Hi Razoe, @MacuserJimredirects us to a perfect Url depicting the HA functionality in Meraki. However allow me summarize this for you. Your understanding is correct. For HA to work properly VRRP heartbeat shall reach either side ideally via L2 / L3 Core. Also (expcerpt from the Url) *There should be no more than one additional hop between them, and they must be able to communicate on all VLANs. Your queries. 1. Does the WAN1 in Building A and WAN1 in Building be have to be of the same subnet (minimum a /29)? Can they be two /30 IP Addresses (meaning they’re not of the same WAN Subnet). We can have WAN Interfaces of MXes on the different sub nets. However ideally we shall have a vIP based configuration. I guess this may not be possible in your case as the MXes are placed in two different buildings. */30 When using this option, the current Active MX will use its distinct uplink IP or IPs when sending traffic out to the Internet. This option does not require additional public IPs for Internet-facing MXes, but also results in more disruptive failover because the source IP of outbound flows will change. */29: When using this option, both MXes will use a shared virtual IP (vIP) when sending traffic out to the Internet. This option requires an additional public IP per uplink but allows for seamless failover because the IP address the network is using to communicate with the Internet will be consistent. The vIP for each uplink must be in the same subnet as the IPs of the MXes themselves for that uplink, and the vIP must be different from both MX uplink IPs. 2. I’ve seen images/diagrams where the MX1 needs to be connected to MX2 as well as MX1 Needs to be connected directly to SW2, and MX2 needs to be connected directly to SW1. Is this all necessary? Or it’s just additional redundancy? MX1 shall not be directly connected be MX2. This is an old configuration which is not recommended any more as there were Dual Master Issue cropping up. I have also updated your diagram with few comments. Hope this help you.
... View more