Junos OS

Hi everybody.

Please consider the following from my book:

The last option you may use with the commit command is synchronize. When you have a
router with two Routing Engines installed, you can have the router apply the candidate configuration
to both Routing Engines.
[edit]
user@router# commit synchronize
re0: configuration check succeeds
re1: configuration check succeeds
re0: commit complete
re1: commit complete
[edit]
user@Shiraz#
This option is helpful in the event of a Routing Engine failure; the backup Routing Engine
now has the latest operational parameters in the network.

##################

Let say we have a Juniper router with two RE; RE1, RE2

RE1 is active . we configure OSPF on RE1, we commit the change without " synchronize". After a few days, RE1 crashes,

Will the new RE2 have OSPF config ? If yes, why we have not used "commit synchronize" 

To put it another way:

Does using " only commit"  not allow RE2 to get synch with RE1's config? 

Do we have to use " commit synch " to force R2 synch with RE1's config?

Thanks and much apprecaited!!

Hi,

Does using " only commit"  not allow RE2 to get synch with RE1's config? 

No. Commit will not replicate the changes to the backup RE.

Do we have to use " commit synch " to force R2 synch with RE1's config?

Yes.

Regards,

Rahul

Please mark my solution as accepted if it helped.

Thanks Rahul.

Hi,

It is also possible to embed "commit synchronize" in system settings so that just issuing a commit will automatically synchorize the config accross REs. Recommended for dual-REs.

https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/routing-engines-configuration-synchronizing.html

Cheers,

Ashvin