Hi Phil,

So VLACP is just a Layer 2 heartbeat to detect path failures… you should leave VLACP out of the mix until you have the MLT/SMLT configuration setup and working properly.

Good Luck!

I assume this will work ? Do I then create an MLT for the relavant ports ( 2 MLT’s that contain the ports in the VLACP ?

Hi,

You question isn’t really on-topic with respect to VLACP. Please post any additional questions over one the discussion forums.

When you set the speed to 100 you disable auto-negotiation. If you are trying to set the speed to auto and the duplex to full you need to research CANA (Customizable Auto-negotiation Advertisements) which is only available in certain switch models running specific software releases.

If you want true auto-negotiation, then set the speed to auto and the duplex to auto.

Good Luck!

#config t
(config)t#interface fastethernet 32
(config-if)#speed 100
(config-if)#duplex auto

But auto – negotiation showing disabled only. please help how to enabled auto negotiation.

Hi Jayne,

VLACP is a Nortel/Avaya proprietary protocol. It won’t work with Cisco equipment. VLACP will only work between Nortel/Avaya switches.

Good Luck!

Did you manage to enable VLACP on Cisco switches? Do you mind sharing your experience?

By the way, I’m going to do a lab test on VLACP features and my setup looks something like this:-

Site A: Cisco Cat6509 Switch -> Safenet Layer-2 Ethernet Encryptor -> BTI Switch_A -> WAN link to Site B
Site B: Cisco Cat6509 Switch -> Safenet Layer-2 Ethernet Encryptor -> BTI Switch_B -> WAN link to Site A

Should I enable/configure VLACP in all switches residing at Sites A & B? With the encryptor in place, will it block VLACP updates between both sites?

Thanks for taking the time to comment.

We’ve been using SMLT for quite sometime now and it’s worked extremely well. Unfortunately due to Nortel’s situation I’m now working with Cisco Nexus 7010 switch and vPC (Virtual Port Channel).

I am an ex-Nortel IT employee with SMLT experience. We replaced out Accelar 1200’s in the Alpharetta campus with one ERS8600 (then Passport) and later added a second creating an SMLT/IST access L3/L2 core with MLT’s to access L2 (BS460) in the closets. It was great! At first.

Then we had to problem with single fiber failure. Everything worked for about 24-48 while a storm built up to the point it shut down both switches. I enjoyed driving into the office at 1 AM to replace a GBIC or pull a fiber patch and reboot the 8600’s. (not!) SFFD fixed the problem and allowed me to sleep better. Network services didn’t implement VLACP until after I got laid of in 2007.

SMLT was the greatest thing since sliced bread. We could upgrade one switch and reboot without missing a lick. I just hope Avaya appreciates the technology they got from Nortel and develops it further.

Hi Remy,

I would strongly advise you to review the release notes of 4.1.8.3 and/or 5.1.1 depending on which version you chose to upgrade to. I will point out that 5.1 and 5.1.1 where pulled from Nortel’s website in place of 5.1.1.1 (I suspect there was a pretty significant problem although the release notes didn’t really give any hints).

If you are seriously contemplating 5.x software you should make sure that you don’t have any un-supported hardware in your switch like non-E cards or 8690SFs. I should also warn you that 4.1.8.x and 5.x work the CPUs much harder than previous software releases as such you can expect to see an increase in CPU utilization.

If you’re using VRRP you’ll also need to make sure that you have unique VRRP IDs across the entire switch.

Good Luck!

Many thanks for your answer ! You’re right, my VLACP configuration is exactly what Nortel recommends (500 ms short timers and a timeout scale fixed at 5).

From my point of view, I also think that the version code of my 8600 is obsolete, and I need to upgrade it as soon as possible. What do you think about the 5.x versions recently released for 8600 ?

Regarding the CPU utilization, I will monitor it in the aim to check if there is any link with these VLACP flap.

Have a nice day !

Hi Remy,

Thanks for the thoughtful words!

There were a lot of known issues with VLACP flapping back in the early software code for the ERS 8600 and ERS 5500 series. While the software you are are running on the ERS 5520 is fairly reliable (5.1) I would suggest that you upgrade the software on your ERS 8600 to 4.1.8.3. VLACP can also be impacted by how busy your CPU is (and which model of CPU you have) and how many software features you have enabled on your ERS 8600 switch.

I’m going to assume that you have configured VLACP with short timers (value of 500ms) and a retry of 5 which Nortel now recommends.

Cheers!

First of all, congratulations for your blog, its content is very useful and interesting. I use VLACP between Nortel 8610 and Nortel 5520, and there is some issue that I can’t explain. Despite the fact I have followed Nortel’s recommendation regarding the last workaround between these two devices (especially with the timeout scale to modify), my VLACP seems to do like “link flap” sometimes. I run SMLT over this layer and one of the two ports concerned by this process is put down by VLACP without any reason (no link or transceiver failure …)

I will communicate you the firmware versions used on each device later (by memory, 5.1 for 5520 and a old release for 8610 like 4.1.2 i think), but did you already face to this kind of issue ?

Many thanks for your help and keep your blog as it is :-)

Remy

Your touching on a few different limitations and design considerations in your comment.

In the example we are using “short timers” so yes I would agree with you that short timers should be used. You are correct that the default timers between the ERS 8600 and ERS 5500 series don’t match. The example provided specifically configures the VLACP timeout to 500ms.

I don’t actually use HA-mode on the ERS 8600 switch although I have many switches with dual 8692SFs that also have SuperMezz daughter cards installed on them. There are quite a few limitations with the HA-mode configuration including a number of unsupported protocols, one being BGP.

Thanks for the post.

Cheers!

– to be efficient, you need to use “short timers” (<10s), but this mode is currently incompatible with HA-mode (high-availability with 2 CPU cards).
This limitation is apparently global to HA-mode (unless you use SuperMezz), which doesn’t support short timers on any protocol (there’s a few seconds blackout when CPU failover occurs).

– VLACP implementation differs on ERS 8600 and 5500. When you plug-in a SMLT link, all traffic sent from the 5510 to the 8600 is dropped during the VLACP timer.
If you use the long timer, you lost packets for at least 10s…