Junos OS

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  • 1.  Upgrading MX104

    Posted 08-11-2021 15:25
    Hello Junos Community,

    I am planning to upgrade Juniper MX104 router. I have read articles in juniper documentation that say there will be some down during RE switchover. 

    However, I want to understand how long the routing will remain down? Also, do interfaces also go down during switchover?

    Regards,
    Rahul

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    Rahul Nangare
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  • 2.  RE: Upgrading MX104

    Posted 08-11-2021 19:44
    If you configure you dual routing engines using both GRES and NSR you can perform the upgrade using ISSU and have no downtime during the upgrade.

    https://www.juniper.net/documentation/us/en/software/junos/high-availability/topics/example/issu-upgrading.html

    To upgrade each routing engine separately with manual switchover and card reboot downtime review these options.

    https://kb.juniper.net/InfoCenter/index?page=content&id=KB8911


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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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  • 3.  RE: Upgrading MX104

    Posted 08-12-2021 05:26
    Based on experience, if is a single Routing Enginer (RE), downtime is not beyond 17 minutes.

    Elvin


  • 4.  RE: Upgrading MX104

    Posted 08-12-2021 14:20
    Based on experience on MX104 / double RE:

    • normal update procedure (GRES / NSR disabled, no ISSU):
      • disable GRES/NSR
      • installation of update package on the backup RE (5 mn) – no downtime
      • 17 minutes to reboot/update the backup RE (no downtime) - actually when it reboots it immediately executes the install script and self-reboots again using now the new version
      • 5 minutes of downtime when you switchover to it (the forward-plane reboots and ports are down)
      • a few minutes for the routing to be operational (IGP/BGP), between 2 and many minutes depending of the number of BGP routes,
      • installation of update package on the new backup RE (5 mn) – no downtime
      • then 17 mn to reboot/update this RE
      • then you can re-enable GRES/NSR (and declare in the config the current master RE as master, and current backup as backup, in order to avoid «backup RE is active» alarm)
    • ISSU: you don't know when / how / how much you'll have downtime.


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    Olivier Benghozi
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