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Networking problem: 169.254.xxx.xxx IP address

Posted: Thu Jul 08, 2021 10:28 pm
by willi
Hi all, thanks for reading my question

I'm having a problem with connecting my MiSTer to the internet after installing it into a new case. The function worked fine previously. I'm wondering if I damaged the network adapter or if the installation timing is coincidental.

My MiSTer is connected directly to my router by LAN. I'm having a problem with the DHCP though and the MiSTer will only acquire a 169 ip address. The MiSTer's mac address is also not registering on my router's client list.

What I've tried:
- Restarting the modem and the mister
- Changing the ethernet cable, validating that it's successfully connecting other devices
- Assigning a fixed IP to the MiSTer's MAC address through my router. I'm using the default MAC address 02:03:04:05:06:07
- Manually connecting to the network through the MiSTer with connmanctl using the example in the wiki. This way I can manually assign an IP to the MiSTer but it's not connecting to the internet and still not appearing in my router's client list.

Is it possible this is hardware failure or am I making a mistake? Thanks for your suggestions.

- willi

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Thu Jul 08, 2021 11:54 pm
by FritoZipper
I had a very similar experience! I tried a fresh sd card image, an older one and even a 2nd de-10 nano with fresh install and still won't connect to LAN via router anymore. My spouse who's worked in IT for 20years tried to get it working and failed. I think the router is blocking that port or my ISP is blocking it. My only solution was to use my phones wifi Hotspot :(

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Fri Jul 09, 2021 2:55 am
by retro
Is the green LED on the DE-10 Nano's Ethernot port lit? If yes, then it shouldn't be a hardware problem.

Some routers may have problems with the default MAC address. You can force a change of the MAC address by going to Scripts > mac_address_change

Once the MiSTer reboots you should have a new MAC address. Revert back to DHCP and see if your router is able to assign an IP address to it.

FritoZipper is also right that some ISPs may reserve at least one (or even two if you have IPTV service from your ISP) Ethernet ports on the router.

Try using a cheap unmanaged switch to expand the number of Ethernet ports available to you.

I hope the steps above were useful.

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Fri Jul 09, 2021 4:13 am
by willi
Thanks for your suggestions, here's what I've tried:
retro wrote: Fri Jul 09, 2021 2:55 am Is the green LED on the DE-10 Nano's Ethernot port lit? If yes, then it shouldn't be a hardware problem.
The left green light is lit but not the right. I can't remember if both lights are supposed to give feedback on this port.
retro wrote: Fri Jul 09, 2021 2:55 am Some routers may have problems with the default MAC address. You can force a change of the MAC address by going to Scripts > mac_address_change

Once the MiSTer reboots you should have a new MAC address. Revert back to DHCP and see if your router is able to assign an IP address to it.
I ran this script and restarted my router/modem and the MiSTer. It did successfully update the MiSTer's MAC address but it's still not resolving a proper IP through DHCP and my router is still not seeing the MiSTer on its client list. I'll try a static IP config again this way but not feeling optimistic.
retro wrote: Fri Jul 09, 2021 2:55 am FritoZipper is also right that some ISPs may reserve at least one (or even two if you have IPTV service from your ISP) Ethernet ports on the router.
I did try changing the router ethernet port that I'm connected to, and confirmed the port is connecting other devices through DHCP.
FritoZipper wrote: Thu Jul 08, 2021 11:54 pm I had a very similar experience! I tried a fresh sd card image, an older one and even a 2nd de-10 nano with fresh install and still won't connect to LAN via router anymore. My spouse who's worked in IT for 20years tried to get it working and failed. I think the router is blocking that port or my ISP is blocking it. My only solution was to use my phones wifi Hotspot :(
That's interesting that you've run into the same problem but also a little discouraging that your expert spouse didn't find a solution :( . To clarify, even with a wireless adapter you still were not able to resolve DHCP through your router? And you had to connect wirelessly to your phone instead?

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Fri Jul 09, 2021 7:18 pm
by willi
I tried a fresh disk image today and that did not resolve the problem. FritoZipper if you could provide any more specific details about exactly how you encountered a similar problem I'd appreciate it, maybe there's an answer in the overlap between our experiences. I can't seem to make any sense of how this could be a hardware problem but I can't think of what else could be responsible as it was communicating with the router before I changed the case, but your account of switching out the board and having the same problem is really strange.

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Fri Jul 09, 2021 8:45 pm
by Bas
I'd be really interested in a packet capture on the line between your MiSTer and the router. The DHCP handshake isn't particularly complex but to debug it you need to see where it fails. Some routers can do captures on their LAN ports. Not sure if MiSTer has tcpdump on board, but that would enable a capture from the MiSTer side of things.

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Fri Jul 09, 2021 10:10 pm
by willi
Bas wrote: Fri Jul 09, 2021 8:45 pm I'd be really interested in a packet capture on the line between your MiSTer and the router. The DHCP handshake isn't particularly complex but to debug it you need to see where it fails. Some routers can do captures on their LAN ports. Not sure if MiSTer has tcpdump on board, but that would enable a capture from the MiSTer side of things.
I've poked around and I don't think I can capture packets from LAN ports on my router. Is there any way to install command line tools to the MiSTer without connecting it to the internet?

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Fri Jul 09, 2021 11:50 pm
by FritoZipper
I tested mine again and it's working now I changed nothing. I'm so confused 😕

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Sat Jul 10, 2021 12:11 am
by throAU
Try change the cable if you haven’t already.

I’ve been a network guy since the 90s and assumed a cable was still good too many times and gone down all sorts of diagnostic rabbit holes only to find the cable is bad.

You may well have damaged the port but definitely check cable first.

169 address means the device didn’t contact a dhcp server. Which means either the Nic (or switch/router port) or cable are bad or the dhcp server isn’t working / responding to it. If it was working before and all you changed was your case I’d be looking at the physical side of things. Cable or port (wall socket end as well if you have structured cabling. You could also have somehow dislodged something there).

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Sat Jul 10, 2021 6:11 pm
by willi
throAU wrote: Sat Jul 10, 2021 12:11 am 169 address means the device didn’t contact a dhcp server. Which means either the Nic (or switch/router port) or cable are bad or the dhcp server isn’t working / responding to it. If it was working before and all you changed was your case I’d be looking at the physical side of things. Cable or port (wall socket end as well if you have structured cabling. You could also have somehow dislodged something there).
Yeah, I've tried changing the cable but I am leaning towards some kind of damage to the port. I'm going to try connecting it to a different network and connecting it by WiFi in the coming week.
FritoZipper wrote: Fri Jul 09, 2021 11:50 pm I tested mine again and it's working now I changed nothing. I'm so confused 😕
Hard to complain about that. Hopefully mine does the same!

Thanks all for your suggestions I'll post an update after I've tried troubleshooting the port.

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Mon Jul 12, 2021 12:38 pm
by retro
willi wrote: Fri Jul 09, 2021 4:13 am The left green light is lit but not the right. I can't remember if both lights are supposed to give feedback on this port.
Just having the left light lit is fine... the right orange light is only when there's activity.

Another thing to do is ensure there are no other devices connected to your router. Turn everything off, including the router's WiFi radio temporarily.

Connect the MiSTer and a PC via Ethernet to the router, the latter to login to the router's admin page.

If there's still no activity, try looking for an Ethernet crossover cable and connect the MiSTer directly to your PC to see if they're able to communicate with each other.

If yes, then you can establish an SSH connection to MiSTer with Putty, and set a static IP address to eth0.

Once that's done, reconnect the MiSTer to the router and see what happens.

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Mon Jul 12, 2021 1:34 pm
by throAU
Be aware that link light doesn’t always mean all good.

It’s just a carrier detect light. If your send pins are buggered on the cable or port the connection may well have a link light but not show anything.

I’m not sure if tcpdump is installed in the mister or not but if so you can maybe use it to see if the NIC is “seeing” any Ethernet frames from the network inbound

Re: Networking problem: 169.254.xxx.xxx IP address

Posted: Sat Jul 17, 2021 11:15 pm
by willi
This problem was solved by connecting via wifi, which confirms to me that there must have been some kind of damage to the ethernet port.

Thanks all for your suggestions.