topic Thats right and i am using in Routing and SD-WAN

multicast WAN edge router sparse mode

farooq_0923@hotmail.com — Tue, 05 Mar 2019 10:44:46 GMT

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

Can you clarify what you mean

Jon Marshall — Fri, 13 Nov 2015 17:42:23 GMT

Can you clarify what you mean about the (<src IP>, G) entry ?

The src IP should be the sender which is presumably at the main site.

Also is the RP at the main site and is it actually the hub router ?

Jon

Hi Jon

farooq_0923@hotmail.com — Fri, 13 Nov 2015 17:48:13 GMT

Hi Jon

Thanks for reply, i issue ping to multicast address and source it from lan switch .

lan switch= ping 239.101.101.10 source 192.168.1.1

and then when i do show ip mroute on wan edge router for that site (LHR) i see one of the entry as being (192.168.1.1, 239.101.101.10) with LAN interface on router as being incoing interface and OIL is wan interface.

RP reside behind hub router in the core. Let me know if you need any other info, thanks alot.

regards

You will see that because the

Jon Marshall — Fri, 13 Nov 2015 17:54:48 GMT

You will see that because the switch is acting as the source for a multicast stream so your WAN router is recording it correctly.

If you are trying to troubleshoot receiving multicast at the remote site then the above is not a valid test and tells you nothing.

What is the muilticast group address you are trying to join at the remote site ?

What does the mroute table show for that group address ?

Jon

so if i were to ping

farooq_0923@hotmail.com — Fri, 13 Nov 2015 18:05:19 GMT

so if i were to ping multicast feed from lan with ip address of switch the edge router sees lan switch ip address as sender of feed...intresting :).... iam trying to joing 239.97.7.251....

But if that ping is not valid how else can i test whether branch is receiving feed or not ?

i suppose ping from RP or RP has always shortedt path tree from source anyway ?

morute does show (*,G) (*,239.97.7.251) entry but OIL interface is Null and after pinging i was expacting it to be lan interface...RP is listed and so is rpf and correct incoming interface (wan)...ta

You need to send an IGMP join

Jon Marshall — Fri, 13 Nov 2015 18:10:36 GMT

You need to send an IGMP join for that group so that your router knows it needs to request the stream from the RP.

What client are you using at the remote site ?

What is interesting is your router is showing a (*, G) entry which suggests something has at least requested the stream.

Can you post the out of the "sh ip mroute" for that group and also "sh ip pim rp" and "sh ip pim rp mapping".

Jon

we just used url that has

farooq_0923@hotmail.com — Fri, 13 Nov 2015 18:17:08 GMT

we just used url that has several embedded links for multicast feed....user paste url in browser and then expact the feed....through that browse igmp request is sent...can you simulate igmp join request and send it from lan switch instead PC browser?....the only time i see (*,G) is when i send ping from lan to multicast ip address...

show ip mroute shows quite a few entry (IP's,G) when i do show ip route on them IP's they all coming from branch LAN...

show ip pim rp and show ip pim rp mapping for the 239 feed are pointing to same RP which is behind the Hub in the CORE.

and flag of show ip mroute is set to "spt bit set" and doesnt change from it when i do repeated show ip mroute...ta

You can temporarily use your

Jon Marshall — Fri, 13 Nov 2015 18:22:12 GMT

You can temporarily use your router or switch if it is L3 to send an IGMP join request.

Don't know what you mean about the (<src IP>, G) entries all coming from the LAN ie. do you mean the incoming interface or OIL ?

I would have thought they should be coming from WAN.

Jon

all the swicthes are layer 3,

farooq_0923@hotmail.com — Fri, 13 Nov 2015 18:26:13 GMT

all the swicthes are layer 3, i would google to see how send igmp join message....

By (src ip , G ) i mean when i start pinging feed address from lan switch i see multiple entries like below

(192.168.1.1, 239.97.7.251)

incoming interface LAN interface

Outgoing interface WAn interface

(192.168.2.1, 239.97.7.251)

incoming interface LAN interface

Outgoing interface WAn interface

its not right behaviour and maybe due to the fact tha when i send ping from lan its sends it everyone locally ....Ta

Pinging does not send an IGMP

Jon Marshall — Fri, 13 Nov 2015 18:31:24 GMT

Pinging does not send an IGMP join, it generates it's own multicast stream.

You probably want to remove those entries from the mroute table.

Jon

I know pinging point just

farooq_0923@hotmail.com — Fri, 13 Nov 2015 18:31:25 GMT

I know pinging point just learnt from urself :)....i would simulate igmp join from switch and see what results i get ....checking now 🙂 thanks alot for your help...

Sorry, should have realised I

Jon Marshall — Fri, 13 Nov 2015 18:45:56 GMT

Sorry, I should have realised I had already explained that 🙂

See what an IGMP join does and come back if it still isn't working.

Jon

Hi Jon

farooq_0923@hotmail.com — Fri, 13 Nov 2015 19:09:28 GMT

Hi Jon

Sure, i would check and let yourself...thanks alot for your help 🙂

HI ...Just checked feed and

farooq_0923@hotmail.com — Fri, 13 Nov 2015 23:42:49 GMT

HI ...Just checked feed and only one is accessible....for other two the (*,g) entries are correct...s,g are correct as well...on LHR both OIL and IFF interface are correct ...flag for sg is T but no feed or url...and after few minutes s,g changes the correct OIL to NULL...

So for a multicast stream

Jon Marshall — Fri, 13 Nov 2015 23:51:30 GMT

So for a multicast stream that doesn't work even though you see the correct entries in the mroute table you are not seeing any traffic on the client ?

Is that correct ?

Is this with a client sending an IGMP join or you doing it on the L3 switch ?

Might need some outputs but can you answer the above first.

Jon

Thats right and i am using

farooq_0923@hotmail.com — Sat, 14 Nov 2015 00:18:38 GMT

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

IGMP timeouts may be an issue

Jon Marshall — Sat, 14 Nov 2015 00:42:29 GMT

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

thanks for clarification ..

farooq_0923@hotmail.com — Sat, 14 Nov 2015 00:42:30 GMT

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....

FHR show ip mroute values are

farooq_0923@hotmail.com — Sat, 14 Nov 2015 00:46:17 GMT

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)....

Okay that suggests PIM

Jon Marshall — Sat, 14 Nov 2015 00:46:42 GMT

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