Does anyone understand Homehub 2 DHCP??

I wonder if anyone who understands DHCP on the Homehub can help with this one. I am utterly perplexed.....

Background: Homehub 2, BT Vision over Powerline on Infinity 2.

The story so far: Homehub 2 flatly refuses to offer an IP address to my Canon wireless printer with the inbuilt Hub wifi. So, connected a TP-Link wireless AP to the hub and turned off the Hub wireless. Printer now connects fine and gets an IP address from the hub. Most devices connect (Ipods, laptop, Blackberry) but son's Android 'phone again cannot get an assigned IP address from the Hub. On several occasions, however, the Hub also fails to assign IP addresses to anything connected via the WAP. This appears to be highly random and not device specific.

Tried to fix this by also enabling the DHCP server on the WAP, with a defined IP range outside that of the Hub (DHCP on the hub was re-configured to have a mutually exclusive IP address range). So, the Hub should handle the DHCP and IP addresses for wired devices, the TPLink handling wireless IP addresses. All so far so good; everything wireless connects (including printer and Android phone), wired connections all seem OK......

.....until the BT Vision box decides it cannot see the HomeHub any more. It can get an IP address (via the TP Link; the Homehub now flatly refusing to even acknowledge the Vision box exists, never mind assign an IP address) and see the internet, but will not be recognised by the HomeHub. Therefore it will not pause, rewind, record etc.

Turning off the DHCP on the TP-Link and severl re-boots of he Vision box and Hub finally re-establishes HomeHub/BT Vision connection, but then undoes the improved connectivity and IP address assignment on my wireless devices.

How on earth do I get this lot to work properly? Surely the Hub should be able to handle both wired and wireless DHCP provision and connect all my wired and wireless devices, and allow me to connect to my wireless printer over wifi???

Anyone got any idea on this?? It seems rather ridiculous that I need such a contrived setup for a fairly simple home network.......

Solution: ring up BT and get a new homehub sent out

The DHCP will still be handled by the HH with the AP probably hence same issues (albeit different devices)

Fair suggestion!

I thought I was suppoed to gst a HH3 as part of he Infinity 2 upgrade,and have also been promised a black Vision box (still onthe white/silver one) but neither have ever materialised......

Does the HH2 even work properly on infinity?

Might be the isssue

Appears to work on Infinity2, on the back of the white FTTC modem. Speeds on the internet connection are fine, both up and down. (76 up, 19 down).

What model of TP-LINK WAP, usually a WAP does not have a built in DHCP server. The ones that do are NAT routers.

Two DHCP servers on the same physical LAN can cause problems, beyond the original issue with DHCP when you had just the HH2.

But didn't you say it works OK if the two DHCP servers are actually using different subnets, not ranges of the same one which is what the OP has done.

Edited by RobertoS (Wed 10-Oct-12 00:23:43)

It's a TL-WA701ND version 1 WAP.

Had not considered using different subnets as suggested in the later post, just different IP address ranges. Naive question but would the wireless devices (on one subnet) be able to access internet via the hub, which would be on a different subnet?

Two DHCP servers on the same physical LAN sounds a nightmare, as a device will look for any DHCP device and pick the first one.

Now if using MAC restrictions it might solve the problem, but then why bother with DHCP and not just set static IP addresses?

It depends on what default gateway the DHCP server hands out. But if it all works, I think you don't mind the double NAT.