Cisco equivalent cli command - local-preference add #

[fsebera]

We are migrating our global wan core routers from Juniper to Cisco. We have extensive and complex policy based TE configurations. One of the Juniper BGP policy statements uses the local-preference add # option. I cannot seem to find an equivalent route-map set local-preference option in the Cisco IOS. The option in IOS to set a LP value exist but no option to add to the current LP value. The policy needs to accept the current ingress LP value and then increase that LP value by a certain amount based on the matched community.

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How this BGP policy works:

The core router receives prefixes from iBGP neighbors, prefixes matching a specific community, the policy increases the LP value.

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Sadly, time is always short and rushed so I have not had the time to figured out how this increased LP value affects or effects the global net. Any ideas with the BGP LP value increase would be greatly appreciated.

Thanks

Frank 

[Giuseppe Larosa]

Hello Frank,

You can match on BGP community and then you can set the local-preference to a value like 100 + 4*<increase>.

As the default BGP local preference is 100, and the highest value is preferred, all you can do is to try to set a local preference value to an higher value as an approximation.

Hope to help

Giuseppe

[fsebera]

Are you indicating Cisco IOS cannot examine the current Local-Preference value and ADD to that existing LP value but can only set some new predetermined value?

Thanks

Frank

[Giuseppe Larosa]

Hello Frank,

I don't know what type of Cisco platform you are installing in your network.

I have checked also the IOS XR routing policy configuration guide for ASR 9000

see

https://content.cisco.com/chapter.sjs?uri=/searchable/chapter/content/en/us/td/docs/routers/asr9000/software/asr9k-r6-4/routing/configuration/guide/b-routing-cg-asr9000-64x/b-routing-cg-asr9000-64x_chapter_01011.html.xml&searchurl=https%3A%2F%2Fsearc...

The table provides the capability to match on local preference using is, ge, le or eq but only set option

local-preference

is, ge, le, eq

set

Hope to help

Giuseppe

[fsebera]

We are migrating to the new IOS-XE platform, ASR1009.

I guess at this point, I will be forced to stop the migration effort and figure out what the Juniper ADD function is actually providing.

Didn't think there would be so much thinking in this task - LOL

Thank you for your efforts

Frank

[fsebera]

followup

I know my messages seemed like I didn't want to understand how my networking policies actually worked - Let me assure folks that this is not the case. The real issue is each router config is several hundred pages long (and that's with size 8 font) and we have many hundreds of routers across the world. We have many many many TE PBR policies that are extremely complex - and sadly the time table to migrate is not getting any extensions. Long story story - Juniper has a feature to apply a logging function to a policy that shows which prefix is hitting which policy and which line in the policy is hit or bypassed and log it all to a file(s). This file can be off loaded and then be analyzed dynamically. The Juniper logging feature is much like Cisco's ACL log feature but more robust as it records the details to a separate file. Very Nice!!

Anyway, I have shipped this research task down to the tier 3 support folks for analysis!

Thanks for the assistance. Moving on......

Frank