Trouble with WiFi/Broadband

Derek Broughton news at
Mon Feb 11 18:41:58 UTC 2008

Peter Garrett wrote:

> So, it sounds like the wired interface ( probably eth0 ) is getting an IP
> address, and perhaps the wireless interface is not. Also, notice that when
> you leave the system running *after* the 'Magic Hour' it continues to
> work the following day, which suggests that whatever process runs at 4:30
> or 5:30 etc. "fixes" it, but that from a cold start that process (
> whatever it might be), does not run until late afternoon.

>>  It seems, then,
>> to be related to light conditions and/or weather conditions.  But, it
>> wasn't doing this at all until a week ago, and at this rate, come June at
>> this latitude I won't get any work done.
> This is not very likely :)  Much more likely is that there is a process
> that runs at around that time each day, and has the result of "waking up"
> your wireless interface. Probably a "cron" job, but this is a guess,
> really.

Two things come to mind - one the DHCP server (presumably on either - or
both - the wireless router and the broadband modem) won't serve up a new
address between certain hours (most likely because it really isn't running)
or the wireless router has been configured to block certain actions at
certain times of day.  Most wireless routers can do something like that, so
it's where I'd want to look first.  It could be blocking broadcast
packets - which are needed for DHCP - or specifically blocking your wifi
card (or all except a certain wifi card) from using specific ports.

Normally, there would be a DHCP server on the router and the modem, and you
could just turn off the one on the router to make sure the addresses are
served by the modem (in that case, the modem and router should share the
same subnet, eg, 192.168.0.x)
> Another suggestion: when the wireless is "down", what happens if you issue
> sudo dhclient  ?

replacing ? with the name of your interface :-)

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