Where I can find info for "bgp bestpath as-path multipath-relax"

[frank]

Where can I find info for a hidden command "bgp bestpath as-path multipath-relax".

Client is asking if we can use this command to load balance between two MPLS carriers but can't find any info from CCO.

[JORGE RODRIGUEZ]

did you try this link

http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_feature_guide09186a00800b5d5f.html

[frank]

Yes I've checked this page but can't find the "bgp bestpath as-path multipath-relax" command that the client was asking for?

What exactly this command do?

[mohammedmahmoud]

Hi,

This will allow the router to load-share across multiple BGP paths even if the as-path is different.

HTH,

Mohammed Mahmoud.

[frank]

Thanks,

But what are the criterias I can use to control the load share? Is it at CE side or PE side?

Can you provide a link for detail?

[mohammedmahmoud]

Hi,

To load share over multiple eBGP routes, the routes must be equal-cost paths with identical BGP attributes (same Weight, Local-Pref, AS-Path, Origin and MED and different next-hop - Even the AS_PATH should match (entire attribute and not just length), and here comes the job of this command to alter the AS_PATH part.

HTH,

Mohammed Mahmoud.

[frank]

In this case if I setup "maximum-path" then it will do the same thing why do I want to use "bgp bestpath as-path multipath-relax"?

[mohammedmahmoud]

Hi Frank,

No, you'll have to use the maximum-path to do load sharing any way, but when using this command the load sharing will accept multiple paths with different AS_PATH which is not the normal case.

HTH,

Mohammed Mahmoud.

[frank]

Ok, Thanks.

Is there any document for this command?

[seekianherng]

hi,

Previously, i posted the same question regarding "bgp bestpath as-path multipath-relax". Seems to work under dynampis simulator.

http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Network%20Infrastructure&topic=WAN%2C%20Routing%20and%20Switching&CommCmd=MB%3Fcmd%3Dpass_through%26location%3Doutline%40%5E1%40%40.1ddead38

[adfsdafs adsfafds]

I know this is really old, but what is the current status for this command? I can't find it in IOS documentation (but found one in NX-OS). On IOS 12.5, it's hidden (not shown with ?) but I can enter it without error. However it does not seem to do anything...

[Harold Ritter]

Hi,

Even though this is a hidden command, I know many  customers using it. Make sure you also configure "maximum-paths" for the  "bgp bestpath as-path multipath-relax" to take effect.

Regards