MX Warm Spare Query

[iPhilT]

Dear All,

Im a newbie in the community & new to Meraki as well. 🙂

I had a question regarding MX Warmspare setup in Routed Mode.

My setup is as follows:

• WAN1 Connected to ISP on a /30 subnet for which i get IP from DHCP
• WAN2 is MPLS Link connected to a single router
• LAN Connected to MS Switches

Can i configure Warm-Spare in this setup using the "Use MX uplink IPs" So that the configured IPs on MX1 just fails over to the spare MX2. Note that WAN1 has only 1 IP available.

[PhilipDAth]

No.

Each MX needs to have a unique address, and must be able to talk to the Internet.  You could get a second /30 circuit from the ISP and plug that in.  This will protect outbound web browsing and AutoVPN but wont protect inbound NAT.

You will want WAN2 on both MX units to connect to the same MPLS router.  You may need to use your switch to do this by creating a VLAN with 3 access ports in it, and putting the two WAN2 ports in it and the MPLS router.

[iPhilT]

Dear Philip,

Thanks for your reply.

I can do what you suggested for WAN2 MPLS - which means i need to use Virtual IP correct?

The LAN IP is routable to the internet. Will that help? if I use Virtual IP on the LAN IP as well?

Also what does "Use MX uplink IPs" mean? in what scenario do we use this?

Thanks.

[PhilipDAth]

>I can do what you suggested for WAN2 MPLS - which means i need to use Virtual IP correct?

You don't have to use Virtual IP.  If you use Virtual IP then all communications will go out NATed from that IP instead of the IP address configured on the MX WAN interface.

>The LAN IP is routable to the internet. Will that help? if I use Virtual IP on the LAN IP as well?

No.  The WAN interfaces must have Internet access.

>Also what does "Use MX uplink IPs" mean? in what scenario do we use this?

That means it uses the IP addresses configured on the interfaces when talking to the outside world.

[iPhilT]

Thanks Phil.