Why Would Someone Move the ONT Output to the Wrong Port?

Forums › LAN (ethernet/Wifi/routers/Bluetooth) › Why Would Someone Move the ONT Output to the Wrong Port?

MikeAqua

8031 posts

Uber Geek
+1 received by user: 3820

#323979 11-Feb-2026 15:10

We just moved house. We had trouble getting the Fibre connection up and running. ISP of course immediately blamed our modem-router because it wasn't supplied by them. The ISP eventually accepted that the modem-router configuration was just fine (which I already knew ...). However, it turned out the ONT out cable was connected to Lan 2 port on the ONT (Chorus Model 400). Plugging it into Lan 1 immediately resolved the issue.

This has me wondering why anyone would plug the cable into the Lan2 port in the first place. Do different ISP's use different LAN ports or something?

Mike

Behodar

11101 posts

Uber Geek
+1 received by user: 6092

Trusted

Lifetime subscriber

#3460661 11-Feb-2026 15:19

When switching ISPs it's relatively common to activate the new ISP on port 2 a day or two before terminating the connection on port 1. This allows you to switch with only a couple of seconds' interruption.

muppet

2644 posts

Uber Geek
+1 received by user: 1662

Trusted

#3460664 11-Feb-2026 15:22

I have two different services on my ONT at home (one is port 1, one is port 4)

xpd

Geek of Coastguard
14116 posts

Uber Geek
+1 received by user: 4579

Retired Mod

ID Verified

Trusted

Lifetime subscriber

#3460684 11-Feb-2026 16:08

No such thing as a wrong port :) Just depends on the activated port :)

XPD / Gavin

LinkTree

ascroft

437 posts

Ultimate Geek
+1 received by user: 177

#3460739 11-Feb-2026 16:44

Port No is normally covered in Chorus provisioning comms now. You may not be in a Chorus location tho.

"Artificial Intelligence" - aka Machine Learning 2.0

boosacnoodle

1280 posts

Uber Geek
+1 received by user: 862

#3460790 11-Feb-2026 20:06

Covered in Enable comms, too.

everettpsycho

668 posts

Ultimate Geek
+1 received by user: 270

#3460792 11-Feb-2026 20:22

It used to be the would provision sequentially on the minimum available port. So new services are port 1, if you have a service it goes to 2 and so on so forth. There was probably a second connection when cutting over previously th as t out it on port 2 and the new service has just been stuck back on 1 as the obvious choice.

Live int comms usually say what port to use but most people ignore it then spend ages with customer service trying to figure out what is going on.

Dell

Shop now for Dell laptops and other devices (affiliate link).

nitro

761 posts

Ultimate Geek
+1 received by user: 338

#3460864 12-Feb-2026 09:27

MikeAqua:

However, it turned out the ONT out cable was connected to Lan 2 port on the ONT (Chorus Model 400). Plugging it into Lan 1 immediately resolved the issue.

This has me wondering why anyone would plug the cable into the Lan2 port in the first place. Do different ISP's use different LAN ports or something?

who plugged it into Port 2? seeing as you provided your own router...