Multi-Wan IPv4 setup

[rfanch3r]

I saw someone posting this on IRC so I followed it but its not working the way I expected it to. https://www.thomas-krenn.com/de/wiki/OPNsense_Multi_WAN#2_WAN_Verbindungen_ohne_IPv6, I just translated this to English.

My expectation was that if the main gateway was down to use the alt, then when the main one came back it would switch back however, something happened today and now all traffic is going through the alt and I don't see it switching back. Not sure if I need to do anything manually or not.



Anyone have another reference I can use that you found successful?

[vico1959]

Okay so I have just recently gotten this setup on mine and it does not seem to be intuitive or work correctly as one would think. I had to play around with a lot of things to get it working but finally it seems to be so let me mention all of the things I have tweaked as a list of questions:

1. Have you setup the gateway group?
2. Have you adjusted the priority (1 main and 2 alt) and weight(keep weight at 1 for both) settings in the single gateway options and the tier settings (1 main and 2 alt) in the group?
3. Have you checked upstream gateway on both so that they can be used as a default gateway?
4. Have you checked far gateway for any gateways not in the same IP subnet.
5. Have you configured the DNS servers to use gateways in the general settings?
6. Have you configured the monitor IPs for each single gateway, (or at least the main, more on this later) you can use any external DNS server for this?
7. Have you checked the "Allow default gateway switching" box in General settings?

I chose member down as the trigger for switching but the main gateway needs higher priority and tier. I also had to check allow DNS server list to be overridden for the DNS to work reliably over DHCP connection on the alt. You can exclude the main WAN from this too. I also disabled the gateway monitoring on the alt so it would consider it as always being up since it is a 4G cell connection and I didn't want any intermittent connection issues to cause the system to think it was down when it is in use.

I hope this helps in some way.

[rfanch3r]

@vico1959 Please check back in a couple of days. I have to wait till my house hold is hardly using the inet before I am able to verify and or make changes. I did go though all of the steps as outlined in this doc: https://docs.opnsense.org/manual/how-tos/multiwan.html

I did find I have some minor errors that may be the cause of my issue.

Did you follow any how-to's? Or did you just wing it?

[rfanch3r]

@vico1959 I do have 1 question before answering all of the others:

Have you adjusted the priority (1 main and 2 alt) and weight(keep weight at 1 for both) settings in the single gateway options and the tier settings (1 main and 2 alt) in the group?

In my group I have the following:
WAN1 Tier 2
WAN2 Tier 1

Priority for the single's
WAN1 Priority 255
WAN2 Priority 250

Weight
WAN1 - Set to 1
WAN2 - Set to 1

However the verbiage in the docs are to set the weight to 1 on the lower link and set the weight to 2 on the higher link.

I have trigger level set to Packet Loss, High Latency. I did not choose the Member Down option because the link in the past, never goes down just stops routing due to upstream issues.

My question is, whats the advantage of setting the weight to 1 for both? And will this achieve what I am looking for which is to have my larger bw link be the primary (WAN2)

[vico1959]

At first I followed instructions in the documentation here on the OPNsense site but then I ran into the exact same problem you describe in your op so that is when I started playing around with things. I posted here but didn't get any good answers in time so I kept playing around with settings to try and figure out exactly what each did.

From what I could gather, I understood weight to be how much priority each connection would have in more of a load balancing setup but I just kept them at 1 because I figured in a failover situation they should both have the same weight and other criteria should decide on which is in use. Tiers and priority seem almost like they would perform the same functions so it is a bit confusing there. I'm not sure if Tier in a group overrides priority or not or if they have some other unknown purpose.

Packet loss in your case sounds like it might be the best choice. I tried packet loss but in the end I had gone back to member down for my purposes. I'm actually not sure if it had any bearing on me finally getting it working or not because I was changing several options at a time sometimes and never went back to flush out the exact changes that made it work.

I do believe that what made it finally start switching back to the main default WAN properly is the "Allow default gateway switching" box being checked but again I haven't done any verifying of that.

[goseph]

See here about this issue seems to be caused by using DHCP (PPPOE not clear yet):
https://github.com/opnsense/core/issues/4160