[TriLUG] dhcp from multiple waps
Joseph Mack NA3T
jmack at wm7d.net
Sat Apr 5 14:03:11 EDT 2008
I've got a bunch of waps on the same network, allowing
roaming, running DD-WRT (or similar) and I want the clients
to dhcp. I don't need DNS for the client's name/IP (ie I
don't need dhcpd to update named). WAP coverage overlaps so
I can pull out any single WAP without clients loosing
Currently I'm handling dhcp on the router. Can I handle
dhcp on the waps? Problems I see are:
If I turn on dhcpd on each wap and give each dhcpd a subset
of the IP space then when the client moves to a new wap, and
gets a new IP, its tcpip sessions will be lost.
If I turn on dhcpd on only one wap, and hope that the dhcp
calls make it around the network, then when that wap dies or
is taken off-line, there's no more dhcpd.
There is redundant dhcpd, where two dhcpds on a network
cooperate to hand out IPs in the same address space (it's
not called "cooperative", maybe parallel, I forget). I've
had this running at home, but it never worked well. After a
few 100 dhcp leases were served, one server would wind up
thinking that the other server had all the leases (even
though it didn't) and wouldn't hand out any leases at all. I
had to shutdown the dhcpds, clear the leases files and start
again. Postings to the dhcpd mailing list didn't help and I
found that it was a long standing problem (several years).
As well I don't know if the dhcpd on DD-WRT can do
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
generator at http://www.wm7d.net/azproj.shtml
Homepage http://www.austintek.com/ It's GNU/Linux!
More information about the TriLUG