ELRP with dynamically changing vlan membership

[EtherNation_Use]

Create Date: Mar 13 2013 9:48PM

Hello Everyone,

I've been looking at ELRP to help prevent L2 loops. Our switches (one section of them) work in conjunction with Bradford NAC system, which based on the user's profile and settings, puts the edge port into either production vlan or registration or quarantine (non-production) vlans. ELRP if I understand correctly works per vlan only, right? For instance looping a edge port in production vlan with a an edge port in the non-production vlan will not cause either of the edge ports to shutdown, right? My final goal is to achieve prevent L2 loops when the vlan membership of an edge port is constantly changing.

Is there anyway to tweak this behavior of ELRP and if not, are there any alternatives to what I'm trying to achieve?

Thanks!
(from Shashank_S Kumar)

[EtherNation_Use]

Create Date: Mar 19 2013 9:31PM

Hey Prusso,

Yes, the netgear unmanaged switched presumably all ports untagged on the same vlan. The control-elrp vlan is tagged on all ports with elrp enabled. This is because in the live network, the Bradford NAC device constantly moves ports untagged in various vlans - production, registration, housing, etc. My test switch is setup to mimic the live environment.

My comment about control-vlan and default vlan is that I tried untagging control-elrp on a port, say port 24, tried looping it with a remote loop on netgear and observed elrp not catching the loop. Next I removed control-elrp from port 24 and untagged port 24 with the default vlan under the assumption that the remote netgear probably also passes traffic untagged/default/native to my XOS switch. Even in this scenario, elrp did not catch the loop and did not disable port 24.
Confusing, but hope it makes sense ? 🙂
The firmware we are using is 12.5.1.6 on the primary (active) partition and 12.3.3.6 on the secondary.

Attaching the configuration as requested.
Also attaching the XOS message decoder since I mentioned it earlier.

Btw, I greatly appreciate you taking the time and effort to answer my questions and help me.
Thanks!

Unable to attach files to ethernation.
Please download them here:
http://wikisend.com/download/708340/config-elrp.txt
http://wikisend.com/download/276684/EXOS-messages-200906.pdf

(from Shashank_S Kumar)

[EtherNation_Use]

Create Date: Mar 19 2013 7:27PM

Hey Skumar

So the netgear has all ports untagged and in the same VLAN correct? You then take one port on the switch and assign the control-vlan to that port untagged with ELRP enabled on that port Correct? That should work without any issue. What I don't understand is the comment that you add the default to the port untagged. Are you saying that you removed the control-VLAN then added the default VLAN? You can not have to untagged VLANs on a port.

Can you please do the following commands and post the output of the config here for me to test?
Disable CLIP < this just disables the cli paging so you wont have to hit the space bar.


type show config.

After you have the file upload it to the post. You can then enable clip.

Thanks
P

Also what version of code are you running? (from Paul_Russo)

[EtherNation_Use]

Create Date: Mar 18 2013 4:12PM

Hey Prusso,

The remote switch is unmanaged netgrear switch for home use.
I configured a port with untag control-elrp vlan and after that added the default vlan untagged to the same port. ELRP did not detect loops in both the instances.
I was wondering, since the ELRP transmit counter is increasing, if there would be a way to detect these specific ELRP transmit logs and wire a UPM for it? Would you happen to have or know where I could find a message decoder - similar to the one that's available for ExtremeWare? (from Shashank_S Kumar)

[EtherNation_Use]

Create Date: Mar 16 2013 11:12PM

Hey skumar

this came across a little off but I see the packets that are transmitted but none received which means that the switch isn't getting them back. Is the remote switch tagged for this VLAN?

If Default is untagged on this port try it with the untagged VLAN.

P (from Paul_Russo)

[EtherNation_Use]

Create Date: Mar 15 2013 5:31PM

Hey Prusso,

With a remote looped switch plugged in my XOS switch, I see that the ELRP counters are increasing, but no action seems to be taken.
The packets received counter is not increasing though.

* X250e-24p.16 # sh elrp

ELRP Standalone Client: Enabled

Number of ELRP sessions: 1
Number of ELRP pkts transmitted: 92
Number of ELRP pkts received: 0

Pkts Pkts Disable
Client Vlan Ports Int. Count Cyclic Xmit Rcvd Action Port (sec)
--------------------------------------------------------------------------------
CLI control-elrp 1-24 1 0 Yes 92 0 LT Perm
--------------------------------------------------------------------------------
Action : (P) Print , (L) Log , (T) Trap , (C) Callback
(from Shashank_S Kumar)