More iPad and network woes

[Darwock]

This drives me crazy, I am employed as a teacher but as nobody else at my school has any clue about I.T. stuff I end up getting asked to solve all kinds of mysterious problems, all of which leave me with no time to deal with my own job because frankly, I'm a little out of my depth and usually don't see any clear solution.

In this case, we have several iPads which up to last month connected to our wifi router with no trouble. Recently we added 9 new iPad minis to the staff equipment. Now one of the original iPads (and a couple of others) can't connect. Others including mine are fine. Problem iPads can still connect at our other locations.

The wifi router is just consumer grade, a Buffalo thing - its set up in Bridge mode and connected to the main NTT router just to allow us to wirelessly connect our iPads, no other reason. I can access the wifi Buffalo router settings but not the NTT one (dont know the password).

Just for clarity, Buffalo is IP address 192.168.8.8. NTT is 192.168.8.1.

In the Buffalo active client list, I can see my own iPads MAC address but not any of those with trouble (naturally). DHCP settings on the wifi router are all set to auto, and I dont see any MAC filtering or limited numbers of IP addresses, but as I understand it being in Bridge mode makes all those settings redundant, right? There are 14 wireless clients showing up in the router, and 5 or 6 wired clients. Is that too many for a consumer grade wifi router to handle?

The 192.168.8.1 router is showing up as the DNS server on my correctly connected iPad. Is it that one which would be limiting the IP addresses (if there is a limit?). That doesn't make sense to me though because my own iPad can connect, and I get to the office after the guy who can't, so surely he would be allocated an IP address before me.

Any help would be much appreciated, I am baffled and I owe the company big time after trashing their valuable property (see irks thread).

[Insom]

Hmm, without knowing the ins and outs of your network I would say, if the wifi router is just set as a bridge then the main NTT router will be what controls your IP address range. If you can, check to make sure you haven't run out of IP address. Also, check the lease length as well.
We had a situation here where every Tom, Dick and Harry got hold of the wireless password and connected all their mobile phones to the network. This meant that, due to our scope options, we ran out of IP addresses to assign to anything new connecting to the network.

Also, check whether both devices are doing DHCP - you should only have one device issuing out IP addresses.

[EvilBoris]

Maybe check what wireless mode the router is set to. Some iPads don't support some certain wifi protocols and if the router is switching to an unsupported mode then this will cause problems for certain devices

I'd check the wireless bridge, as I son says, it shouldn't be spewing out DHCP addresses .
192.168.8.1 isn't the default buffalo Default gateway, so maybe someone has changed it rather than disabling DHCP altogether on the bridge.

Buffalo products Generally use 192.168.11.1

[Darwock]

Thanks guys. I'm not in the office now but from memory all the DHCP options were set to 'auto'. Should I make extra sure and set them to manual? I thought that wasn't possible without specifying an IP range (but I really am clueless).

As an aside, during my faffing around today, at one point one of the iPads showed a really odd IP address, like 169.224.xx.xx or something, it definitely wasn't in the correct range (and the iPad didn't have a DNS server or any functional connectivity). Is that a clue?

[Mayhem]

What iOS version are all the devices running? There were some known network connection problems over wifi from 8.1 onwards that affected randomly, which I believe should be fixed with the new 8.3 release. We had one iPhone here in our testing pool that utterly refused to connect to our work wifi but would happily connect to my home network. Now I've updated it to 8.3, it appears to be okay again (for now!).

[EvilBoris]

169 IP addresses are usually what you get when nothing is connecting properly. DHCP should be off on the bridge ( I think) and on for the router

[randombs]

Is the Buffalo connected to the NTT router by its WAN port? If so, their DHCP functions won't clash because they're separated from each other.

If by bridge you mean it's working as an access point(just joins wireless stuff to the wired network) and it definitely isn't giving out IP addresses then you may well have hit the limit of the NTT router. But you mentioned the Buffalo shows some wired clients which leads me to believe it could still be acting as a router(especially if it only has 4 ethernet ports!).

Switching off the NTT router would be a good way to test this. Switch it off and disable wifi on your iPad. Enable wifi and see if the iPad gets an IP address. If it does, then DHCP is done by the Buffalo and not the NTT.

As you can't access the NTT router, you could work around the limitation like this:

• Check if the Buffalo has a switch on it for the router function - on/off/auto.
• Connect the NTT router to the Buffalo's WAN port(blue, usually) if it has one, not the regular network LAN ports. This will separate it from the NTT and mean both devices can do dhcp no problem. Seeing as both routers have an 8.x address, it's most likely not running through the WAN socket. If you can do this, flick the buffalo switch to router(or enable it in the settings) and reboot both routers. The only downside to this is that machines connected to the NTT router may not see machines connected to the Buffalo one because they're on different networks.
• You may find it just magically starts working. If not, enable DHCP server(not client) on the Buffalo. Then the buffalo will give addresses to wireless stuff. The buffalo should be set to get an address via DHCP from the WAN side(default method).
• Get ready for your invite to the next nomikai.

There are 14 wireless clients showing up in the router, and 5 or 6 wired clients. Is that too many for a consumer grade wifi router to handle?

I think you can expect around 10-15 wireless devices to work more-or-less comfortably on a typical consumer wireless router. This has no bearing on the number of addresses the router can give out(they're usually set to give out 253 by default), so I don't think this is the problem. You'd more likely have all devices with IPs but dropping out randomly.

The 192.168.8.1 router is showing up as the DNS server on my correctly connected iPad. Is it that one which would be limiting the IP addresses (if there is a limit?).

It's likely. It can be set differently but the likelihood of some tech-savvy person having set up the NTT for DNS and the Buffalo for DHCP is slim(although I do this at home!).

my own iPad can connect, and I get to the office after the guy who can't, so surely he would be allocated an IP address before me.

It depends on what the DHCP lease time is set to. Could be two weeks, could be 24 hours, could be five minutes. How it works is this:

The device asks for an IP, the router checks if one is available and assigns it to that MAC address. If the lease time is set to 24 hours, then that device gets the IP address for 24 hours. If that device is online precisely 24 hours later, the IP is renewed automatically. If not, it's made available for someone else to use. So, if your iPad got an IP at 10am one morning and you come into work at 9am every day, your device will keep its IP because it's online whenever the time limit is reached, even though the guy who can't might be in at 8. Think of the timer in Lost if you watched that.

Now, if he was to get in before you and reboot the routers, he'll get an IP and you may get booted off.

Also, I'm guessing it's all in Japanese? I could post up some screenies to show you how mine works. My Buffalo is set up as a DHCP server with wifi off, running on the same network as my router(which has DHCP off but wireless on because it has better aerials), but the principle is the same.

Lastly, if you can get the model number that might be handy. e.g. WHR-G300N

[Darwock]

Thanks again, lots to ponder there. I am back in on Saturday so I'll try to check it out.

Connect the NTT router to the Buffalo's WAN port(blue, usually) if it has one, not the regular network LAN ports. This will separate it from the NTT and mean both devices can do dhcp no problem. Seeing as both routers have an 8.x address, it's most likely not running through the WAN socket. If you can do this, flick the buffalo switch to router(or enable it in the settings) and reboot both routers. The only downside to this is that machines connected to the NTT router may not see machines connected to the Buffalo one because they're on different network

This strikes me as an issue I can't allow to happen, because the iPads need to print and the printer is handled by the NTT router (it's on 192.168.8.100).

[randombs]

Oh it'll work in that direction but not the other way around, so the iPads can see the printer but it can't see the iPads.

Whatever happens, if you can't disable dhcp on the NTT router your options are limited.

Oh, I forgot one thing: have you tried setting the IP address of an affected iPad manually? Just use the same numbers as one that gets an automatic address, give it a random 8.x IP and see if you can access the internet, etc.

It sounds to me like the NTT router might be handling many devices.

[Darwock]

I did actually try that, and it didn't work, but I was a bit lost with regards to what to enter for DNS servers etc. A correctly connected iPad has three addresses in this field, the first is the NTT router and the other two are mysterious numbers. Should I just mirror them all exactly?

[randombs]

You should be fine with just the NTT router's address but by all means enter all three.

If they're mysterious, they're most likely the ISP's DNS servers, or maybe OpenDNS(which starts 208.x I think) or some other website blocking service. Or if they're something like 8.8.8.8 that's Google. The iPad just tries each one in order until it finds a working server(which should be the NTT one!).

Strange it doesn't work. But then maybe there's some other reason they're having trouble connecting, other than a lack of available addresses. What about phones? Do they work on the wifi?

[Darwock]

Rather annoyingly, it just magically started working.

Checked one of the affected iPads again, it was still receiving a 169 address. I tried putting static IP details in, and this time it worked. I changed it back to auto/dynamic, renewed the lease, and it continued to work. Asked the other staff with troublesome iPads to try again, and miraculously everybody was fine.

It's more frustrating than it is a relief, because I still have no idea what happened or what fixed it.

Thanks for all the advice and suggestions though... until next time...

[randombs]

Although I share your concern - it's worse when you've no idea how it worked and count the days until the inevitable cries of "they're not working again!" - I'm glad it's all running smoothly.