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Juniper router upgrade: Difference between revisions

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== Known issues ==
== Known issues ==


* Junos 21.4R2-Sx doesn't work with (at least) the MX204 (the FPC doesn't come online)
* Junos 21.4R2-Sx and later will not work with <code>system services ssh root-login deny</code> (the FPC won't come online after the upgrade)
** https://supportportal.juniper.net/s/article/Junos-21-4-or-later-Root-login-is-required-for-copying-the-FPC-image-from-the-Junos-VM-to-the-Linux-host-during-upgrade-of-VM-Host-based-platforms?language=en_US
* Junos 21.2R2-Sx have an incompatibility with older (at least 17.x) Junos, preventing VRRP adjacency to establish with a MD5 key
* Junos 21.2R2-Sx have an incompatibility with older (at least 17.x) Junos, preventing VRRP adjacency to establish with a MD5 key



Revision as of 15:11, 7 September 2022

Known issues

Preparation

  1. Download the proper image to apt1001:/srv/junos/

All the steps bellow should be done with:
cumin1001:~$ sudo cookbook sre.network.prepare-upgrade <image-filename>.tgz <router-fqdn>

  1. Make room for the image
    • request system storage cleanup
  2. Save rescue config (just in case)
    • request system configuration rescue save
  3. Copy image
  4. Check checksum
    • file checksum md5 /var/tmp/$filename.tgz
    • Compare with checksum on Juniper's website
  5. Validate new image against existing config
    • request vmhost software validate /var/tmp/$filename.tgz
    • On Junos >=18.4 (after the upgrade to 21+)

Upgrade

  1. Check if console port(s) is(/are) working
  2. Depool site (optional)
  3. Drain traffic away from router
    1. Apply GRACEFUL_SHUTDOWN - https://phabricator.wikimedia.org/T211728
    2. Disable the peers
      • deactivate protocols bgp group Transit4
      • deactivate protocols bgp group Transit6
      • deactivate protocols bgp group IX4
      • deactivate protocols bgp group IX6
      • Adjust OSPF metrics
      • If eqiad/codfw drain the pfw3 link by increasing the MED value on both sides
  4. Ensure router is not VRRP master
    • show vrrp summary
    • set groups vrrp interfaces <*> unit <*> family inet address <*> vrrp-group <*> priority 70    
    • set groups vrrp interfaces <*> unit <*> family inet6 address <*> vrrp-inet6-group <*> priority 70
  5. Downtime host in Icinga and Alert-manager
    • sudo cookbook sre.hosts.downtime -r 'router upgrade' -t XXX -H 2 --force 'cr3-ulsfo,cr3-ulsfo IPv6,cr3-ulsfo.mgmt'
    • This needs to match the Icinga "hosts", cr3-ulsfo will match in AlertManager as well.
  6. Double check site has been fully drained of traffic before proceeding:
  7. Disable BGP sessions to LVS/PyBal load-balancers
    • deactivate protocols bgp group PyBal

If Multi RE:

  1. Remove graceful-switchover
    • deactivate chassis redundancy graceful-switchover
    • request system configuration rescue save (to not have the above statement in the rescue config)
  2. Install image on backup RE
    • request vmhost software add /var/tmp/$filename.tgz re1
    • This needs no-validate when upgrading to 21+
  3. Reboot RE1
    • request vmhost reboot re1
  4. Once back up (show chassis routing-engine), perform RE switchover (impactful)
    • request chassis routing-engine master switch
  5. Once done, repeat previous 3 steps for re0
  6. Rollback "Remove graceful-switchover"

If single RE:

  1. Install image on RE
    • request vmhost software add /var/tmp/$filename.tgz
    • This needs no-validate when upgrading to 21+
  2. Reboot router
    • request vmhost reboot

Both single and dual RE:

  1. Check if router is healthy
    • show log messages | last
    • show system alarms
    • show ospf(3) interface
    • show bgp summary
    • All green in Icinga and LibreNMS

Cleanup

    • request system storage cleanup
  1. Remove Icinga and LibreNMS downtimes
  2. Rollback "Drain traffic away from router"
  3. Rollback VRRP change if any
  4. Save rescue config (just in case)
    • request system configuration rescue save
  5. On vmhost devices, save the disk snapshot to the backup partition
    • request vmhost snapshot for single RE devices
    • request vmhost snapshot routing-engine both for dual RE devices