Laptop fails to reliably connect with school mesh portal

[wad]

At 1CC, it is not unusual for a laptop to fail to associate with a school server on a particular mesh. Yet, when tried for a second or third time, it works.

The laptop is associating fine with the server at the radio level (it shows the proper essid).

Looking at the server logs, it is receiving the DHCP discovery packets, and is responding with an offer. The laptop does not respond with a DHCP request.

I believe that this is probably due to our decreasing the timeout on DHCP discoveries (to speed up scanning through all channels). Unfortunately, this results in some number of laptops forming simple meshes even when a school server is present.

Seen using laptop build 1489 and server build 141.

[wad]

This is still real problem. When testing startup with 29 laptops, around a third of them (seven or eight) didn't find the school mesh portal.

http://wiki.laptop.org/go/Collaboration_Network_Testbed#Test_0317D

http://wiki.laptop.org/go/Collaboration_Network_Testbed#Test_0317E

I suggest backing off on the DHCP timing tweaks added to make trying all three channels faster.

[morgs]

Can you run with logs enabled? presenceservice.log would help to see what happens.

[wad]

This is not a presence service problem. This is a problem with the underlying network. The laptop never uses the DHCP offers sent to it, and decides to join a simple mesh instead.

[wad]

Closed as a duplicate of #4153.