IGMP Snooping

[6gnet]

Does IGMP snooping actually work ? Here's the test setup:

IPTV Client (igmp v3) -> Netonix WS-6-MINI -> Juniper switch

Managment VLAN is 105 (tagged on all ports), IPTV vlan is 111 untagged on all ports.

Scenario 1: IGMP snooping disabled on Netonix, IPTV client works correctly however multicast traffic goes to all interfaces

Scenario 2: IGMP snooping enabled on Netonix, IPTV client sends IGMP packets, no IGMP is received on the Juniper switch, multicast does not work.


Is there any way (commands, web gui etc) I can see what IGMP snooping is doing on the switch ?

-G

[Eric Stern]

It works in my lab. However, I generally only test on VLAN 1 so there might be an incompatibility when using other VLANs. Although the testing I did today does indicate it works fine with VLANs as well. I'm using VLC for testing.

Can I get a screenshot of your VLAN tab?

[6gnet]

How can I send you the screenshot ?

I have 3 vlans:

ID Enable Description 1 2 3 4 5 6
---- ------ ----------- -- -- -- -- -- --
105 true Management T T T T T T
111 true bsx-waw2 U U U U U U
104 true 6gnet-office T T T T T T

Port 1 is an ubnt bridge, port 2 is an IPTV box.
Connecting IPTV box directly to the ubnt bridge works perfectly.
Connecting with the switch there are 2 situations:
1. IGMP-snooping disabled: multicast works but goes to all ports (normal)
2. IGMP-snooping enabled: multicast does not work for a long while, sometimes after few minutes start working, BUT it's acting like igmp-snooping is not enabled: multicast goes to all ports. Sniffing packets on both ports, I can see igmp packets from IPTV box going towards the switch but never reaching the UBNT bridge and vice versa.

-G

[Eric Stern]

You can attach a screenshot to your post by using the "Upload attachment" feature below, its next to "Options". Once the attachment is uploaded it will show up in the "Posted attachments" below.

[6gnet]

Here's the screenshot. As I wrote before with IGMP snooping disabled, multicast works but goes to all ports. Enabling IGMP snooping stops multicast from working for first few minutes, after few minutes (not always) it behaves as if IGMP snooping was disabled and traffic goes to all ports....

We're building an ethernet network in a 30 apartment building with 12 port switches and really need to get it to work to support IPTV...

-Gregg

[6gnet]

Any update on this issue ?

-Gregg

[sirhc]

As I wrote before with IGMP snooping disabled, multicast works but goes to all ports.

And this is exactly how multicast should work, not sure whats wrong?

Enabling IGMP snooping stops multicast from working for first few minutes, after few minutes (not always) it behaves as if IGMP snooping was disabled and traffic goes to all ports....

I have very limited ways to test IGMP at my WISP but when I tested it IGMP worked as intended.

Has anyone else here tested IGMP?

I will ping Eric on it again.

[6gnet]

FYI: I've tested this on 1.3.8 through latest 1.4.x version and the behavior is the same on all version, are there any CLI or shell commands that I can use to see what IGMP is doing ?

I did not see any igmp process in process list in shell either..

[Eric Stern]

FYI: I've tested this on 1.3.8 through latest 1.4.x version and the behavior is the same on all version, are there any CLI or shell commands that I can use to see what IGMP is doing ?

Not at this time.

I did not see any igmp process in process list in shell either..

IGMP snooping is part of the vtss_appl process.

If you can describe a test setup (as simple as possible) that demonstrates the problem I can try it in my lab and see if I can figure out what is going on.

[6gnet]

by multicast flooding to all ports I simply confirm that multicast works as expected with IGMP snooping is turned off

The setup is quite simple:

Multicast Server -> Juniper router -> Netonix switch -> IPTV box or laptop

Port 1 connected to a Juniper router , 802.1q tagged vlans:
105 - managment only
121 - internet (data)
122 - IPTV

IPTV settop box or laptop with VLC box connected to port 3 (untagged for vlan 122)

Tried also:
multicast source (Linux, iperf) -> vlan122 (tagged) -> Port 1 of Netonix then Laptop to port 3 (untagged vlan 122, iperf). Even in this setup I did not see any IGMP queries coming from Netonix switch and with IGMP snooping enabled, there was no multicast passing through the switch for quite few minutes, once multicast started getting through, it would go to all ports connected on the switch (even though IGMP snooping would mean it should not..)

-Gregg