
(20091008), GnuTLS 2.8.5, Gcrypt 1.4.5, without AirPcap.

Built using Microsoft Visual C++ 9.0 build 30729

Wireshark is Open Source Software released under the GNU General Public
License.

Check the man page and http://www.wireshark.org for more information.
--
The EngineID which Cisco uses is non-compliant with RFC-3411 and they admit it.

See: https://supportforums.cisco.com/message/3010617#3010617 for details.

The part which they're non-compliant is that they add an additional byte just
before the MAC address making it look like there's a 4 byte MAC address rather
than a 3 byte one.

Wireshark diagnoses the Engine ID Format: MAC Address (3), but below that like
is a Wireshark added comment <Data not conforming to RFC3411> which is correct.

However, as Cisco is quite widely used, the question I ask is whether Wireshark
should be modified to display Cisco's proprietary information or just leave it
as <Data not conforming to RFC3411>.

Details of how Cisco uses that additional byte are mentioned in the above URL.

If Wireshark does NOT plan on adding this "Cisco specific" change, then please
close this out as a bug as it's really not a bug issue at all.

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