Routing

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Ask questions and share experiences about ACX Series, CTP Series, MX Series, PTX Series, SSR Series, JRR Series, and all things routing, including portfolios and protocols.
  • 1.  OSPF equal cost path selection question

    Posted 03-13-2021 19:15
    I came across the following from <https://www.juniper.net/documentation/en_US/junos/topics/topic-map/ospf-traffic-control.html>
    When there are multiple equal-cost routes to the same destination in a routing table, an equal-cost multipath (ECMP) set is formed. If there is an ECMP set for the active route, the Junos OS software uses a hash algorithm to choose one of the next-hop addresses in the ECMP set to install in the forwarding table.

    Anyone can teach me which items Juniper uses to hash to select one of the path ?  Any documentation related to this ?

    thanks a lot in advance !!


  • 2.  RE: OSPF equal cost path selection question
    Best Answer

     
    Posted 03-13-2021 20:30
    Hi

    Below link should help with regards to Hashing algorithm used for ECMP

    https://www.juniper.net/documentation/en_US/junos/topics/concept/interfaces-hashing-lag-ecmp-understanding-10002-10008.html#

    Hope this helps


  • 3.  RE: OSPF equal cost path selection question

    Posted 03-13-2021 20:35
    thanks so much for information !!!


  • 4.  RE: OSPF equal cost path selection question

    Posted 03-20-2021 19:35
    Take into account that the exact hash depends on the platform you have installed.

    Elvin


  • 5.  RE: OSPF equal cost path selection question

    Posted 03-20-2021 19:37
    thanks a lot !!