MX Warm spare

[RichPekarsky]

This question is not service impacting per se, but it is one that I don't understand.  We have warm spares at all of our sites.  Almost all of them have the address that is input into the primary.  When I do an export of all of the org equipment, I get several MX warm spare devices that do not have the address populated.  Since there is not a way to input an address into the warm spare MX dashboard page, my question has two parts:

1. where does the MX warm spare devices generate or collect the address that is in the primary MX?

2. Why are some not showing this information and how to remediate the issue?

Thanks

Rich

[jdsilva]

Are you talking about the LAN address?

[RichPekarsky]

sorry no the physical address...here is a sample...

SN-0115-01	MX84	2275 Health Dr SW, Wyoming, MI 49519
SN-0115-02	MX84
SN-0116-01	MX84	5221 Cherry Ave Hudsonvill​e, MI 49426
SN-0116-02	MX84	5221 Cherry Ave Hudsonvill​e, MI 49426

[cmr]

Interestingly on the dashboard the passive applicable doesn't have an address either.  Perhaps the ones that show up have been the active appliance at some point and the ones that don't have not...?

[jdsilva]

The spareMX uses the same physical address as the primary.

When the spare is Passiveit does not send any frames on the LAN whatsoever. Once the spare becomes Master it then uses the MAC of the Primary. 

Here's some pcaps to illustrate:

Primary as Master, sending VRRP:

And the Spare, now as Master, sending VRRP:

The only way you can actually tell the difference it looking at the Priority value of the VRRP packets to know which device the it came from. I assure you though, these were sent from two different MX's that were in a Warm Spare. 

[cmr]

@jdsilva @RichPekarsky is referring to the street address, not the layer 1 address.  If you go to the standby MX in the dashboard there is no street address shown...  It should be where the question mark is:

 

[jdsilva]

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@cmr wrote:

@jdsilva @RichPekarsky is referring to the street address, not the layer 1 address.  

 

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Haha WOW I can be pretty dense sometimes! I'll go back to my hole now.