Clear ARP cache on MX's in an HA pair

[John_Sullivan]

I'm being asked by a vendor to refresh our ARP cache.  Is it still the case that you have to reboot the MX to achieve this?  If you reboot the primary MX, will the ARP table simply transfer to the Secondary MX?  If so, do we need to physically remove power to both MX's at the same time?  

[alemabrahao · Accepted solution]

Yes, it is necessary to reboot both, but why do you need to clear the ARP table?

[John_Sullivan]

Just to be clear, reboot both at the same time, correct?

I don't believe we really do, in fact, need to, but we're being requested to do so by a third party technology vendor as a troubleshooting step.  To comply, with their wish, I wanted to know what was involved.  

[cmr]

@John_Sullivan, yes, both at the same time.

[alemabrahao]

Yes.

[PhilipDAth]

I greatly doubt the primary and spare MX would synchronise their ARP cache.  They do a VRRP exchange and synchronize DHCP over udp/3483, but that is about it.
https://documentation.meraki.com/MX/Deployment_Guides/MX_Warm_Spare_-_High_Availability_Pair#DHCP_Sy...