multi wan with same upstream gateway IP supported?

[sjjh]

Following set up: two PPPoE gateways (two separate contracts) from the same ISP: one smaller uplink for VoIP and one bigger uplink for all the other traffic (mainly surfing the web). Firewall/NAT rules to choose the correct gateway. IP addresses of the gateway are assigned by DHCP from the ISP. The ISP differentiates them by the PPPoE credentials and assigns us the respective WAN IP address. As both gateways come from the same ISP and are only two different sized contracts, both gateways receive the same upstream gateway IP address by the ISP.

As we do have a mixture of different connection problems and I cannot really find the solution, I was researching on the net and stumbled upon a github issue. If I understand the comments by fichtner correct, this set up might not be supported at all.

Is my understanding correct, that it is not supported to have two gateways with public IP addresses A and B which both have the same gateway with IP address C?
I'm asking, because I do not see any error message in the Web GUI and I would have assumed that I do get an error message in the Web GUI if it is not supported. If someone can confirm my understanding, I'm happy to open a ticket.
Simon

[franco]

While multipath is in the kernel since FreeBSD 13 we disable it by default since it messes with the routing in undesired ways. And even with this I'm not sure if this works now.


Cheers,
Franco

[sjjh]

Thanks for your confirmation. I opened a ticket.
Simon

[franco]

Hi Simon,

Please don't mind me nagging. I'm trying to understand where and what we should present. It's not that easy for runtime data.


Cheers.
Franco

[sjjh]

Don't worry. I'm interested in finding a good/correct solution myself.
I only fear my knowledge might be too limited to help. In case a view at our installation would help, just let me know via PM and we can figure that out.
Simon

[franco]

The setup info in the GitHub issue is appreciated. I'm surprised this works better than expected. Might be another issue here.


Cheers,
Franco