[Olsr-dev] IP TTL value

Teco Boot (spam-protected)
Wed Jan 26 08:30:07 CET 2011


I have a second thought on to_be_used IP TTL value. RFC5082 "Generalized 
TTL Security Mechanism (GTSM)" proposes TTL=255 on sending, and check 
on 255 on reception. It was designed for BGP, but it is also used on 
IGPs. So we have options:
 - Leave as it is.
 - Use TTL=1, with option to configure. TTL=1 packets will never be forwarded.
 - Use TTL=255 and add the GTSM security feature.
The IETF DYMO draft specifies GTSM. DYMO uses RFC5444 message and packet
format, which is also used for OLSRv2 / NHDP.
Let's wait what the NHDP / OLSRv2 RFCs define, and follow that one.

Teco

Op 25 jan 2011, om 23:22 heeft Juliusz Chroboczek het volgende geschreven:

>>> TTL=1 should work on tunnels.
> 
>> only if the tunneled packets do not inherit ttl from their payload,..
> 
> FWIW, I use TTL=1 in Babel, and have received no complaints.  Of course,
> I've got way fewer users than you do.
> 
> --Juliusz





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