RE: IPv4 Multicast

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1

Make sure you have
"ip multicast-routing"
on both routers.

On the router interfaces, make sure you have
"ip pim sparse-mode"

On both routers, make sure you have the same rp address assigned and that you can ping this ip address from both routers. (I prefer to make it a loopback interface)
"ip pim rp-address w.x.y.z"

Also, make sure that routing is setup on your routers so that your receiver can ping your sender.

On your routers you should be able to see the source unicast address and multicast address by typing "show ip mroute"
you should see something like this:
(*, 239.192.3.47), 7w0d/00:02:59, RP 10.31.0.1, flags: S
   Incoming interface: Null, RPF nbr 0.0.0.0
   Outgoing interface list:
     Port-channel15, Forward/Sparse, 7w0d/00:02:59, H

(10.5.9.51, 239.192.3.47), 4w5d/00:03:27, flags: TA
   Incoming interface: Port-channel15, RPF nbr 10.7.193.138
   Outgoing interface list:
     Port-channel17, Forward/Sparse, 4w5d/00:02:49, H

On your switches, with igmp snooping enabled, you should be able to type:
"show ip igmp snooping group" and see something like
Vlan Group Type Version Port List

2

verify packets actually land on the receiver (tcpdump, etc) interface. verify that your host has a route for 224/4 pointing out the interface you hope joins are leaving from. ensure iptables isn't blocking either the outgoing igmp join, and make sure that it's permitting the incoming mcast-dest packets.

if any of these are wrong/failing, then mcast won't work.

-Tk

3

I also add on the 'override' term at the end, because any auto-rp messages will be preferred over the static config unless you set override.

- Jared

4

I have all those things you mentioned below.
The VLC server (10.0.1.2) sends out 2 streams on 239.255.0.1 & 239.255.0.2
I see both in SAP, when I try to join 239.255.0.2, nothing happens in VLC
and below you have the output of my routers & switches at that time:

On my RP router I see for show ip mroute:

(*, 239.255.255.255), 5d04h/00:03:26, RP 172.16.0.2, flags: SJCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    FastEthernet0/1, Forward/Sparse, 1d06h/00:03:26
    FastEthernet0/0.200, Forward/Sparse, 5d04h/00:02:41

(10.0.1.2, 239.255.255.255), 1d06h/00:03:28, flags: LT
  Incoming interface: FastEthernet0/0.200, RPF nbr 0.0.0.0
  Outgoing interface list:
    FastEthernet0/1, Forward/Sparse, 1d06h/00:03:26

(*, 239.255.0.2), 00:01:10/00:03:19, RP 172.16.0.2, flags: S
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    FastEthernet0/1, Forward/Sparse, 00:01:10/00:03:19

(*, 239.255.255.250), 00:07:19/00:03:07, RP 172.16.0.2, flags: S
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    FastEthernet0/1, Forward/Sparse, 00:07:22/00:03:03

(*, 239.195.255.255), 1d06h/00:02:39, RP 172.16.0.2, flags: S
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    FastEthernet0/1, Forward/Sparse, 00:01:24/00:02:39

(*, 224.2.127.254), 5d04h/00:03:10, RP 172.16.0.2, flags: SJCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    FastEthernet0/1, Forward/Sparse, 1d06h/00:03:10
    FastEthernet0/0.200, Forward/Sparse, 5d04h/00:02:38

(*, 224.0.1.40), 5d04h/00:02:40, RP 172.16.0.2, flags: SJCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    FastEthernet0/1, Forward/Sparse, 1d06h/00:02:59
    FastEthernet0/0.200, Forward/Sparse, 5d04h/00:02:40

On my other router I have:

(*, 239.255.255.255), 5d04h/stopped, RP 172.16.0.2, flags: SJCL
  Incoming interface: FastEthernet0/1, RPF nbr 192.168.0.2
  Outgoing interface list:
    FastEthernet0/0.200, Forward/Sparse, 5d04h/00:02:54

(10.0.1.2, 239.255.255.255), 1d06h/00:02:58, flags: LJT
  Incoming interface: FastEthernet0/1, RPF nbr 192.168.0.2
  Outgoing interface list:
    FastEthernet0/0.200, Forward/Sparse, 1d06h/00:02:54

(*, 239.255.0.2), 00:01:55/00:02:56, RP 172.16.0.2, flags: SJC
  Incoming interface: FastEthernet0/1, RPF nbr 192.168.0.2
  Outgoing interface list:
    FastEthernet0/0.200, Forward/Sparse, 00:01:55/00:02:56

(*, 239.255.255.250), 00:08:04/00:02:53, RP 172.16.0.2, flags: SJC
  Incoming interface: FastEthernet0/1, RPF nbr 192.168.0.2
  Outgoing interface list:
    FastEthernet0/0.200, Forward/Sparse, 00:08:04/00:02:53

(*, 239.195.255.255), 5d04h/00:02:50, RP 172.16.0.2, flags: SJC
  Incoming interface: FastEthernet0/1, RPF nbr 192.168.0.2
  Outgoing interface list:
    FastEthernet0/0.200, Forward/Sparse, 00:02:08/00:02:50

(*, 224.2.127.254), 5d04h/00:02:48, RP 172.16.0.2, flags: SJCL
  Incoming interface: FastEthernet0/1, RPF nbr 192.168.0.2
  Outgoing interface list:
    FastEthernet0/0.200, Forward/Sparse, 5d04h/00:02:48

(*, 224.0.1.40), 5d04h/00:02:52, RP 172.16.0.2, flags: SJCL
  Incoming interface: FastEthernet0/1, RPF nbr 192.168.0.2
  Outgoing interface list:
    FastEthernet0/0.200, Forward/Sparse, 5d04h/00:02:52

On the switch where the RP is connected:

Vlan Group Version Port List

5

Does "show ip mroute count" on the 1841 (RP) display activity on traffic
counters?

Is the VLC sender directing multicast to the 1841 (RP) thru a default route?

Is the VLC sender issuing multicast packets with a high-enough multicast TTL
?

Everton

6

Woot! It was the TTL on the VLC sender that was on default, changed it to 10
and now and I have my video.

Thanks for your help.

7

One more question:

If I would now connect another switch (WS-C3524-XL) between the VLC receiver
and the 3560G like this:

VLC receiver - 3524XL - 3560G - 1841 - 1841 - 4503 - VLC sender

That 3524XL only supports CGMP, what do I need to change on the config to
not broadcast this multicast traffic?

Do I need to configure the ip cgmp router-only on the 1841 at Receiver?

8

We have been struggling to locate someone at AT&T that handles the
txt.att.net servers. We have clients in our data center that can no
longer send emails to mobile phones via 10digit@txt.att.net. We have
contacted AT&T and they say there is no problem on their end. We can
ping the server, but simply cannot connect to port 25. We have checked
all firewalls of each client. Some ranges of IPs work and others don't.
Looking for someone with a clue who can assist.

Mike Walter

9

this is not a guaranteed service, nor does it have an official SLA,
and inbound mail/connections from louder speakers are often just
dropped, either at the TCP layer, or at the application layer (even
after what seems like a completed SMTP conversation.)

If you depend upon SMS for things, smtp -> sms gateways at the
provider aren't reliable enough.

10

Something weird today when I did some more tests today...

When I configured a subinterface with the: ip pim sparse-mode

(config)#int GigabitEthernet 3/0.310
(config-subif)#ip pim sparse-mode
May 31 15:48:40.218 CET: %PIM-5-DRCHG: DR change from neighbor 0.0.0.0 to
10.11.130.1 on interface GigabitEthernet3/0.310

At that point all my L2TPv3 tunnels on the other subinterfaces on Gi3
stopped working.
When I removed the command, everything came back up again.

Is this a bug or am I missing something?

Regards,

Rens