Self assigned IP address on ethernet cable with plusnet hub one on Mac

[#1]

Think may have posted this on the wrong board, so trying again:

I have an iMac running OS Catalina, although the same issue was there before the recent OS upgrade

I have a new plusnet hub one router, with an ethernet directly to the iMac

In network settings, the wifi works fine, but the ethernet has the following message and won't connect:

"Ethernet has a self-assigned IP address and will not be able to connect to the internet."

I've tried up working through the network settings options: made sure it is "configure IPv4", using DHCP, renewed DHCP lease, tried setting up a new location (default one is automatic) and renewing DHCP lease on new location - no effect.

I'm coming to the conclusion it is a router issue. Any ideas?

Many thanks, Jasper

[#2]

Think may have posted this on the wrong board, so trying again:

I have an iMac running OS Catalina, although the same issue was there before the recent OS upgrade

I have a new plusnet hub one router, with an ethernet directly to the iMac

In network settings, the wifi works fine, but the ethernet has the following message and won't connect:

"Ethernet has a self-assigned IP address and will not be able to connect to the internet."

I've tried up working through the network settings options: made sure it is "configure IPv4", using DHCP, renewed DHCP lease, tried setting up a new location (default one is automatic) and renewing DHCP lease on new location - no effect.

I'm coming to the conclusion it is a router issue. Any ideas?

Many thanks, Jasper

[#3 · Accepted solution]

Well Jasper,

The issue (as you have correctly identified) is a failure of DHCP on the cabled connection.

Why I can't explain.

As a workaround, you could assign a static IP address (say 192.168.1.60), Subnet 255.255.255.0 and gateway 192.168.1.254 on the iMac.

If you have another router that will work with Plusnet (say a BT home hub) you could also try that.

I would also try a different cable between the iMac and the router and a different hole on the router.

[#4]

"Self Assigned" address means that for some reason it can't see the router/DHCP server.

First thing is : Try another network cable and plug it directly into the router if possible.

Then you could try a "Fixed IP" address:

IP Address = 192.168.1.10
subnet mask = 255.255.255.0
Gateway = 192.168.1.254

See if the fixed Network address gives you internet access.

[#5]

Thank you Mark

I'm slightly embarrassed. Changing the cable sorted it out. Should have tried that first I guess.

Anyway, it's saved me more head scratching, so thank you very much!

Best wishes, Jasper

[#6]

Thank you Bill

I'm slightly embarrassed. Changing the cable sorted it out. Should have tried that first I guess.

Anyway, it's saved me more head scratching, so thank you very much!

Best wishes, Jasper

[#7]

Hello Jasper,

Don't feel bad, it's a hole I've fallen down before, looking for a complex fault when the problem is simple.

I consider it a "learning experience" !