Primary & Secondary DHCP- Question

[Mohammed Zia]

HI Team,

We've got a primary and secondary DHCP setup on our wlan.
Primary dhcp server pool=10.1.1.0/24
secondary dhcp server pool=10.1.2.0/24
My question is, If primary dhcp runs out of IP address, is it going to use the secondary DHCP server?

your inputs are highly appreciated

Thanks

[Rasika Nayanajith]

My question is, If primary dhcp runs out of IP address, is it going to use the secondary DHCP server?

It is not working like that. If you have two different DHCP servers, one of them will assign IP for a client.Clients should renew its IP when it reach half of the lease time.

If DHCP scope running out of IP, then client will face issue getting an IP. If client DHCP request reach both servers, one of them should provide ACK for that request.

HTH

Rasika

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[Mohammed Zia]

Hi Rasika,

Thank you for your quick response.

user----->wlc----(L2switch)vlan 20-----DHCP(server1,server2)

WLC config:-
interface vlan 20:-
primary dhcp server:- server1
secondary dhcp server:- server2

So it means controller is going to send discover packet to both the servers?

Thank you

[mohanak]

Clients will use answer from that DHCP server, where they receive responce first. Second responce will be ignored. So both the primary and secondary dhcp server will send a dhcp offer to the workstation. The workstation will choose one of the offers and confirm it to the server.