Subject: Re: dhcp/bonding interaction question

From: "Chris Friesen" <[email-masked]>
Date: Tue, 23 Sep 2008 18:15:38 -0600

Jay Vosburgh wrote:
> Chris Friesen <[email-masked]> wrote:
> 	Ok, so your problem (if I'm understanding things correctly) is
> really a chicken-and-egg type of deal.  Your entire network is all
> etherchannel, except for this blade, which needs to connect,
> temporarily, in a non-etherchannel manner in order to boot up and become
> etherchannel-ified (at which point it'll work).

Basically, yes.

> 	One possible problem with hacking the dhcpd to send back out on
> the receiving interface is that (because of the etherchannel) there's no
> general guarantee that the switch paths are symmetrical, particularly if
> a port is down somewhere.

True.

> 	If you're already rolling your own kernels, would it be easier
> to remove the xid interface check from the kernel's dhcp client (i.e.,
> accept the DHCP reply as if it had arrived on the proper interface for
> its xid)?  You could make it into some kind of "netboot_on_etherchannel"
> option.

Yes, this is being considered as well.  Initially I was against it due 
to the possibility of introducing unexpected behaviour, but making it a 
boot argument makes a lot of sense, especially since it would allow for 
more robust behaviour on certain fault scenarios.

Thanks,

Chris