topic RE: redundant link in ExtremeSwitching (EXOS/Switch Engine)

redundant link

Mohammed_Jashee — Thu, 05 Nov 2015 11:38:00 GMT

Hi All...
am trying to configure a redundant link between my Core switch to distribution switch.
below am attached the link layout. Am trying to enable STP its showing below error.

(Rack-SW.2 # enable stp "s0"

Error: Incorrect carrier vlan configuration of port 23-24 in stp domain s0
HP_Rack-SW.3 #)

Kindly suggest any best way to achieve the requirement

RE: redundant link

Prashanth_KG — Thu, 05 Nov 2015 12:02:00 GMT

Hi Mohammed,

The below article would help you get rid of the error. If the domain s0 is operating in dot1d mode and the ports are tagged, then the error would pop up. Also, if the s0 is operating in dot1w mode and the ports are untagged, the error would pop up. We need to ensure that the VLAN of the STP tag is added in these ports as tagged.

https://gtacknowledge.extremenetworks.com/articles/Q_A/Error-Incorrect-carrier-vlan-configuration-of-port-port-in-stp-domain-STP-Domain

I am assuming both are exreme switches.
If you are only planning to establish redundancy with 2 active links going to the core switch and not requiring the STP on the other links, following are the other options that you could explore apart from STP.

- Software redundant port

This would have one link as active and the other link would become active in case of the first link failure.
https://gtacknowledge.extremenetworks.com/articles/Q_A/How-to-validate-if-a-software-controlled-redundant-port-is-set-up-to-block-traffic

- If both the ports are of same speed and duplex, you could also explore the option of enabling load sharing. This will give you both the redundancy and efficient bandwidth usage.

https://gtacknowledge.extremenetworks.com/articles/How_To/how-to-configure-sharing-LAG-LACP-in-Summit-stack-or-BlackDiamond-switches

Hope this helps!

RE: redundant link

Shannon_Rowe — Thu, 05 Nov 2015 12:02:00 GMT

I am getting this same error, switch is in dot1w mode, all ports are tagged with vlan xyz. I do not want to add an untagged vlan to all ports just to make this work, and certainly have not had to do this on other switches. which also have no untagged vlans on the ports.

Anyone have any other suggestions or troubleshooting tips, the Q_A article really does not help that much.

RE: redundant link

Prashanth_KG — Thu, 05 Nov 2015 12:02:00 GMT

Hi Shannon,

Try changing the default stpd mode of these ports to other than dot1d. If it is dot1d, the ports should have an untagged vlan.

configure stpd ports mode

Hope this helps!

RE: redundant link

Bill_Stritzinge — Thu, 17 Dec 2015 09:52:00 GMT

I would suggest an EAPS ring for this ... easy ..

RE: redundant link

Bill_Stritzinge — Thu, 17 Dec 2015 18:50:00 GMT

Easy EAPS configuration with no spanning tree hassle.... will work much better!

Switch1

create eaps ring1
create vlan control1 tag 2000
conf control1 add port 23,24 tag
configure ring1 add control control1
configure ring1 add primary port 23
configure ring1 add secondary port 24
configure ring1 mode master
configure ring1 add protected vlan vlan1
configure ring1 add protected vlan vlan2
configure ring1 add protected vlan vlan3
enable eaps
enable ring1

Switch2

create eaps ring1
create vlan control1 tag 2000
conf control1 add port 23,24 tag
configure ring1 add control control1
configure ring1 add primary port 23
configure ring1 add secondary port 24
configure ring1 mode transit
configure ring1 add protected vlan vlan1
configure ring1 add protected vlan vlan2
configure ring1 add protected vlan vlan3
enable eaps
enable ring1

The only other thing you need is to add port 23,24 tagged to each vlan and remove ALL STP configuration..

Hope this helps...

Bill

RE: redundant link

dflouret — Thu, 17 Dec 2015 21:37:00 GMT

Dumb question... Why don't you just create a LAG with the two links? Much simpler than STP and EAPS and better performance since both links would be active simultaneously.

RE: redundant link

Shannon_Rowe — Fri, 18 Dec 2015 01:33:00 GMT

Thanks all those are all really helpful suggestions. Yes in this instance i have ended up trunking (LAG) the two links and just left STP off. But I seem to come across this issue/behaviour quite often so thought I would post.

In future I will also look into using emistp port mode, and changing our standard and using EAPS.