Meraki Z3 freaks out when the WAN IP address changes

[PhilipA]

I have two ISPs at home, each with each own router, joined together by a load balancing router. This provides me with seamless failover; if one of the ISPs fails (i.e. if my load balancing router can not ping 8.8.8.8 from that WAN port) then all of the traffic is redirected through the other ISP. Naturally, the switch from one ISP to the other causes my external IP address to change.

Every time such a switch happens, my Meraki Z3 freaks out, drops its VPN tunnel, and refuses to reconnect. The light stays solid white, but I can no longer ping other workstations in the company network (or access the internet at all). I suspect that this happens because the Z3 freaks out when it sees that its external IP address has suddenly changed.

The only thing I can do at this point is power-cycle the Z3, sometimes it takes multiple tries, and then reset my network adapter. Is there something I could do to prevent this from happening or to help the Z3 recover in a more deterministic way?

[PhilipDAth]

The Z3 (and the MXs) don't work well behind load balancers.  More than likely the existing VPN registration still has the old IP address, because it can't detect that there has been a public IP address change.

Unplugging the WAN port and plugging it back in again is likely to resolve it.  Power cycling the Z3 should definitely resolve it.

[PhilipA]

Thanks Philip! This is usually resolved by power-cycling the Z3 once. However, sometimes I power-cycle the Z3, wait until the light turns white, reset the networking adapter, but am still unable to connect anywhere. So I repeat the process again and again until it works. But last time it took 6 tries, which is very time consuming and non-deterministic! Could you think of a possible explanation for this behaviour?

[PhilipDAth]

You should only need to reset the Z3 and nothing else.

Here is a plan to try:

1. Reset Z3

2. Make and consume a coffee.

I bet by the time step 2 completes it will be working.

[Inderdeep]

@PhilipA : As @PhilipDAth said, the main point is point no 2 : Make and consume a coffee 🙂 

[PhilipA]

When you say "Reset Z3" do you mean to simply power-cycle it or do you actually mean using a paperclip to reset the device to factory settings? I am asking because simple power-cycling often times does not work!

[PhilipDAth]

Power cycle.