[Xorp-users] Xorp delayed actions

[Atanu Ghosh]

Hi,

As a general principle in our routing protocol implementations we have
tried to react immediately to a protocol packet (or other event)
signalling a topology change. The one exception at the moment is OSPF,
which, when it notices a topology change schedules a full routing
computation to take place in 5 seconds (perhaps 1 second would be
better choice).

The optimal way of dealing with a routing change is to only recompute
the affected part of the topology. The OSPF code was designed to perform
incremental spf computation. Unfortunately some of the dependency
tracking turned out to be very complicated and posed the danger of
taking more time to compute than running the full computation. We made
the pragmatic decision to complete the OSPF implementation and go back
to the incremental computation at a later date when we had gained more
experience with all the issues.

   Atanu.

>>>>> "riccardo" == riccardo  <riccardo.sciaccaluga@tin.it> writes:

    riccardo> Hi i made up some switching time test with xorp as
    riccardo> follows: 1)I set up a network with two possible path to
    riccardo> the same destination but with different metric 2)I start
    riccardo> sending ip packets over this network towards the
    riccardo> destination node 3)I turned up the metric of the old low
    riccardo> cost path to make it the the new higher cost one.  4)I
    riccardo> sniffed the ip traffic over these links and i make this
    riccardo> experiment lot of times The thing i noticed is that xorp
    riccardo> needs 5 to 6 seconds to switch the traffic to the new low
    riccardo> cost path.  I thing that this time is too long but i also
    riccardo> thing that it could be because of some delayed action(like
    riccardo> delayed spf scheduling or delayed access to te routing
    riccardo> table or whatever).  My questions are: what are the
    riccardo> default delayed action that xorp does and their delay
    riccardo> value?  Where can i find this information inside xorp
    riccardo> code?  Thanks in advance for your help.
    riccardo> _______________________________________________ Xorp-users
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