[SOLVED] Ethernet cable not always detected ?

[JasonRSmit]

Long time browser of the forum, first time asker.

I have a weird issue that has cropped up and would like to know the best approach at resolving it. I have a custom single board computer(running linux) that does some measurements. It has a built in ethernet port that has been in use before for internet. The issue I am having is that I needed to change the network layout a little which requires a new router. The port does not recognise that a cable has been connected when I connect it to the new router. It does recognise the cable when connected to another computer(2 others tested). This issue is now occurring for the old router as well. Is there any reason that the port can detect PCs but not routers and switches? I know this is a very weird arbitrary issue but any assistance would be appreciated.

 

[mrmike16]

Your PC can see other PCs, but can't access the internet? And the others can't either? If so, check the modem and the connection between the modem and the router.

 

[CountMike]

Long time browser of the forum, first time asker.

I have a weird issue that has cropped up and would like to know the best approach at resolving it. I have a custom single board computer(running linux) that does some measurements. It has a built in ethernet port that has been in use before for internet. The issue I am having is that I needed to change the network layout a little which requires a new router. The port does not recognise that a cable has been connected when I connect it to the new router. It does recognise the cable when connected to another computer(2 others tested). This issue is now occurring for the old router as well. Is there any reason that the port can detect PCs but not routers and switches? I know this is a very weird arbitrary issue but any assistance would be appreciated.

Probably just wrong IPs for those, there's no physical cause.

 

[JasonRSmit]

That's the strange part it physically does not recognise and communicate when an Ethernet cable is connected. Routers are not a problem as I have other devices connected with no problems. I can see there is no attempt at a connection by the physical leds on the port. Is there perhaps a way in which I can force the software to attempt a connection?

I can connect to internet if I share it from the PC's as a response to mrMike
Edited: Spelling

 

[mrmike16]

That's the strange part it physically does not recognise and communicate when an Ethernet cable is connected. Routers are not a problem as I have other devices connected with no problems. I can see there is no attempt at a connection by the physical leds on the port. Is there perhaps a way in which I can force the software to attempt a connection?

I can connect to internet if I share it from the PC's as a response to mrMike
Edited: Spelling

It wouldn't make much sense here, because of the fact that this happened only when you switched routers, try reinstalling the network adapter on the affected PCs.

If it is the IP address, then you can use the ipconfig /release and ipconfig /renew commands in Command Prompt as Administrator.

It's interesting that your ethernet LEDs do not light up, but the connection to the router is still there to reach other PCs. So it does have a connection, it just isn't saying so, and it can't get to the Internet, so something is off.

 

[JasonRSmit]

It wouldn't make much sense here, because of the fact that this happened only when you switched routers, try reinstalling the network adapter on the affected PCs.

If it is the IP address, then you can use the ipconfig /release and ipconfig /renew commands in Command Prompt as Administrator.

It's interesting that your ethernet LEDs do not light up, but the connection to the router is still there to reach other PCs. So it does have a connection, it just isn't saying so, and it can't get to the Internet, so something is off.

I get lights when connecting to the PCs but not when connecting to the router. I am going on site again tomorrow, and I am going to give the port a good clean. I have a feeling it might be some dirt in the connector. I'll try a module reload on the ethernet for good measure.

 

[ex_bubblehead]

Replace the cable. It's not unusual for a marginal cable to work in one setup and not another. Cleaning ports is rarely (if ever) the fix and you risk bending the fingers inside the port, which will quickly render it unusable.

 

[JasonRSmit]

Replace the cable. It's not unusual for a marginal cable to work in one setup and not another. Cleaning ports is rarely (if ever) the fix and you risk bending the fingers inside the port, which will quickly render it unusable.

Thanks a lot ex_bubblehead I will definitely use a brand new cable when there. Must admit I've never experienced something that has made me feel so helpless