DHCP Failure

[Mihai-Florin.Necula]

Hi there,
Could you please help me with an issue which is keeping my station offline?

The error message on my station is DHCP failure with the displayed IP 192.168.1.103 (mask 255.255.0.0)
I cannot access the station by imputing the static IP apearing on the screen

I have both the router assigning this IP to the station in permanent mode and also the station was configure to have this IP and mask but I cannot find a way to access the station.
Problems with DHCP started some time ago (this is why I configured the station to have a static IP) and everytime the DHCP failure error presented itself I could not access the station.

These were usually sorted out by shutting down the router and the station for some time... but nothing works this time around.

later update;
just performed an hard reset (pressing both buttons to return to original values) and enabled the router to assign any IP to the mac of the station but I still cannot access the station on the default 192.168.1.235 IP now showing on the screen

[Steph]

Hi,

Is the IP-Address of your computer in the same subnet?

[Mihai-Florin.Necula]

Hi,

Is the IP-Address of your computer in the same subnet?

Hi Steph,
On my home LAN the IP of my computer is 192.168.1.200 and now (after the hard reset) the station has 192.168.1.235 (mask 255.255.255.0) so they should be in the same subnet. Router is also on 192.168.1.1 (mask is 255.255.0.0). Both the light on the router and on the station show that the cable is connected and transmitting some kind of data but for some reason the I cannot even ping the station from both the router or computer.
This is not a new problem as it also appeared in the past (and with similar behaviour). It was usually sorted out by shutting down both router and station, but now this solution is not valid anymore. Even if my router works fine, I would be tempted to see it as an router issue but I do not know how to test this.

I also reset to factory defaults my router and the same thing happens. I cannot access the station.
The station notices when I unplug the wire or reset the router (Check network cable error) but once the cable is plugged in (or the router working) the same DHCP failure! message appears.
So the router does not see the station as trying to connect/the mac does not show in the router tables (even if the network lights on both router and station are blinking).

[Steph]

So the router, your pc and the station have different subnet masks? I'd set it to 255.255.255.0 on the DHCP-server on the router and check if all clients get get the same subnet mask.

[Mihai-Florin.Necula]

So the router, your pc and the station have different subnet masks? I'd set it to 255.255.255.0 on the DHCP-server on the router and check if all clients get get the same subnet mask.

ok, I reseted everything but still I cannot connect to the station/cannot ping the station.

Rounter
192.168.1.1 (mask 255.255.255.0)


PC (Automatic IP issued by DHCP)
192.168.1.100 (mask 255.255.255.0)



Station (shows on display)
192.168.1.235 (mask 255.255.255.0)

[Steph]

I can't help, sorry. If you see that it's transmitting something, I would start debugging with tcpdump.
But maybe someone else has a better idea.

[Mihai-Florin.Necula]

I can't help, sorry. If you see that it's transmitting something, I would start debugging with tcpdump.
But maybe someone else has a better idea.

Thanks Steph, I will try this over the next weekend. Today was a free day and I tried to streamline my network (full of all kind of wireless devices with all kind of default settings).
I made everything fit into 192.168.1.xxx including the router so I can keep the subnet mask of the router to 255.255.255.0.
Also new firmware for the router, shut everything out and tried only to connect the station as the only device. Nothing actually worked  and the station is unfortunately still unreachable (no ping reached it even with numerous resets)

As this was an issue which degraded over time I presume there must be an malfunction either in the router or in the board itself (the router seems to provide dhcp services to other devices and is quite fast with handling my connection). Will also try to take the station to a friend so I can test it on his router.

[Steph]

You could try an "arp -a" on the command line. If your computer received something from the station it would be in the arp cache.

[cutty]

You could try an "arp -a" on the command line. If your computer received something from the station it would be in the arp cache.

or you could simply have a 'failed' IC... stuff happens.

Also, make sure you're trying to access the controller at the IP address assigned by the router... "...235" is the default address ... the router may have given it something like..."149"...
either case, once resolved, tell your Router to assign a static (reserved) address to the MAC id of the controller....

[Mihai-Florin.Necula]

You could try an "arp -a" on the command line. If your computer received something from the station it would be in the arp cache.

or you could simply have a 'failed' IC... stuff happens.

Also, make sure you're trying to access the controller at the IP address assigned by the router... "...235" is the default address ... the router may have given it something like..."149"...
either case, once resolved, tell your Router to assign a static (reserved) address to the MAC id of the controller....

Hi Steph,
I tried the arp -a on the IP and no entries were found.
Checked again the router and DHCP has no trace of the MAC. Station used to have an reserved address but this did not solve the DHCP Failure errors (when they were not permanent) anywhays.
I do also think that maybe one of the IC has gone rogue but I will not know for sure until I will connect the station to another router.

If this is an IC issue I need to replace the discovery board or the other IC-s on the board could be the issue?
From what I recall the discovery board was taking care of the internet connection.

[cutty]

The ENC28J60 is the Ethernet controller...  not the discovery board.

[Mihai-Florin.Necula]

The ENC28J60 is the Ethernet controller...  not the discovery board.

Thanks Cutty, I will have a look on the board and search for an replacement. The IC should not be too expensive.

GOOD NEWS EVERYONE,
I thought about the IC but I also I thought that freezing the station would at least do something.
So I froze the station, dried it quickly to prevent buildup of dew and once there was no dew depositing on the station I hooked it to power.
The display was stills showing -70C (an error as my freezer is not that good) but it connected.

Disabled DHCP on the board side and allocated an fixed IP to both the board and router side.
I hope this redneck type of fix will hold until I have the time to tinker with the board.

So in the end the DHCP error was on the station side. The important thing is that the mystery was solved even if I would not recommend anyone to freeze their station as an temporary fix.
Will let you know how long this fix will hold.

[cutty]

That is great!
Which may indicate a poor solder connection on the Ethernet controller, or associated components. 
Us 'old' techs used a 'freeze' spray of Freon, and its cousins, to narrow such things down to component level.
Good Job!

[Mihai-Florin.Necula]

That is great!
Which may indicate a poor solder connection on the Ethernet controller, or associated components. 
Good Job!

Yeah, thanks!
Once I began thinking about the IC I also thought that there might be an issue regarding soldering and it might be worth it to throw the whole thing into the freezer. On the other hand I clearly recall checking each point with the magnifying glass.

I do expect the issue to return at some point. At least this time I know where to look for the issue.
But for the moment: if it ain't broke don't fix it

Thanks Cutty and Steph for all the support and help!

[Mihai-Florin.Necula]

Because the station was down again for some time (behaving strangely, rebooting, stalling), I finally allocated much needed attention to the issue of the ENC28J60 (after checking all the solder points on the board under the microscope and all seemed OK).

The issue (and the fix) was surprisingly mundane... as I noticed that ENC28J60 was not sitting exactly parallel to the discovery board (one side looked a little bit tilted relative to the socket)
In the end it was just an issue of pushing [ENC28J60 harder in its socket (it seems it got loose a little bit).

I noticed some people just hard soldered directly the ENC28J60 to the board (not soldering the provided socked and pushing the IC in). Regarding the unlikely case of this issue returning, is it preferable to solder the ENC28J60 directly to the board or should I look for a new socked? (I am quite confident the problem should not return as I applied more the sufficient force).