IGMP L2 to L3? 3

[dvtestguy]

I have a L2 IGMP environemnt that I need to change to L3 (unless my understanding is off?). I've configured the Source traffic (sending 100 Video streams starting Src 25.0.0.1 Dest 237.5.0.2) connected directly into the Querying switch (6506) in VLAN 193 (access mode).

interface G3/7
description Traffic Source
switchport
switchport access vlan 193
switchport trunk encapsulation dot1q
switchport trunk allowed vlan none
switchport mode access
switchport nonegotiate
spanning-tree portfast trunk
-----
interface G3/8
description receiving device
switchport
switchport access vlan 193
switchport trunk encapsulation dot1q
switchport trunk allowed vlan none
switchport mode access
switchport nonegotiate
spanning-tree portfast trunk

Cisco6500IOS#sh ip igmp sn mr
vlan ports
-----+-----------------------
193 Router

Cisco6500IOS#sh run int vlan 193
interface Vlan193
ip address 10.115.193.5 255.255.255.0
ip pim sparse-dense-mode

Cisco6500IOS#sh ip igmp group
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter
224.0.1.40 Vlan620 8w6d 00:02:23 10.115.62.5

My questions/Problems are; if I have a device that needs to send a Join and request 5-of-100 streams, then that device should only see 5-streams, right? However, since i'm running the port in access mode vlan 193 in L2, I see all 100, not just the 5 that I'm requesting.

Any ideas how to get to a true L3 environment?

 

[brianinms]

If you are running Multicast in sparse mode you have to have an RP.

http://www.cisco.com/en/US/products..._guide_chapter09186a00805a39cc.html#wp1128153

 

[dvtestguy]

No RP configured anywhere? Would that be the reason why I'm seeing ALL video traffic on the access vlan 193 ports?

Where would the RP be configured? In the Router or switch?

Thnaks...

 

[brianinms]

You would configure the RP on your 6506.

 

[ADB100]

IGMP is independant of Multicast routing, so I think you need to read and understand what IGMP is used for and also what options you have for routing multicast traffic between IP networks. Have a read here for a reasonable start:

http://www.cisco.com/en/US/tech/tk828/technologies_tech_note09186a0080094821.shtml

PIM Sparse-Mode seems to be the preferred solution as it ensures Multicast is only delivered to the specific hosts that request it. With Sparse-Mode you need to inform each of your routers where the RP is (or RP's are if you want to spread the load for different groups over different routers). You can either statically configure the RP addresses on each of your routers or use either Auto-RP or BSR. There are pro's and con's of either. This link should explain it for you:

http://www.cisco.com/en/US/tech/tk828/technologies_white_paper09186a00800d6b63.shtml

HTH

Andy

 

[dvtestguy]

Thanks guys!!!

The only qustion I have left...From my original post..."if I have devices that need to send a Join and request for 5-of-100 streams, then that device should only see 5-streams, right? However, since i'm running the port in access mode vlan 193 in L2, I see all 100, not just the 5 that I'm requesting."

Why am I still seeing ALL IGMP traffic on ALL ports, when neither of my devices have asked for a Join?

 

[ADB100]

Without an RP the groups will operate in Dense mode and this works in a flood & prune fashion. Every three minutes all your multicast will be flooded to your entire multicast domain, it should then be pruned back by the routers who have no active IGMP listeners for the groups.
In your network the source and receiver are on the same L2 network so I am not sure what the behaviour is here. Try the command:

show ip igmp snooping groups

and post the output.

Andy

 

[dvtestguy]

My setup is...

Traffic source (M-Cast traffic) --> 6506 (Server switch) <---> 4948 (Client switch) --> DUT for Join/Leave (or either connected to the 6506 as well on G3/8 on vlan 193)

Cisco6500IOS#show ip igmp snooping mr
vlan ports
-----+----------------------------------------
193 Router

Cisco4948#show ip igmp snooping groups
Vlan Group Version Port List
---------------------------------------------------------

What IP should the RP be? Should it be in the same subnet 10.115.193.x from my config above?

Thanks

 

[ADB100]

The RP is just a multicast router in your network, it could be any one however it is usually a good idea to keep it relatively close to the sources. I would normally use a loopback interface. You then need to tell your other multicast routers where it is - either statically or use Auto-RP or BSR (see the links I posted).

If the command 'show ip igmp snooping groups' is done on the switch where the receiver is you should see entries for each group a client has joined:

cat-3550#sho ip igmp snooping groups
Vlan      Group             Version     Port List
------------------------------------------------------------
10        239.255.255.254   v2          Fa0/1

HTH

Andy

 

[Minue]

Hello
Don't know if you have resolve the problem.In any case check to see that at layer 2 the access swithes are doing ip snooping.
Regards

 

[dvtestguy]

Minue,

The access switches (4948/4503 VTP Clients) are seeing the snooping, but the 6506 (which is the VTP server) are still sending all sourced M-Cast traffic, regarless of Join requests.

Cisco4948#sh ip igmp sn q
Vlan IP Address IGMP Version Port
----------------------------------------------
193 10.115.193.5 v2 Gi1/45

Cisco4948#sh ip igmp sn mr
Vlan ports
---- -----
193 Gi1/45(dynamic)

-----------------------------------------------

Cisco6500IOS#sh run int vlan 193
interface Vlan193
ip address 10.115.193.5 255.255.255.0
ip pim sparse-dense-mode
end

Cisco6500IOS#sh ip pim rp
Group: 239.255.33.1, RP: 10.115.75.13, uptime 04:52:34, expires never
Group: 224.0.1.40, RP: 10.115.75.13, uptime 1d07h, expires never

 

[Minue]

Hello
Your set up is quick simple,it should work.Something isn't clear to me.When you say "that device should only see 5-streams,However, since i'm running the port in access mode vlan 193 in L2, I see all 100"
What's the device?A workstation or the L2 switch?Also you should move to full "ip pim sparse-mode"
Regards

 

[dvtestguy]

Minue,

If I have a DUT connected to the 4948 (snooping switch) requesting an IGMP Join for 5 groups (out of 100 streams), then I should only see the requested 5, not all 100.

The device is a network analyzer/probe connected to the 4948 in access mode (for vlan 193)

 

[Minue]

The network analyzer could be doing tricky things.Are you seeing all 100 groups in the network analyzer?
The troubleshoot the problem I would first turn on "ip pim sparse-mode"The mode that you are using defaults to "pure dense-mode",if it doesn't find a valid "RP"y.
Then I would check to see if layer 2 snooping is configure on the switch.
Can you confirm that the 3 mention switches are runing at layer3?
Regards

 

[dvtestguy]

Minue,

Yes, we're seeing all 100, even though we've only requested 5.

Traffic source:
Src: 26.0.0.1 - Dest: 238.6.0.3
(Connected to 6506 in access mode for vlan 193).

1) Changed VLAN int 193 from ip pim sparse-dense-mode to ip pim sparse-mode.
interface Vlan193
ip address 10.115.193.5 255.255.255.0
ip pim sparse-mode

Cisco6500IOS#sh ip int vlan 193
Vlan193 is up, line protocol is up
Internet address is 10.115.193.5/24
Broadcast address is 255.255.255.255
Address determined by setup command
MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is disabled
Multicast reserved groups joined: 224.0.0.1 224.0.0.2 224.0.0.22 224.0.0.13
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Local Proxy ARP is disabled
Security level is default
Split horizon is enabled
ICMP redirects are always sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is enabled
IP fast switching on the same interface is disabled
IP Flow switching is disabled
IP CEF switching is enabled
IP Fast switching turbo vector
IP Normal CEF switching turbo vector
IP multicast fast switching is enabled
IP multicast distributed fast switching is disabled
IP route-cache flags are Fast, CEF
Router Discovery is disabled
IP output packet accounting is disabled
IP access violation accounting is disabled
TCP/IP header compression is disabled
RTP/IP header compression is disabled
Probe proxy name replies are disabled
Policy routing is disabled
Network address translation is disabled
WCCP Redirect outbound is disabled
WCCP Redirect inbound is disabled
WCCP Redirect exclude is disabled
BGP Policy Mapping is disabled
IP mls switching is enabled
IP multicast multilayer switching is enabled.


2) Switches connected are snooping...
---------------------------------------------------
Cisco4503IOS#sh ip igmp sn q
Vlan IP Address IGMP Version Port
---------------------------------------------------
193 10.115.193.5 v2 Gi1/20
195 10.115.195.5 v3 Gi1/20
197 10.115.197.5 v3 Gi1/20
410 10.115.41.5 v3 Gi1/20
620 10.115.62.5 v3 Gi1/20

Cisco4503IOS#
Cisco4503IOS#
Cisco4503IOS#sh ip igmp sn ?
groups Show group information
membership Show IGMPv3 host membership information
mrouter Show routers on Catalyst Vlans
querier Show IGMP querier information
vlan Snooping info in a Catalyst Vlan
| Output modifiers
<cr>

Cisco4503IOS#sh ip igmp sn q
Vlan IP Address IGMP Version Port
---------------------------------------------------
193 10.115.193.5 v2 Gi1/20

Cisco4503IOS#sh ip igmp sn g
Vlan Group Version Port List
---------------------------------------------------
Cisco4503IOS#sh ip igmp sn vlan 193
Global IGMP Snooping configuration:
-----------------------------------
IGMP snooping : Enabled
IGMPv3 snooping : Enabled
Report suppression : Enabled
TCN solicit query : Disabled
TCN flood query count : 2

Vlan 193:
--------
IGMP snooping : Enabled
IGMPv2 immediate leave : Disabled
Explicit host tracking : Enabled
Multicast router learning mode : pim-dvmrp
CGMP interoperability mode : IGMP_ONLY

3) Switches are L3 if the VLAN int has an IP confgured and IGMP configs set.

 

[Minue]

Hello
It's a bit difficult to troubleshoot your situation because of the lack of info,config,topology,etc.Anyway being that you are all level 3 make sure that all the interfaces that the mulicast is travelling through has "ip pim sparse-mode"
I have never played around with the 4503 or 4948.Are these running in hybrid or only IOS?Could be something to do with the multicast passing for layer 3 to the layer 2 switch model.
Regards

 

[Minue]

Hello
If you ever resolve the problem,don't forget to let us know.
Regards

 

[dvtestguy]

Minue,

I think we've solved some, but not all the IGMP problems we're seeing.

We've changed the RP to the 6506, and also found that our traffic source MAC address started out as "00", not "01" for M-Cast. Once we changed both, IGMP seems to now work, but now seeing the 4948 & 4503 switches pegged at 87%-95% utilization.
Cisco4948#sh proc cpu | i Cat4k Mgmt LoPri
36 2746138604 829787145 3309 88.63% 87.14% 87.21% 0 Cat4k Mgmt LoPri

Any ideas why this would happen?

Thanks

 

[ADB100]

What is the TTL of the traffic? I remember if its 1 then it is sent to the CPU and gets handled in software and it they are high-bandwidth streams it eats at the CPU.

Andy

 

[dvtestguy]

ADB100,

TTL is set at 10 on the traffic source.