DHCP Lease times - Pros and Cons

[juniorb2000]

Hello again,
Our company HQ in a building with 7 floors each with 2 subnets. One for data and one for voice as we have Voip set up. (The subnets are actually VLANs done on the Nortel switches)

We have one MS DCHP server containing all the relevent scopes for Voice and data and the switches do the work of allocating addresses from the correct scopes to the correspdonding floors. Each floor has approximately 100 PCs.

We only went live with this yesterday(we had Netware DCHP running before) and so far we have experienced no issues. My question is, what are the pros and cons of longer/shorter lease times in our setup? Currently, they are just set the MS default of 8 days. Is this advisable?

Thanks

jR

 

[aftertaf]

means that after 4 days (50% lease) the PCs will attempt to recontact the DHCP server and renew their lease.

700 Pcs...
if they dont move around much, and arent switched off much, and the different ip settings pushed via dhcp to the clients dont change often, then you can make this period longer...

i cant see why not.
eg if you make it 24 days, theyll sit happy with all the same ip info for 12 days without contacting dhcp.
if they are switched off, they'll contact dhcp on reinit anyway... whatever the length!


Aftertaf
________
Regain control of your PC, at

http://www.debian.org

 

[m3the01]

Lowering the ip lease time is usually done when your in a pickle and your short ip addresses but dont have time to correctly develope a new scope.

If they dont move around then yeah, up the time to say 12-16 days.

 

[juniorb2000]

Cheers, they don't move around alot so will probably up the lease time a little. Our scopes go from x.x.x.1 - x.x.x.150 so with only 100 max devices on each floor we should hopefully be ok. When we started migrating the floors and configuring the Nortel switches to use the MS DHCP server, alot of bad_addresses were being created when it tried to dish out addresses that were still leased from the Netware box. I feared we may have to keep manually purging these on the MS box until the Netware leases expired out to avoid running out of addresses, but it reallocated these bad addresses automatically in due time. 3 days in and so far all is looking good. Piece of cake!!

thanks again
jR