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<div>
<div>Hi</div>
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<div>I am running a failover pair</div>
<div>default-lease-time 43200;<br/>
dynamic-bootp-lease-length 43200;</div>
<div>failover peer "failover" {<br/>
max-response-delay 20;<br/>
max-unacked-updates 10;<br/>
load balance max seconds 3;<br/>
mclt 300;<br/>
split 128;<br/>
}</div>
<div>I have a client that will repeatedly do a DHCPDISCOVER at 50% lease time (rather than a renew), even when it already has an address</div>
<div>in 4-3-6 this is how the flow goes :</div>
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<div>===</div>
<div>* client does discover</div>
<div>* server offers lease of 5 mins</div>
<div>after 2.5 mins :</div>
<div>* client does discover</div>
<div>* server pings previous IP it handed out to client</div>
<div>It gets a response (client is trying to do discover as a way of renewing lease and has not released the old address)</div>
<div>* server marks previous address as abandoned and ignores client</div>
<div>* Client does discover</div>
<div>* server offers new address with lease time of 5 mins (MCLT)</div>
<div>Then we loop round and start again</div>
<div>===</div>
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<div>I happened to have an old device at the back of a cupboard with 4-1-1-p1 on it so just tried against that<br/>
The result is the same, except it does not mark leases as abandoned in the leases file so they get back into pool quicker<br/>
And also on the 4th DHCPDISCOVER the client does it gets a 12 hour lease for the same address offered on 3rd DHCPDISCOVER.</div>
<div>Client packets are the same against both servers, client never sends it's address in the DHCPDISOCVER packet </div>
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<div>I know this client is behaving badly but I am not sure what he expected dhcpd behaviour is, should it just keep<br/>
letting the client eat through addresses or should it treat it like a renew as the old version does (eventually on 4th go) ?</div>
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<div>I know the server will start to use the addresses that were abandoned when it runs out of new leases but<br/>
would rather they didn't all get eaten up in the first place. I am approaching the device vendor too but I</div>
<div>don't hold out much hope there.</div>
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<div>Thanks</div>
<div> </div>
<div>Dave</div>
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