Wireless DHCP issues

[Werner Almesberger]

"Marco Trevisan (Trevi?o)" wrote:
> Ok, I'll send you.

Thanks ! The message contents look healthy. However, there are several
holes in the message sequence, from both sides. Here are all the DHCP
messages from your file:

DHCP Discover - Transaction ID 0x3938652d
DHCP Offer    - Transaction ID 0x3938652d
DHCP Discover - Transaction ID 0x3938652d
DHCP Offer    - Transaction ID 0x3938652d
DHCP Discover - Transaction ID 0x3938652d
DHCP Offer    - Transaction ID 0x3938652d
DHCP Offer    - Transaction ID 0xc2d0fd01	no discover ?
DHCP Offer    - Transaction ID 0xc2d0fd01
DHCP ACK      - Transaction ID 0xe89cfb5a	out of thin air ?
DHCP Request  - Transaction ID 0xe89cfb5a	no offer ?
DHCP ACK      - Transaction ID 0xe89cfb5a
DHCP Discover - Transaction ID 0x8e8a6c7d
DHCP Offer    - Transaction ID 0x8e8a6c7d
DHCP Request  - Transaction ID 0x8e8a6c7d
DHCP ACK      - Transaction ID 0x8e8a6c7d

So there are clearly losses, at least in what your sniffer picked up.

By the way, a tcpdump on the Neo may be a more reliable source for
what's being sent and received. That would also avoid the encryption
problem.

So we come to the usual question: what does iwlist scan have to say
when at the problem places ?

I don't see any reassociations, which would be good. If you check
demsg, are there indeed none ?

Also, do you always get a rapid response with dhclient ? Maybe it's
just some weirdness in Busybox' udhcpc ...

I started to try to reproduce some of the WPA problems that have been
reported, and it seems that, if you kill wpa_supplicant and restart
it, then sometimes (*) there's a continuous stream of associations
rapidly followed by disconnects. This might also explain symptoms
like the ones you're seeing.

(*) Easy to reproduce when I'm not logging anything. Never happens
    while I'm watching carefully. I think I need a book on quantum
    physics :-(

> No this is not the problem... The main issue is that I hardly would be
> able to support the insults of my friends (not exactly tech-people) :D.

Ah, but if it's a pub, then it should open early. So maybe you could
take your geek friends for a debugging session with beers, and then
hide the equipment when the rest shows up ? :-)

Thanks,
- Werner