Really strange problem with AB ENET card.

[imloggedin]

Just a side note, IGMP snooping does NOT mean a managed switch.
N-tron sells non managed switches with IGMP snooping.

cool. thanks for sharing the find.

 

[dash]

Just a side note, IGMP snooping does NOT mean a managed switch.
N-tron sells non managed switches with IGMP snooping.

Which unit are you referring to? The lowest level switch I am aware of is the 500 series with the Advanced Firmware option, which basically makes it a managed switch.

If you can get it on a unit without that option I have been spending more than I have to.

Darren

 

[Operaghost]

Be carefel here.

Just because a non-managed switch "supports" IGMP snooping does not mean that it can "implement" IGMP snooping. It's like owning a telephone. It doesn't do me much good if all I can do is listen to other people's calls but not receive or make my own calls.

You need a device, typically a router or a layer 3 switch to "place the call" so that we can learn where all members of the multicast group are located. Once that is learned, then the "supporting" layer 2 switch can use IGMP snooping. So look for a device that can perform the "query" or "join". If you dig into the settings on your switch and don't see an option for a timeout on IGMP, then your device probably cannot do the query function and thus cannot implement IGMP snooping, only support it.

OG

 

[Ken Roach]

Fun with IGMP protocol

I was recently doing some seminars with the new midrange A-B "Stratix" switches, which are 4 or 8 port managed switches that have the usual IGMP Snooping+Querier and other management features as well as some integration into Logix 5000.

I was doing a little protocol sniffing to help a customer understand the origin of ARP probes that he was seeing on his network (many A-B products repeatedly probe for duplicate IP addresses), and learned that the Stratix switches broadcast an IGMP membership query immediately upon a link being plugged in. They also do so periodically, but it was interesting to visualize the delay between the IGMP membership query and the ARP probes, which you can attribute to the time the device spends connecting to the network.

That's an important feature. If the switch (or router) that is behaving as the IGMP Querier only sends out periodic queries, then the network might see unconstrained multicast data for quite a while (several minutes ?) until another IGMP Membership Query gets sent.

I just received an HP Procurve 2524 switch to test a customer's setup in which he has a bunch of I/O devices that fail when this switch, which serves only as a WAN uplink to his I/O switch, gets power cycled. Time to start reading user manuals.

 

[CroCop]

I was recently doing some seminars with the new midrange A-B "Stratix" switches, which are 4 or 8 port managed switches that have the usual IGMP Snooping+Querier and other management features as well as some integration into Logix 5000.

I was doing a little protocol sniffing to help a customer understand the origin of ARP probes that he was seeing on his network (many A-B products repeatedly probe for duplicate IP addresses), and learned that the Stratix switches broadcast an IGMP membership query immediately upon a link being plugged in. They also do so periodically, but it was interesting to visualize the delay between the IGMP membership query and the ARP probes, which you can attribute to the time the device spends connecting to the network.

That's an important feature. If the switch (or router) that is behaving as the IGMP Querier only sends out periodic queries, then the network might see unconstrained multicast data for quite a while (several minutes ?) until another IGMP Membership Query gets sent.

I just received an HP Procurve 2524 switch to test a customer's setup in which he has a bunch of I/O devices that fail when this switch, which serves only as a WAN uplink to his I/O switch, gets power cycled. Time to start reading user manuals.

Do you have link to the Stratix switch?

Is it available to the general public?

 

[1_1_1]

just go to e-bay and get a cisco 2924m-xl
its an EOL model but its a great switch for the money

I've actualy got a spare 2924m-xl sitting in front of me that I would be willing to part with for $50 or so

what I'd try is if you get some managed switches then put all the PLC's in a vlan that can't reach the router unless theres some need for them to