Hello,

Telco often provide and maintain an ONT to terminate their fiber Internet access services.
This ONT has a single fiber uplink port and a single Gigabit downlink port.

In my quest for higher resilience, I can subscribe to a second Internet access and install two routers
but if a router ever fails, one Internet access is lost.

How can I work around this and connect each ONT to both routers (of course, at most only one connection
is active at any given point in time) ?
I there some hardware that provides one Ethernet continuity when powered off and provides another Ethernet path when powered-on (*) ?
Shall I simply plus a Y-cable (one end in ONT, one end on each router) and "disable" the Ethernet port on the router ?

Best regards

(*) Years ago, BeroNet sold Fail Over Switches that could do that for Ethernet or TDM links

I think that the RB1100 (any version) has 2 ports with bypass, meaning that you can connect the ONT to the Eth11 and other router on Eth12.
You should put your dhcp client, ppeoe client or whatever yo use to acquire IP from the telco on both routers. While the RB1100 is on, the IP is acquired by the RB1100, but if it goes down automatically should be on the other router.

I take the opportunity to ask: Is there any other RB with this bypass feature?

I think that the RB1100 (any version) has 2 ports with bypass, meaning that you can connect the ONT to the Eth11 and other router on Eth12.
You should put your dhcp client, ppeoe client or whatever yo use to acquire IP from the telco on both routers. While the RB1100 is on, the IP is acquired by the RB1100, but if it goes down automatically should be on the other router.

I take the opportunity to ask: Is there any other RB with this bypass feature?

Thank you very much for mentioning this Bypass Feature: it is exactly what I was after.
I would also be curious to know if other Mikrotik devices support such feature.

For me, a dedicated Ethernet Bypass switch would make a lot of sense within Mikrotik portfolio as alternatives seem quite expensive and Mikrotik masters involved technologies (PoE, bypass, ...).

@olivier2831: there is nice summary about the bypass function with pictures: viewtopic.php?t=106092
It even mentions how the user applied bypass, to achieve WAN redundancy - I assume that is very similar to your case.

Only single thing worth mentioning myself - if you get two ONT from the same provider, those fiber uplinks will most likely run along each other and if there is any issue on the line, both may be affected at the same time. They may be even connected to the same optical transceiver on the other end.

The issue is not ISP availability its failure of the router unit as I read it.
So he wants the port from the ISP on the router, if there is a router failure to simply be a connection to another port on the router that leads to the second router.
The second router would have to be setup to accept this second WAN input and do some kind of load balancing.

Not sure if its a combo of vrrp with bypass or not.
Cant wrap my head around on how to tell the second router to use a connection that magically becomes alive???

The issue is not ISP availability its failure of the router unit as I read it.

Yes, you correctly read my issue: it's about router failure.
I can quite difficult to rack and configure one such router though they are not so expensive.
Having two routers backing each other would give me enough time to prepare and ship a replacement box.