Mike and I did some work on this this afternoon
We propose the following algorithm for calculating
extend P space with avoids stub node problem
and also addresses a problem in the pseudocode
that excluded the use of a parallel link.
/////////////////////////////////////////////////////////////////
//
// Calculate extended P-space
//
// Note the strictly less than operator is needed to
// avoid ECMP issues.
Compute_Extended_P_Space(fail_intf)
foreach node y in network
y.in_extended_P_space = false
// Extend P-space to the P-spaces of all reachable
// neighbours
foreach interface intf in self
// Exclude failed interface, noting that
// the node reachable via that interface may be
// reachable via another interface (parallel path)
if (intf != fail_intf)
foreach neighbor n in intf.remote_node
// Apply RFC5286 Inequality 1
if ( D_opt(n, y) <
D_opt(n,self) + D_opt)(self, y)
y.in_extended_P_space = true
It might seem strange to run rlfa to a node via a parallel
link, but it would work and it seems strange to exclude it,
particularly as some would like to use only rlfa.
I have also extended the code to exclude the accidental
selection of a pseudonode as PQ and the use of a repair
first hop that is reachable through a pseudonode.
Note that RFC5286 does not seem to explicitly call
out the case where the first hop is a pseudonode.
Stewart
_______________________________________________
rtgwg mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/rtgwg
