Here's something to chew on. As an end-node site who has recently become
triply-homed I've been wondering whether it would be useful if routers had
a way of making a route selection based on output queue levels.
Not. That will cause reordering of packets, and so trigger false
TCP retransmits.
Ie., let's say I have 2 paths to a destination of equal as-path distance
through neighbor A and neighbor B. Based on recent discussion it sounds
like IOS will send the packet to the neighbor with the lowest IP address.
Not. This is a default tie-breaking rule in cisco's BGP implementation,
and doesn't have anything to do with packet forwarding.
--vadim
>Here's something to chew on. As an end-node site who has recently become
>triply-homed I've been wondering whether it would be useful if routers had
>a way of making a route selection based on output queue levels.
Not. That will cause reordering of packets, and so trigger false
TCP retransmits.
It could be stream based (address and port), and use a LRU cache with a
planned capacity of 5 minutes, to decide on which interface to use. Sure,
it is more complicated, but anything you add increases complexity.
Has anybody collected stream duration data? What does the distribution
look like? 98% of streams last how long? (I bet less than 5 minutes)
I think something like this was brought up at the Ann Arbor NANOG.
Mike.
+------------------- H U R R I C A N E - E L E C T R I C -------------------+
What are you calling a 'stream' ? People are starting to collect flow
data in quite a few places with some interesting results.
-jh-