Can I have multiple DHCP servers on one network?

[Fahad5796]

is it possible to have more than one DHCP server on the same LAN? What are the implications of doing this?

1. What happens if there is more than one DHCP server available? How do my clients know which one to use?
2. How can I have DHCP servers supplying addresses to more than one subnet\network segment?
3. How can I configure multiple DHCP servers to supply addresses for the same subnet.? 
4. We have two ISPs both are providing Internet through PPTP both have different local LAN IP pools . 
5. We want to run both ISPs services on a same infrastructure and provide internet to the client as per their requirement 

[paul driver]

Hello

yes you  can and in fact it's advisable to do so.

One option is to have both  servers with same scops configure but each  servicing half of each scope and having the other half disabled but ready to be made active in case of server failure 

To assit clients in each vlan (different scope on dhcp) to obtain a dh percent lease address you should use a helper address pointing to each server on your core switch/router to forwardnd hp requests to the server

in case of any failure you won't  lose all dhcp service capability but only half and if caught earlier enough maybe none depending on your lease duration values

res

paul

[Tagir Temirgaliyev]

yes I did succesfully

[dukenuk96]

Yes, you can and even should have at least two DHCP servers, but better not on the LAN itself, but configured via relay/helper.

Your questions:

1. Clients will use answer from that DHCP server, where they receive responce first. Second responce will be ignored.

2. Easily, just configure several scopes

3. Also easily, you can configure conflict detection on servers to prevent same address assignment ot different hosts, or you can configure scope failover (aka DHCP cluster). This feature is available both on UNIX-like and Windows systems.

[prajwalmaharjan]

We can have multiple dhcp server but client will choose one with highest/longest lease ip time.