[c-nsp] Enabling multicast routing on 3750G platform

Matthew Huff mhuff at ox.com
Fri Jan 30 09:19:28 EST 2015 

Use igmp-join if you want the router itself to be a member of the multicast group. You don't need it if you are routing multicast through the router. It's rarely used and only for very specific circumstances, for example if a servers fails if there isn't at least one client joining, etc...

 

----
Matthew Huff             | 1 Manhattanville Rd
Director of Operations   | Purchase, NY 10577
OTA Management LLC       | Phone: 914-460-4039
aim: matthewbhuff        | Fax:   914-694-5669

-----Original Message-----
From: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Lobo
Sent: Thursday, January 29, 2015 9:00 PM
To: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Enabling multicast routing on 3750G platform

Problem solved!

You guys were right about VLC and its TTL.  Turns out there's a bug in the
program where changing the TTL in the GUI doesn't affect streaming for some
reason.  I added a ttl=30 to the string and the stream started flowing to
the secondary port.  I even changed things back to vlans and it routed
perfectly fine.

I have a question about one comment that was made regarding the igmp-join
command.  In all the documentation I've read, it says to put that command
on the interfaces that plan on receiving the stream(s).  Some comments
suggested removing it or not needing it and with my own testing it clearly
works fine even without this command.  Why is that?

This is the final show ip mroute:

Switch#sh ip mroute
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
       L - Local, P - Pruned, R - RP-bit set, F - Register flag,
       T - SPT-bit set, J - Join SPT, M - MSDP created entry,
       X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
       U - URD, I - Received Source Specific Host Report,
       Z - Multicast Tunnel, z - MDT-data group sender,
       Y - Joined MDT-data group, y - Sending to MDT-data group
       V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 239.255.255.250), 02:45:34/00:02:34, RP 3.3.3.3, flags: SJC
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Vlan100, Forward/Sparse, 00:00:38/00:02:34
    Vlan200, Forward/Sparse, 02:42:59/00:02:32

(*, 239.0.0.1), 02:45:35/stopped, RP 3.3.3.3, flags: SJC
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Vlan200, Forward/Sparse, 02:42:15/00:02:33

(1.1.1.1, 239.0.0.1), 00:00:40/00:02:58, flags: JT
  Incoming interface: Vlan100, RPF nbr 0.0.0.0
  Outgoing interface list:
    Vlan200, Forward/Sparse, 00:00:40/00:02:33

(*, 224.0.1.40), 02:45:35/00:02:28, RP 3.3.3.3, flags: SJCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Loopback0, Forward/Sparse, 02:45:36/00:02:27

Switch#


Thanks again for the tips everyone!

Jose

On Thu, Jan 29, 2015 at 7:23 AM, Adam Vitkovsky <avitkovsky at gammatelecom.com
> wrote:

> Hi Lobo,
>
> Ok so the SW is indeed a DR on port GigabitEthernet1/0/1 and it's
> obviously receiving some stream in which case it should create an (s,g)
> state and send a register msg to the RP and RP should update its group
> cache (all should be done internally since the DR=RP).
> However none of this is happening most likely because the switch doesn't
> like something about the stream (destination mac address, ttl, som security
> feature,..).
> Can you do: debug ip pim
> -to see if it shows why the switch ignores the incoming stream.
> -or some other techniques to see why the incoming multicast frames are
> being dropped silently.
>
>
> adam
> > -----Original Message-----
> > From: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of
> > Lobo
> > Sent: 29 January 2015 00:57
> > To: cisco-nsp at puck.nether.net
> > Subject: Re: [c-nsp] Enabling multicast routing on 3750G platform
> >
> > I've moved the configuration on the switch so that the ports are routed
> now
> > instead of using vlans but still no go.
> >
> > Here is the output from a show ip mroute:
> >
> > Switch#sh ip mroute
> > IP Multicast Routing Table
> > Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C -
> Connected,
> > L - Local, P - Pruned, R - RP-bit set, F - Register flag,
> > T - SPT-bit set, J - Join SPT, M - MSDP created entry,
> > X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
> > U - URD, I - Received Source Specific Host Report,
> > Z - Multicast Tunnel, z - MDT-data group sender,
> > Y - Joined MDT-data group, y - Sending to MDT-data group
> > V - RD & Vector, v - Vector
> > Outgoing interface flags: H - Hardware switched, A - Assert winner
> > Timers: Uptime/Expires
> > Interface state: Interface, Next-Hop or VCD, State/Mode
> >
> > (*, 239.255.255.250), 00:01:03/00:02:56, RP 3.3.3.3, flags: SJC
> > Incoming interface: Null, RPF nbr 0.0.0.0
> > Outgoing interface list:
> > GigabitEthernet1/0/2, Forward/Sparse, 00:01:03/00:02:06
> > GigabitEthernet1/0/1, Forward/Sparse, 00:01:03/00:02:56
> >
> > (*, 239.0.0.1), 00:01:22/00:02:56, RP 3.3.3.3, flags: SJCL
> > Incoming interface: Null, RPF nbr 0.0.0.0
> > Outgoing interface list:
> > GigabitEthernet1/0/2, Forward/Sparse, 00:01:23/00:02:56
> >
> > (*, 224.0.1.40), 00:01:23/00:02:08, RP 3.3.3.3, flags: SJCL
> > Incoming interface: Null, RPF nbr 0.0.0.0
> > Outgoing interface list:
> > Loopback0, Forward/Sparse, 00:01:23/00:02:08
> >
> > Switch#
> >
> > Switch#sh ip pim interface
> >
> > Address Interface Ver/ Nbr Query DR DR
> > Mode Count Intvl Prior
> > 3.3.3.3 Loopback0 v2/S 0 30 1
> > 3.3.3.3
> > 1.1.1.2 GigabitEthernet1/0/1 v2/S 0 30 1
> > 1.1.1.2
> > 2.2.2.2 GigabitEthernet1/0/2 v2/S 0 30 1
> > 2.2.2.2
> > Switch#
> >
> > The traffic is still coming in on port 1:
> >
> > Switch#sh int g1/0/1
> > GigabitEthernet1/0/1 is up, line protocol is up (connected)
> > Hardware is Gigabit Ethernet, address is 0018.73bf.12c1 (bia
> > 0018.73bf.12c1)
> > Internet address is 1.1.1.2/24
> > MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
> > reliability 255/255, txload 1/255, rxload 12/255
> > Encapsulation ARPA, loopback not set
> > Keepalive set (10 sec)
> > Full-duplex, 100Mb/s, media type is 10/100/1000BaseTX
> > <snip>
> > 30 second input rate 4822000 bits/sec, 444 packets/sec
> > 30 second output rate 0 bits/sec, 0 packets/sec
> >
> > but not exiting on port 2
> >
> > Switch#sh int g1/0/2
> > GigabitEthernet1/0/2 is up, line protocol is up (connected)
> > Hardware is Gigabit Ethernet, address is 0018.73bf.12c2 (bia
> > 0018.73bf.12c2)
> > Internet address is 2.2.2.2/24
> > MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
> > reliability 255/255, txload 1/255, rxload 1/255
> > Encapsulation ARPA, loopback not set
> > Keepalive set (10 sec)
> > Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
> > <snip>
> > 30 second input rate 4000 bits/sec, 6 packets/sec
> > 30 second output rate 1000 bits/sec, 1 packets/sec
> >
> > I've changed the TTL on VLC to 10 and I've also changed things to
> > sparse-mode and put it on the loopback as well.
> >
> > Any other suggestions?
> >
> > !
> > interface Loopback0
> > ip address 3.3.3.3 255.255.255.255
> > ip pim sparse-mode
> > !
> > interface GigabitEthernet1/0/1
> > no switchport
> > ip address 1.1.1.2 255.255.255.0
> > ip pim sparse-mode
> > load-interval 30
> > spanning-tree portfast
> > !
> > interface GigabitEthernet1/0/2
> > no switchport
> > ip address 2.2.2.2 255.255.255.0
> > ip pim sparse-mode
> > ip igmp join-group 239.0.0.1
> > load-interval 30
> > spanning-tree portfast
> > !
> > ip routing
> > no ip domain-lookup
> > !
> > !
> > ip multicast-routing distributed
> > !
> > !
> > ip pim rp-address 3.3.3.3
> > !
> >
> > Jose
> >
> > On Wed, Jan 28, 2015 at 4:43 PM, Lobo <lobotiger at gmail.com> wrote:
> >
> > > Thanks for the replies. I'll post a show mroute and tweak the VLC
> > > parameters once I get access to the device tonight. BTW, all of this
> > > testing is just on a single switch so no other topology exists.
> > >
> > > Jose
> > >
> > > On Wed, Jan 28, 2015 at 12:55 PM, Adrian Minta
> > <adrian.minta at gmail.com>
> > > wrote:
> > >
> > >> Hi,
> > >> look for the stream TTL.
> > >>
> > >> On 28.01.2015 19:37, Lobo wrote:
> > >>
> > >>> Hi everyone. I've been trying to get multicast routing to work on a
> > >>> single
> > >>> 3750G switch between two vlans but for the life of me it just doesn't
> > >>> work. When the host and receiver are on a single vlan the streaming
> > >>> works
> > >>> ....
> > >>> The server streaming via VLC is 1.1.1.1 and is using 239.0.0.1 for
> the
> > >>> multicast address. The receiver is 2.2.2.1 and using VLC to stream. I
> > >>> can
> > >>> see the traffic coming in on port 1 but no traffic leaving the
> switch's
> > >>> other port.
> > >>>
> > >>> BTW, I tried dense-mode and sparse-mode as well with similar results.
> > >>>
> > >>> Any thoughts?
> > >>>
> > >>> Jose
> > >>>
> > >>>
> > >> --
> > >> Best regards,
> > >> Adrian Minta
> > >>
> > >>
> > >>
> > >> _______________________________________________
> > >> cisco-nsp mailing list cisco-nsp at puck.nether.net
> > >> https://puck.nether.net/mailman/listinfo/cisco-nsp
> > >> archive at http://puck.nether.net/pipermail/cisco-nsp/
> > >>
> > >
> > >
> > _______________________________________________
> > cisco-nsp mailing list cisco-nsp at puck.nether.net
> > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > archive at http://puck.nether.net/pipermail/cisco-nsp/
>
>
> ------------------------------
> This email has been scanned for email related threats and delivered safely
> by Mimecast.
> For more information please visit http://www.mimecast.com
> ------------------------------
>
_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

More information about the cisco-nsp mailing list