RIP MD5 authentication

[jp]

Hi all,
I'm trying to use the RIP protocol of BIRD in MD5 authentication mode. I
use bird version 1.2.1.

While checking interoperability with quagga (i use for this the
zeroshell distribution running quagga ripd 0.98.4) md5 authentication
failed with the message:
"MD5 tail signature is not there".
I then used Wireshark to capture a rip response packet sent by bird and
found that the MD5 authentication data trailer starts with "FFFF 0100".
The same packet from quagga ripd starts with "FFFF 0001".
Looking in the RFC2082, the value from quagga seems to be the right one.

historically, the value "FFFF 0001" was used by bird but this was
changed to "FFFF 0100" in a patch resolving "RIP authentication problem
with cisco".

So can someone tell me was is the right value? 
Following RFC2082, it seems that we should use "FFFF 0001" but i don't
have cisco products and don't want to break cisco compatibility....

regards,
Jean PEREIRA