I have 2 different routers, one a 2820n and the other a 2830n, both of which have become very temperamental about issuing DHCP addresses.

the 2830 is a brand new box, and really does not like iPhone 4 devices! when a couple of those are connected, it throws out a laptop!

The other is a 2820 that has been installed for a long time and has just started rejecting connections.. it asks for the passkey, goes through the verifying and connecting, then says it can't connect to this network.. despite the laptop having been connected many times before!

Any ideas/clues to where to start looking?

thanks

C

do you have them connected together or each time you are changing units & so the symptoms you mentioned?

The routers are in 2 different locations, in 2 different cities

C

first case that throw out the laptop try give static ip at all of your devices ... lan>bind ip to mac (not enable strict bind)
see normal mode
http://www.draytek.com/.upload/pdffiles/c0671fe79c540364c1b068d1d87d485b.pdf

for the 2820
-make sure at your network card of your devices (laptop) have the settings (windows so i don't know with linux or apple) to auto connect ... if is not set at auto connect then each time will ask for a key or try remember the password

also if are mobiles , android etc make sure you have set wifi networks as trusted networks in the devices

-try without security and see if have issues, if all are ok then check below

-you can try and for the 2820 give static ip to your devices as mentioned up

-at Wireless LAN >> Security Settings >> mode ... try combination of wpa2/psk or wpa/wpa2 mixed
Wireless LAN >> General Setup ... try n only mode or mixed b,g,n

- you can also try to update its firmware to latest 3.3.7.5 with the *rst* file extention but if you going to update, you must do it with the correct order (see the relased notes) other way confilcts may occur

IMPORTANT NOTE: Do not upgrade directly from 3.3.5 (and earlier) to 3.3.7.5.
Due to differences in the Web UI and functionality the router MUST first be
upgraded to 3.3.5.2 prior to upgrading to 3.3.7.5.

Upgrade your router to Version 3.3.5.2 first, and afterward upgrade the router
to Version 3.3.7.5.