topic Re: Using My Own Router, Correct Way to Setup? in Broadband

Using My Own Router, Correct Way to Setup?

noname123456 — Sat, 17 Oct 2026 17:16:36 GMT

Hi,

I have FTTP using a BT ONT and I have being using my own router Flint 2 (GL-MT6000) for the last 6+ months and in that time I have have two instances where the network just drops (no errors in the logs that I can see) and it will remain like this until I power-cycle my router.

I have set this up using DHCP 61 as per this post but I have also read that you shouldn't need to use this method here.

Can someone please tell me what is the current correct way to setup your own router when using FTTP using a BT ONT and have others experienced similar issue with their network dropping using their own router or same as mine?

Thanks

Re: Using My Own Router, Correct Way to Setup?

noname123456 — Sun, 18 Oct 2026 07:06:59 GMT

Turns out this problem is quite common when people want to use their own routers with Sky FTTP as they use either CG-NAT or MAP-T systems.

If there's no work-around, then we will be leaving to either BT or Plusnet who don't use any of these daft systems.

Re: Using My Own Router, Correct Way to Setup?

Chrisee — Sun, 18 Oct 2026 07:44:48 GMT

@noname123456 no idea where you got that information but it is not correct. Sky can only use MAP-T on routers that advertise support for DHCPv6 Option 95 which their white Sky Max and Sky Gigafast+ hubs do but third party routers normally dont.

It is therefore highly unlikely that is the cause of the issue but its worth checking the set up on the router. It sounds like occasionally the router is missing the hourly IP lease renewal.

Re: Using My Own Router, Correct Way to Setup?

GD1 — Sun, 18 Oct 2026 08:11:26 GMT

@noname123456 Using a Dryatek 3910 with DHCP Option 60/621 on FTTP the uptime is 24 days (did a firmware update) witoiut any drops, so I suspect as @Chrisee states is a hourly IP release issue.

Re: Using My Own Router, Correct Way to Setup?

noname123456 — Sun, 18 Oct 2026 08:41:54 GMT

Thanks for your reply.

I have followed this advice to set up my router on DHCP Option 61 (Client ID)

Like I said, it only drops when Sky change my public facing IP which is roughly every 56 days.

I have looked all over the web and have gathered lots of info for this issue and others have the same issue, as found here:

It does seem to be linked to how Sky uses the CG-NAT & MAP-T systems where other ISP don't and they don't have this problem.

This is exactly what I see on my routers 'Internet page' when I lose the connection after the 56 day period:

Sky's use of MAP-T (Mapping of Address and Port using Translation) on their FTTP network. When Sky rotates your public-facing IPv4 address, it shifts you into a shared 100.x.x.x (CGNAT-style) range. The GL.iNet Flint 2 (GL-MT6000) fails to handle the routing table refresh under MAP-T automatically, causing the internet handshake to break completely until the interface or router is manually restarted.

If you could suggest another way to get this working I'm happy to try it.

Re: Using My Own Router, Correct Way to Setup?

Chrisee — Sun, 18 Oct 2026 10:49:52 GMT

@noname123456 I repeat it can't be MAP-T unless your router is advertising support for DHCPv6 Option 95.

Re: Using My Own Router, Correct Way to Setup?

TimmyBGood — Sun, 18 Oct 2026 11:51:29 GMT

@noname123456 wrote:

If you could suggest another way to get this working I'm happy to try it.

If the issue is an unfortunate interaction between GL.iNet hardware (and/or OpenWRT) and Sky network implementation then it's up to them to solve it, although given GL.iNet is an extremely minor vendor on the domestic broadband market this may just be unrealistic.