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Re: ipsec error protocol

Also, this is only an issue for non-TCP protocols.  TCP will notice
the lack of acknowledgement and backoff packet transmission.  It will
not constantly send packets for the full duration of the outage.

-derek

"Joseph D. Harwood" <jharwood@vesta-corp.com> writes:

> >
> > You raise an interesting issue. The second example I think is not
> > credible, i.e., an SA lifetime of a year. But, in the context of a
> > unidirectional traffic flow, a serious outage might be long enough at
> > very high speeds to cause the counter to wrap more than once,
> > creating ambiguity at the receiver and a loss of synch.  If we adopt
> > any of the keep alive (or is that make dead?) proposals, we have a
> > chance to detect and address this problem, but we do need to think
> > about this and have a good answer.
> >
> > Steve
> >
> 
> I had also wondered about the situation where an outage occurs that lasts
> long enough for the Sequence Number to wrap a few times.  Perhaps a
> unidirectional message between IKE peers (sender -> receiver) every time the
> sending Sequence Number wraps at bit 31?  This mechanism would be redundant
> when there are no link problems, but would enable resynchronization when the
> link went down for a while.  Even if some of these messages get dropped
> after the link comes back up, eventually one of the messages would get
> through and synchronization would be restored (i.e., don't have to have
> ack's or reliable transport for this notification message).
> 
> 
> Best Regards,
> Joseph D. Harwood
> jharwood@vesta-corp.com
> www.vesta-corp.com
> 
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-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
       warlord@MIT.EDU                        PGP key available
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