MWAN3 has long had an issue with IPSets causing WAN failover to not function as expected. There are some hacky workarounds (such as in this thread: 23.05 dnsmasq, ipsets and mwan3 incompatibility? - #28 by jamesmacwhite) which can get it working, but for the most part, it's not a great experience.
Before I embark on this rabbit hole myself, has anyone managed to test out OpenWrt 24.10 to see if MWAN3 is working as expected yet? Whilst I'd rather not use the various workarounds I've had to employ in the past, just getting it working eventually would be nice. I deal with regular dropouts so this is an important one for me to have working. Thanks in advance.
The problem is not OpenWrt.
The problem is that mwan3 depends on legacy iptables, no longer supported by default on OpenWrt.
Mwan3 needs to be migrated/refactored to use nftables, otherwise it should be regarded as an "End of Life" legacy package, unfortunately.
I would even say, it should not be an add-on package. Having a check whether a network link really works and adjusting the routing based on this should be part of the out-of-the-box experience.
Here in the Philippines, PLDT started deploying combined fiber/mobile routers with the fail-over logic built in. If OpenWrt loses in terms of correctly implemented and usable features to the very bare-bones default ISP router, well, it loses users. And that's a real risk here.
Agreed, the package is overdue for an overhaul - there was some talk of this but not sure if much progress has been made. I am actually a bit surprised that it isn't something that is integrated as a core part of OpenWrt, failover is a big reason I have deployed OpenWrt in the past and it would be a shame to have to look into other router OSes just for this one feature.
While mwan3 might have issues with ipsets, I am using it to balance the load among x2 4G/5G connections with success. IMHO it is key to have a load balance/failover solution like mwan3