Superhub Modem Mode - Can no longer detect WAN IP

MattGarner · 08-10-2013, 20:56

Hi all,

I've been having internet issues for most of the weekend but then around midnight last night it decided to die fully with a 100% packet loss showing on the Think Broadband graph. At first I thought this might have been an issue with Virgin Media in the area.

It turns out the internet connection is fine when everything is directly connected to the SuperHub with modem mode turned off. Since Christmas 2012 I've been using a TL-WR1043ND with the SuperHub in modem mode without any issues but today it's decided it will no longer pick up the WAN IP address. I've tried rebooting both devices, factory settings, different Ethernet cables but with no success. I also tried upgrading the TL-WR1043ND router to the latest firmware available to see if that would have any difference but still doesn't pick the WAN IP. It just puts them all to 0.0.0.0.

Has anyone come across this before or can give me some assistance? Any replies will be much appreciated.

Cheers,

Matt

Kushan · 08-10-2013, 21:01

Not come across that, but try this:

In modem mode (where you have the issue), remove the Coax cable and reboot the device. Leave coax cable removed.
Let it settle for about 5mins (watch the light sequence loop a few times).
Then, without rebooting or switching off the hub, screw the coax back in. Again leave it about 5mins, it should reconnect to the network (Light turns blue). See if that helps.

Sephiroth · 08-10-2013, 21:15

MattGarner hasn't made clear whether or not the Internet drops when the IP address is shown as 0.0.0.0?

There are several reported cases where, for example, Traceroute shows a 0.0.0.0 IP address yet the Internet works.

Incidentally, I boot up the router first then the SH so that it has everything there as soon as it has acquired the internet modem side. Sometimes, though, I have to repair the network connection in Windows by resetting the network adaptor.

MattGarner · 08-10-2013, 21:17

Quote:

Originally Posted by Sephiroth

MattGarner hasn't made clear whether or not the Internet drops when the IP address is shown as 0.0.0.0?

There are several reported cases where, for example, Traceroute shows a 0.0.0.0 IP address yet the Internet works.

Incidentally, I boot up the router first then the SH so that it has everything there as soon as it has acquired the internet modem side. Sometimes, though, I have to repair the network connection in Windows by resetting the network adaptor.

Sorry for not making it clear. The answer to your question is that there is no internet connection when the router and superhub (in modem mode) are connected and doesn't pick up the WAN IP.

I'll try both of your solutions tomorrow when I get the chance to see If I can get it working again.

ferretuk · 08-10-2013, 21:39

If it's been working but now doesn't, something has changed (obviously)! I'm assuming that the SH has good levels and that the connection has no packet loss in router mode?

That being the case either VM have changed something or your router has failed. Try plugging your PC into the SH in modem mode and see if that works. If it does, use the 'Clone MAC' function on the router so that the router's WAN port has the MAC of your PC LAN card and try the router plugged in again...

---------- Post added at 22:39 ---------- Previous post was at 22:19 ----------

Quote:

Originally Posted by Sephiroth

Incidentally, I boot up the router first then the SH so that it has everything there as soon as it has acquired the internet modem side. Sometimes, though, I have to repair the network connection in Windows by resetting the network adaptor.

In modem mode I'd recommend booting the SH first, followed by the router so that the router can acquire a WAN address by DHCP as it starts up...

kwikbreaks · 09-10-2013, 07:28

I have my SH, SamKnows box, and router all in the same powerstrip so they all power up together (but have different boot completion times obviously). I've used several different routers and never seen an issue with acquiring an IP so I'm guessing the conflicting advice given for sequence of powering up is of no real consequence. In cases of difficulty it may be worth trying both.

Sephiroth · 09-10-2013, 07:46

Well, I thought of it like this.

In a normal day, so to speak, VM might shift you onto another line card and your WAN IP must change. The router is on, the modem is on, you are asleep and it all comes back to life with a different WAN IP.

Fairly simples.

ferretuk · 09-10-2013, 08:09

The power up sequence is not relevant to the OP's issue... Turning the router on after the modem will speed reconnection up as its first DHCP request will be replied to and it won't have to back off and try again after a timeout...

Back to the OP's problem however...

Try my suggestion of testing with a PC first. Other tests you can do are:

Check the router WAN config is set to DHCP and not PPPoE or similar. Try selecting a different connection method and then reverting back to DHCP.

If you have a second PC try configuring it to be on a different subnet as you LAN and give your router WAN a static address in the same range. Set the gateway on the second PC to be the WAN address and then try pinging the second PC from a machine on your LAN.

Put the router back to DHCP on the WAN and connect the WAN port to a LAN port. Look at the router GUI and confirm that the WAN port gets an address allocated.

Finally - Have you put your router back on the stock firmware or are you still on DD-WRT? Remember you had a similar issue when you changed to DD-WRT in January...

qasdfdsaq · 09-10-2013, 14:17

Quote:

Originally Posted by ferretuk

The power up sequence is not relevant to the OP's issue... Turning the router on after the modem will speed reconnection up as its first DHCP request will be replied to and it won't have to back off and try again after a timeout...

The first DHCP request should always be replied to, because the modem replies with its own DHCP response if the DOCSIS connection is not yet up. The router will be given a temporary local IP (192.168.100.x) with a short lease of 30 or 60 seconds giving it access to the modem's status page at 192.168.100.1 until the WAN is up properly (if it ever comes up).

This is standard on most, if not all DOCSIS modems, including the Superhub in modem mode. Hence, with a working modem and router, regardless of WAN/DOCSIS/Internet connection state you should never end up without a DHCP assigned address of some sort.

If it does, that would suggest some sort of connectivity issue between the router and the modem (Superhub) or a fault with one or the other.

MattGarner · 09-10-2013, 18:18

Thanks for all of the replies I do really appreciate it. To answer some of the questions in case it happens again in the future for either myself or anyone else.

SuperHub - Directly connected there is a stable connection with no packet loss.
TL-WR1043ND - Using stock firmware

Anyway,

I've been able to fix it with the suggestion about using the "Clone Mac" function on the router. That seems to have done the trick and now I am up and running again. I haven't done it this way before so should I expect any issues with that down the line or should it be okay now?

Cheers,

ferretuk · 09-10-2013, 21:35

Glad that worked for you - The finger of blame points firmly at VM's DHCP server then

You should be fine from now on, unless VM make a further change that breaks things again!

Kushan · 10-10-2013, 09:12

This happens quite a lot from what I've seen, has done for years, particularly if you change devices a lot (So quite a lot of people have this issue when there's an area fault and they try a bunch of different PC's - even after the fault is fixed, the numerous mac address changes cause the DHCP server to not give out a valid IP.

The coax cable thing I described above would generally flush the DHCP cache at Virgin's end, though I've never used it on a Hub.

kwikbreaks · 10-10-2013, 09:17

I've seen that one mentioned before. From what I read each MAC gets an IP reserved for it but there are limited slots available for that and if you exceeed that number new devices won't get an IP. The devices tried earlier should still get the IPs they did orginally though. Unused slots do time out after a few days or TS should be able to manually clear all of them - assuming you get a competent rep of course.

Not applicable in this case though as it looks like only two were tried and that only after a failure.

Teglet · 10-11-2015, 12:21

I have just transferred from BT and was unable to get my SonicWALL TZ210 to connect to my VM SH when in modem mode. After the best part of a day spent with various VM support engineers did not produce any results I found this forum.

My thanks got out to FerretUK for the solution, I would not have tried cloning the MAC address in a million years!!

I now have my Internet and my email back; many thanks.