dhcpcd-discuss

Selecting a "better" offer from two DHCP servers

Shahid Mahmood

Wed May 04 13:26:07 2016

Hi
We have a scenario where we request a custom option, and if the DHCP server
understands the option it returns an offer filled with the value (the
"better" offer). If not, we accept whatever server sends us (the 'simple'
offer).

But in some cases, there are two servers. One sends the "better" offer
slightly later (say 1 sec) than the simple offer. We end up using the
'simple' offer.

Is it possible to pick the "better" offer even if it comes after a short
period (1 sec) later than the 'simple' one?

Thoughts:
a) "require" the custom option with -Q. If no offer is received within
certain time, retry without -Q Side effect: delay for networks without
custom option.
b) Somehow fireup two parallel instances, one with -Q. Then deal with the
lease. (not even sure if this is possible)
c) Patch dhcpcd (would like to avoid this)

Response appreciated...

Thanks
-shahid

Follow-Ups:
Re: Selecting a "better" offer from two DHCP serversRoy Marples
Re: Selecting a "better" offer from two DHCP serversBernd May
Archive administrator: postmaster@marples.name