Wireshark · Ethereal-users: [Ethereal-users] BUG: 802.1ab (a.k.a LLDP) - Chassis ID TLV = IP Address

["STAN Knap" <sknap1@xxxxxxxxxx>]

Title: BUG: 802.1ab (a.k.a LLDP) - Chassis ID TLV = IP Address

Hello,

Today I tried the latest version of Ethereal. I think it is great.
However, it has a problem with decoding LLDP frames transmitted by Nortel phones.
Namely, it considers the phone's Chassis ID TLV invalid and stops decoding the
rest of the frame. Since the Chassis ID TLV is the first in the frame, no useful
decoding is generated.

In case of the phone, the Chassis ID TLV contains the phone's IP address.
Ethereal assumes that the length of such a TLV should be 5 and not 6
and stops decoding the frame.

I think that the Ethereal designers did not take into account the fact that in the Chassis TLV
IP address (4bytes) should be preceded by one byte indicating a particular network family.

The phone transmits the Chassis TLV as follows:

Length = 6
Chassis Subtype=5 [IP address]
Chassis ID = The telephone's IP address (4 bytes) preceded with 1 byte indicating a particular network address
family (IPv4=1).

Could you redirect this email to the right person ?
Thanks

Stan Knap
Nortel, Belleville, Ontario, Canada
Tel. 613 967 5258