multicast WAN edge router sparse mode

[farooq_0923@hotmail.com]

Hi All

Hope you well. I have a multicast issue and was wondering if someone can help. We have multiple remote sites connected to hub end router and some sites cant receive multicast feed. we are using pim sparse mode with static RP. every time i try to ping multicast feed from lan switch i do get 

(*,G) entry with correct RP, RPF nbr and incoming interface on LHR but for OIL interface iam getting none. on Last hop router (LHR) i should see OIL interface as pointing to lan since igmp join request is coming from LAN.

Also i do see (lan src ip , G) entry in mrouting table but again incoming interface is pointing to lan, no rp details and outgoing interface is WAN.

can someone advise or point iin right direction. thanks

regards

M

[farooq_0923@hotmail.com]

Thats right and i am using URL from branch machine ...so i do see correct (*,g) and (S,g) entry but feed iam only getting for one stream...so LHR everything seems ok but after few minutes no feed for other two streams and i do get null for OIL thats probably due to IGMP time out...i have traced alll the three feeds to FHR(firt hop router) ...

now for feed that is working on its FHR i  see (*,G) and (s,G) but incoming interfaces are diff both tree's, one is layer 3 port channel and one is svi completely different subnet...so (s,g) has correct incoming interface and correct OIL (portchannel 21) for (*,G) incoming is (portchannel21 same) and OIL is null....but feed is working so nothing to worry about same RP as branch....RP is BTW anycast so assigned to multiple ip interfaces in network....

Feed that is not working on its FHR is see (*,G) and (s,G)...RP is correct incoming interface for (*,G) is incorrect as that interface is used to reach RP..and OIL is NULL...(S,G) IFF is correct RPf is 0.0.0.0 and OIL is NULL...when i check show ip pim rpf RP add it has the route to get to RP and plus when i do show ip mroute count i  can see forward and received packets.. iam using two ddiff laptop trying to figure out how can i send you output ....ta

[Jon Marshall]

IGMP timeouts may be an issue if the clients don't respond to IGMP queries from the router so that is one thing to think about.

For the feed that is working you only need to worry about the (<src IP>, G) entry and that should be accurate.

Don't worry about the other entry for the same group because between the RP and the source the IIF and OIL can be a bit confusing sometimes.

For the feed that is not working can you answer -

1) is the router connected to the source  of the non working feed a different router than for a working feed ?

If it is different then -  

2) what does a "sh ip pim neighbor" show on that router ?

3) if there are other routers between the source router and the RP what does "sh ip pim neighbor" show on those as well.

Jon

[farooq_0923@hotmail.com]

thanks for clarification ...all three FHR are different routers and i just checkd from another branch all three feeds are working even the non working feed FHR OIL and IFF are correct now .....i am checking everything yourself aasked now....

[farooq_0923@hotmail.com]

FHR show ip mroute values are correct for S,G but LHR iam only seeing (s,G) all the feeds are working and no (s,G) entries only (*,G)....

[Jon Marshall]

Just to clarify.

Are you saying the LHR only sees (*, G) entries ?

Jon

[farooq_0923@hotmail.com]

yes thats right...LHR only sees (*,G) and all feed from that branch working ....

[Jon Marshall]

Sorry I am getting really confused now between branches, RPs what works and what doesn't.

If the feeds are working then you would expect to see (<src IP>, G) entries unless you have disabled the SPT switchover ?

Can we step back and work through this logically.

So b1 is a branch where all feeds work properly and b2 is where some feeds work but there is at least one that doesn't.

The non working feed is m1.

So is the path to the RP for b1 and b2 the same ?

Is the path to the FHR for m1 the same for both b1 and b2 ?

I am assuming so because presumably all branches go via the hub and the RP and FHR are at the hub site ?

Jon

[farooq_0923@hotmail.com]

sorry for confusion ....let me explian, to get to RP from b1 and b2 path is not same as they are going via different hops....b1 is not showing (s,G ) so assuming its feed is from same source as b2 which does show (s,g) but no feed...did a trace based on that assumption and few hops were same and rest different even the last destination box was different :):)...i think we onto something

[Jon Marshall]

So at b1 all feeds are working but there are no (<src IP>, G) entries.

Is that correct ?

If so can you check b1 router and see if you see this command in the configuration -

"ip pim spt-threshold infinity"

because if that is not there you should be seeing host specific group entries.

I am just trying to work out what is meant to happen.

I suspect it is to do with the topology and a missing PIM neighbor or an RPF failure but first I want to work out why b1 is only using (*, G) entries and if that is meant to be used at every branch.

Do you know ?

Jon

[farooq_0923@hotmail.com]

yes thats right B1 all feeds working but no (s,G) only (*,G)...did show run | sec bidir and infinity and various variation but dont think its bidirectional or spt inifinty configured...:(

[Jon Marshall]

As far as I know unless you configure the spt infinity (or a threshold) or you are using Bidir-PIM there will always be (<src IP>, G) entries because the default behaviour is to switch over to the SPT for any stream.

So I don't understand how they are working.

Are you absolutely sure ie. did you just do a "sh run" and checked the configuration ?

Anyway I still suspect it could be the issue with a different path so you need to go hop by hop from the branch router all the way to the source.

On each router -

1) check the IP routing table for the route to the source IP of the stream ie.what is the next hop router.

2) check with "sh ip pim neigbor" that the next hop router used to get to the source is  a PIM neigbor

3) check the mroute table.

I would say you should be looking for a (<src IP>, G) entry but the entries you are seeing at b1 which works don't have those so you will just have to see what they show.

Like i say though if you are not seeing Bidir or any spt threshold being set then I don't fully understand what is happening.

Would need you to start posting outputs.

I have to log off now but the above should keep you busy for a while :-)

I'll check in with this thread tomorrow.

Jon

[farooq_0923@hotmail.com]

no probs at all ....thanks aloot for all the help support and guidance and iam on it ...have a great weekend...tc

[Jon Marshall]

Just to check.

You are not running Bidirectional PIM are you ?

Jon

[Jon Marshall]

Is each branch using a different RP then ?

So for a branch that works for a feed that doesn't work in your problem branch is the RP the same or a different one ?

Jon

[farooq_0923@hotmail.com]

FHR show ip mroute values are correct for S,G (non working feed but working for another branc h now) but LHR iam only seeing (s,G) all the feeds are working and no (s,G) entries only (*,G)....they all using same RP but RP is anycast and from same region...