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  • 1.  BGP Flaping session - how to prevent of high load RE CPU

    Posted 11-19-2021 12:00

    Hello!

    We have one chassis MX960 with installed two old RE-2000-S and several BGP sessions on it (upstream and downstream)
    For our clients we advertise full view routing table with direct eBGP sessions

    Now we are faced with the problem of CPU overloading at the time of transferring routes prefixes to our clients after BGP session start flapping
    We fully understand that we need to swap that RE but today we are need to prevent impact of flapping BGP sessions to our CPU

    The dump mechanism protects only incoming routes, but what about the routes outgoing from us?

    How to set a penalty to export routes and prevent high CPU of BGP flapping session?

    Thanks in advance for any answers!



  • 2.  RE: BGP Flaping session - how to prevent of high load RE CPU

    Posted 11-19-2021 14:46
    Are you sure you need to slow down convergence?
    I also 5 Full view eBGP sessions and with several client which receives full view from me and about 8 non full view peers.
    In case of many bgp sessions flapping CPU also reach 100% load but no more than 5-7 minutes, but this is RE-1800.
    This doesn't leads to problems with service.
    Maybe you have some another problem.
    Nevertheless I think you should look at this
    https://www.juniper.net/documentation/en_US/junos/topics/topic-map/bgp-flap-damping.html
    Maybe this helps.


  • 3.  RE: BGP Flaping session - how to prevent of high load RE CPU

    Posted 11-20-2021 11:27
    Depending on what routes you are advertising and the nature of the flap adding an out delay wait time might help for the exports.

    https://www.juniper.net/documentation/us/en/software/junos/bgp/topics/ref/statement/out-delay-edit-protocols-bgp.html

    As you note the real answer is the upgrade off the memory limited re 2000.  But we all need to just bail water sometimes.

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    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
    http://puluka.com/home
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