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BGP and Cat3850 problem

have a Cat3850 running Ver 03.03.03SE IP Services.

configured BGP to per with one of the Internet providers and the pering is working as expected except that we want to send out two sets of routes with the second set having a higher AS path.  I have it configured like an older 3900 router.  Looks like it is hitting the first route-map and then not bothering with the second.  What am I missing?

here is what we are doing:

route-map To-Provider permit 10
 match ip address prefix-list BGP-Out
!
route-map To-Provider permit 20
 match ip address prefix-list BGP-Out2
 set as-path prepend xxxx xxxx xxxx

Thoughts?

1 Accepted Solution

Accepted Solutions

This doc shows that it is supported bit conflicting , looks like it was only introduced in later IOS-XE , have you tried to match it by access-list in case its a bug

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-3se/3850/irg-xe-3se-3850-book/irg-oubound-route-filtering.html#GUID-2E4DD94D-AD40-4D96-B01A-273154292568

View solution in original post

10 Replies 10

Mark Malone
VIP Alumni
VIP Alumni

hmm I think not a 100% on this but from what i remember switches even in ipservices cant do full pbr like a 3900 router

says below that 3850s only support set ip next hop only in pbr

Only set ip next-hop command can be used under route-map configuration mode when you configure policy-based routing.

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_pi/configuration/xe-3se/3850/iri-xe-3se-3850-book/iri-pbr.html

According to the Data Sheet, with IP Services we can do full BGP4

This is BGP Advertized Routes are not happening the way they should

Yes bgp is supported but this ----set as-path prepend is not under pbr from the doc only set ip next hop is , your problem is the 2nd route-maps not working right ? Not a bgp issue

This doc shows that it is supported bit conflicting , looks like it was only introduced in later IOS-XE , have you tried to match it by access-list in case its a bug

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-3se/3850/irg-xe-3se-3850-book/irg-oubound-route-filtering.html#GUID-2E4DD94D-AD40-4D96-B01A-273154292568

Mark,

that seems to have helpd but is not complete list. 

In the example I see

router bgp 65100

network aaa.aaa.aa.0

network bbb.bbb.b.0

I do not have these lines currently.  Do I need to all all of those networks I want to announce to the upstream provider so that it all will work?

If there local networks that need to be advertised and influenced out then yes they should be in your BGP process as network statements , if there not in the table they cant manipulated for upstream purposes

Looks like we are all set  access-list number worked  named did not.

Thanks.

ah that's good they really need to specify exactly what way its supported in the docs per platform

Right,

The first route-map that indicates which networks I want to announce with a standard path is working but the second route-map that has the other networks with the set as-prepend is not sending the additional routes.  And that is the problem. 

So while the 3850 takes the command is is ignoring it entirely. 

Do you have a suggestion on a different comand to announce the other routes but with a higher cost?

Not really without altering all routes on 1 link, without the ability to use all set commands under route-map you cannot use any of the metrics to alter a block of routes , the only other way is to do it at the neighbour level which alters all coming from it or out

Your image is showing it as supported for outbound policy support but does not say for what conditions , its an ED release so you could try the 3.6.3 MD which is the safe harbour recommended version , that will rule it out as being specific to that software release but id say its a limitation to the switch itself

did the logs throw up any errors like --%PLATFORM_PBR-3-UNSUPPORTED_RMAP

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