DHCP Multi Site Lease Time

[MarkatLMFJ]

Howdy All,

Ok, I have a 9 site network, switching to DHCP from static IP addressing partly to accomidate the growing number of laptop users I have, partly so that when we change the network around we don't have to hit every machine every time; some computers for instance have a DNS server that has not existed in 2 years.

So we've added the helper entries to the routers and have all the scopes setup BUT some of the laptop users when they go between sites, when they request an IP address they get the one from the other store. When I look in DNS the lease is still active so they are getting that one again and hence, they can't do anything.

I've temporairly solved this by changing the lease time to 1 hour and telling them that it takes an hour from the time they turn off their machine until they can use it in another location.

Ok, I think we can work with that, how much additional network traffic am I going to be having with an hour lease time? Any way to fix the problem I'm having with longer lease times.

Mark L.

 

[pgaliardo]

Not sure if this helps you, but could you write them a quick batch file with ipconfig/release; ipconfig/renew commands. Maybe give them a shortcut to it on their desktop. Then instruct them to run the batch file whenever they switch locations?

 

[ADB100]

Have you configured SuperScopes since this is normal behaviour with SuperScopes. If you haven't your DHCP servers should recognise the clients have moved locations (first-hop router with the Helper configured inserts the IP address of the interface the DHCP request was received on) and NAK the request forcing the client to request another IP address.

HTH

Andy

 

[MarkatLMFJ]

Yeah, they are in a superscope, I'll get rid of that part and see what happens.

Mark