Triple redundancy link

Hi, community!I have some problem with configuration redundancy on my switch. I need to set to links as a redundancy. I have links A,B,C. A is a main link whose redundancy link is B. If A and B failed i want to that link C take whole network traffic. I don't have any idea how to do this.

Thanks for help
Best regards.

12 replies

Userlevel 6
Please clarify if you are referring to routing and you play with the link cost or if you want L2 and you want to play with spantree...
Why don't you just setup a 3 port LAG?
Userlevel 6
If each link is full duplex and the same speed then agree the LAG is the best choice.
Userlevel 2
Spanning tree will take care of this automatically BUT I also recommend a 3 port LAG.
Yeah, sorry and thank you all ,it is on L2, and the network is connected with EAPS, so without STP. And yes all the links are in full duplex with the same speed. But if i make a 3 port LAG, data will be balanced equal on each port and i want to use only A(if works)
only B(if A failed) and only C(if A and B failed). Am i right ?

Userlevel 6
Yes you are right. In such case you need to use scripting to react on link A event. If link A goes down then configure EAPS to use link B and deconfigure vlans from link A. If link A goes up again then deconfigure link B and configure link A... With LAG there will not be outage. With the scripting approach there will be some shotr outage as script must execute and EAPs must be established again. But yes doable.
Thank you all
Userlevel 6
There may be other ways to do what you are trying to do ... It would help if we had a simple diagram show switches and what ABC is connected to.
I configure it by UPM profile, but i have problem with if statment

configure upm timer "timer" after 10 every 10

enable lldp ports all

conf lldp ports 1 2 advertise all-tlvs

conf upm event device-detect profile "redundancy" ports 1 2

conf upm event device-undetect profile "redundancy" ports 1 2

create upm profile redundancy:


enable port 3


disable port 3


but this if always disable port
Userlevel 2
How about this solution?
It's good for two links but you can't set third link as a redundancy to first two
Userlevel 2
Ok, guess I didn't have the full picture. Probably as Etherman suggested a simple diagram would be helpful.