SV: SV: Failover question

David W. Hankins David_Hankins at
Wed Oct 11 20:30:55 UTC 2006

On Wed, Oct 11, 2006 at 09:51:33PM +0200, Lars Jacobsen wrote:
> OK,  but is there really a problem when you don't have failover configured
> on these specific one lease pools ? Thought that it might work.

Once a client with identity A gets the lease active on one or both
servers, a client with identity B will be ignored until that lease
expires by one server, and probably won't be ignored by the other
server, but may be ignored if client A managed to get both servers
to move the lease to active.

It's not it's asking for a lot of the same
trouble that plagues one-lease dyanmic ranges (but at least that's

> As an ISP its hard to make this selection based on what client/PC the
> costumer hooks on to his dedicated port on our network. Because the product
> we sell is he always get the same IP no matter what client/PC he connects.
> The CID/RID on the other hand is fully under our control. That's why we try
> so hard making the "semistatic"* leases CID/RID based.

Some folks have made mods to dhcpd so clients are identified by the
relay agent option of their choice istead of the actual client
identity, then use normal dynamic ranges.

We intended to produce similar functionality for entirely unrelated
reasons in 3.1.x, but the 3.1.x release mark was drawn long before
that feature was anywhere near ready.

You have a lot of options and none of them are any good.

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