cvs commit: src/sys/netinet ip_id.c

Mike Silbersack silby at
Wed Feb 6 18:49:38 PST 2008

On Thu, 7 Feb 2008, Bruce M. Simpson wrote:

> Mike Silbersack wrote:
>>    Note that this commit does not yet enable random IP ID
>>   generation by default.  There are still some concerns
>>   that doing so will adversely affect performance.
> Random ip_id generation also breaks MANET multicast as it's currently 
> specified -- the ip_id field gets used for histogram based duplicate packet 
> detection. However, after my inveigling, Fred Templin at Boeing brought 
> encapsulation back into the proposal on the table.
> So some way to turn this stuff off on a per-interface basis is probably going 
> to be needed later on for mobile stuff...
> later

Does MANET multicast require:

1) Sequentiality.
2) No repetition of an ID within a certain timeframe.

The distinction is quite important!

Mike "Silby" Silbersack

More information about the cvs-src mailing list