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New Member

SG500 Multicast-TV

I am trying to get multicast across VLANs working on my SG500 and since it doesn't have PIM, I think the Multicast-TV option can work.

However, now my clients are getting switched to the Multicast-TV VLAN instead of the regular VLAN they are assigned.

Example:

ip igmp snooping vlan 10 multicast-tv 234.5.6.7

ip igmp snooping vlan 10 multicast-tv 239.192.4.237

ip igmp snooping vlan 10 multicast-tv 239.255.250.250

ip igmp snooping vlan 10 multicast-tv 239.255.255.250

ip igmp snooping vlan 100 multicast-tv 234.5.6.7

ip igmp snooping vlan 100 multicast-tv 239.192.4.237

ip igmp snooping vlan 100 multicast-tv 239.255.250.250

ip igmp snooping vlan 100 multicast-tv 239.255.255.250

interface gigabitethernet1/1/32

description "VLAN 100 - Client"

service-acl input "Access Port Security IPv4" "Access Port Security IPv6"

switchport mode access

switchport access vlan 100

switchport access multicast-tv vlan 10

interface Port-channel1

description "VLAN 10 - Alpha"

switchport mode access

switchport access vlan 10

switchport access multicast-tv vlan 100

Now, the client on VLAN 100 has unexpectedly gotten a DHCP address from VLAN 10 and is unable to access anything outside VLAN 10.

  • Small Business Switches
6 REPLIES
Green

SG500 Multicast-TV

Hey Fratiani, may be these posts help some

https://supportforums.cisco.com/thread/2187693

https://supportforums.cisco.com/thread/2260535

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

SG500 Multicast-TV

Hi Tom,

Unfortunately those posts don't really help me much.

They also don't explain why my one host magically jumped VLANs.

I suppose there is no chance that this, or any SMB, product will ever get PIM?

Thanks,

D

Green

SG500 Multicast-TV

Hi Fratiani, I do not think PIM will be implemented any time soon since that would align the switches to compete too much with Catalyst.

I guess I had misunderstood your post, I didn't realize there was bleedover. But I think in the scenario with Multicast TV VLAN such behavior is expected. The Multicast TV VLAN allows traffic to join different multi VLAN that are not on the same data VLAN. In addition, the multicast TV VLAN information is untagged when it traverses the trunk (egress port).

From what I can tell you have VLAN 10 and 100 both as untag packet which it probably is not discerning.

So basically taking a guess, you are saying that if a IGMP message is received on lets say VLAN 100, it is changing to VLAN 10? The IGMP is forcing join over an unexpected VLAN?

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

SG500 Multicast-TV

I'm really just trying to multicast over VLANs.

I thought this tech included in these switches called Multicast-TV, could be used to bridge this gap somewhat.

I just want an untaged multicast server on VLAN 10 to multicast to an untaged client on VLAN 100.

It is completely unreasonable for the client on VLAN 100 to be silently switched to another VLAN and left with no communication outside that VLAN.

I also did not get that impression when I was attempting to understand this technology from the Admin Guide.

What happened was I started a server on VLAN 10.

Then started a client on VLAN 100.

Nothing worked...

Stopped and started the server and client a few times and it started to work.

Little did I know my client was magically switch to VLAN 10.

Removed the "switchport access multicast-tv" statements and rebooted the clients.

Back to normal.

New Member

SG500 Multicast-TV

After a lot of more testing I think I got this one figured out.

I was trying to cheat the system by adding both sides to opposite MCast-TV VLANs.

My thought process was to allow MCast communication manually between the two VLANs.

This does not work.

You can only add one side to the MCast-TV VLAN.

It is still not perfect as unicast transmissions to the server on VLAN 10 are temporarily interrupted when MCast transmissions are established between VLANs.

Example:

Server on VLAN 10 acting as MCast server.

Add clients on VLAN 100 to MCast-TV VLAN 10.

Does NOT work example:

Server on VLAN 10 acting as MCast server.

Add clients on VLAN 100 to MCast-TV VLAN 10.

Add server on VLAN 10 to MCast-TV VLAN 100.

New Member

SG500 Multicast-TV

After even more testing...

This feature is VERY broken.

Even working as my last example, this feature tends to break all unicast traffic on the network.

Removing "switchport access multicast-tv vlan 10" and rebooting the switch makes things work again.

Do NOT use the Multicast-TV feature on these switches, you will be pulling your hair out wondering why IPv4/IPv6 connectivity is spotty at best.

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