North American Network Operators Group

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Re: IP failover/migration question.

  • From: Edward B. DREGER
  • Date: Sun Jun 11 23:30:47 2006

RB> Date: Sun, 11 Jun 2006 17:02:14 -1000
RB> From: Randy Bush

RB> persistent tcp connections from clients would not fare well unless
RB> you actually did the hacks to migrate the sessions, i.e. tcp serial
RB> numbers and all the rest of the tcp state.  hard to do.

Actually, the TCP goo isn't too terribly difficult [when one has kernel
source].  What's tricky is (1) handling splits, and (2) ensuring that
the app is consistent and deterministic.

One transit provider handling multiple locations shouldn't present a
problem.  Of course many things that should be, aren't.

== below respsonses are general, not re Randy's post ==

Note also that redundancy/propagation is at odds with RTT latency.  The
proof of this is left as an exercise for the reader.

Finally, an internal network between locations is a good thing.  (Hint:
compare internal convergence times with global ones.)

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