Problem:
S,G entry has iif = oif in FHR is LHR case.
Setup:-
R11-----R2----R4
R11 :- FHR and LHR
R2 :- RP
R4 :- LHR
Issue :-
1) shut mapped interface in R11
2) wait for 5 min
3) do FRR restart
5) No shut of mapped interface
OIL is added for local interface also where OIL is same as IIF
and duplicate traffic observed on R4 receives in Ixia
RCA:
pim_ifchannel_local_membership_add adds inherited oif from starg when iif for
SG is unavailable.
When rpf for that SG resolves to this inherited oif from starg, iif is also in oif.
This results in dup traffic.
Fix:
If iif is not available, do not inherit from starg.
Signed-off-by: Mobashshera Rasool <mrasool@vmware.com>
__FILE__, __func__, child->sg_str,
ifp->name, up->sg_str);
+ if (!child->rpf.source_nexthop.interface) {
+ /* when iif unknown, do not inherit */
+ if (PIM_DEBUG_EVENTS)
+ zlog_debug(
+ "Skipped (S,G)=%s(%s) from %s: no iif",
+ child->sg_str, ifp->name,
+ up->sg_str);
+ continue;
+ }
+
ch = pim_ifchannel_find(ifp, &child->sg);
if (pim_upstream_evaluate_join_desired_interface(
child, ch, starch)) {