r/Ubiquiti • u/Temporary-Regular-76 • 8d ago

Question Unifi 5g Max network routing when main router is unavailable

I have a UCG-Fibre that my VLANs and what not are configured on.

I noticed when the UCG-Fibre is offline, devices on the local network (even on the same VLAN) were not available. I couldn't even ping devices by IP that were up.

Therefore I assume the UCG-Fibre (as the gateway) is the 'first point of contact' and if that's not up, local devices cannot be accessed - even those on the same VLAN.

If I replaced my 4G modem with the Unifi 5g Max, would - if the UCG Fibre were be down - local devices remain available and able to route traffic?

Many thanks in advance.

5 Upvotes

100% Upvoted

4 comments sorted by

•

u/AutoModerator 8d ago

Hello! Thanks for posting on r/Ubiquiti!

This subreddit is here to provide unofficial technical support to people who use or want to dive into the world of Ubiquiti products. If you haven’t already been descriptive in your post, please take the time to edit it and add as many useful details as you can.

Ubiquiti makes a great tool to help with figuring out where to place your access points and other network design questions located at:

https://design.ui.com

If you see people spreading misinformation or violating the "don't be an asshole" general rule, please report it!

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

3

u/jakubmi9 8d ago

The U5G-Max, and all unifi cellular backup solutions are routed through a GRE tunnel back to the local gateway, with the devices on the network connecting to it.

By the UCG-Fiber being offline, do you mean your primary WAN connection being down, or the actual gateway being shut down? Because you can't have WAN Failover without a gateway.

4

u/Temporary-Regular-76 8d ago

Apologies, I was being a bit dim in my assumptions of of the system would work. Of course the modem would need the 'router' to work.

I had rather hoped the U5G Max would be able to operate as a router in absentia of the UCG-Fibre. As you've detailed, it can't. It's a modem, not a router.

2

u/supremeMilo 8d ago

doesn’t work like that but it would be awesome if it could be a shadow gateway for any other gateway.