Routing

Hi Guys,

I got an MX480 with dual RE. when the router restarted it picked the backup router and not the active one. Now we made some configuration changes to this routing engine and now i want to restore the master RE. My understandings are, when I plug in the new routing RE0, it should be a backup RE and should synchronize to the RE1, which is the master, and there is no Preemption in this, The RE0 will be master on the next reboot. Can some body please confirm it?

Thanks

IG

Hello,

On M/T/MX series with dual REs and default settings the Routing Engine in slot 0 is preferred master.

JUNOS and config sync between RE is not a default behaviour, you have to manually ensure that JUNOS on both RE is compatible with HW/linecards in the box (JUNOS versions on both REs may be different if you don't use GRES) and to sync config, use "commit sync".

Once both REs on the the box with dual REs are simultaneously rebooted, then RE0 becomes the master after coming up.

You don't have to simultaneously reboot both REs to achieve that, just do "request chassis routing-engine master switch [no-confirm]" to switch mastership.

HTH

Regards

Alex

Hi Alex,

I just wanted to confirm, that if the failed master comes up after 2,3 months, will it preempt the master which is RE1 at the moment. According to document it should not, but i have not done it practicaly before.

Thanks

IG

Hello,

The length of time does not matter. There is no preemption of working master RE in M/T/MX product line unlike in EX VC product line.

Backup RE0 could become master again if:

1/ "request chassis routing-engine master [switch|acquire]" is executed

2/ RE0 is up but RE1 goes down

3/ both REs are coming up simultaneously after complete power loss

4/ both REs were simultaneously rebooted

HTH

Rgds

Alex