I have a scenario where I have a primary DS-3 with a Shadow DS-3 as the backup. The Shadow DS-3 is only to be used in the event the primary fails, so we are manually setting the MED to poison the path through the Shadow DS-3. This works fine as a backup solution, but it is now requested that the Shadow DS-3 be active in the event that the primary hits a certain bandwidth usage. Kind of like setting the threshold on an ISDN line, but I don't think that this is possible. I've search CCO, but I haven't had much luck. I spoke with the ISP and they don't think it is possible either.
I am just wanting to verify my thinking on this before I go to the people wanting this functionality and tell them that it is not possible.
I believe there's no way to achieve that through BGP.
However You can do it locally between your site and your ISP: either using backup threshold (if both links terminate at same router both ends), or by using and tweaking some IGP that use load metric and variance in the routing decision (EIGRP?) between you and the ISP (underneath your BGP).
The only problem is that these links go to different locations, and I'm not sure if UUNET will be want to configure EIGRP on these links. They don't want to do any load balancing because they don't want traffic to flow across the Shadow DS-3 unless there is an outage, or in the event that the primary DS-3 becomes saturated.
I think I will just have to let them know it can't be accomplished while maintaining their original requirements. The cost of the Shadow DS-3 is based on how much traffic goes across it. Hence, they don't want to use it unless they have to.
I appreciate your comments and if you can think of another way to accomplish this post it on the board!
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.