DHCP lease times - what do you set

[sparkeh]

Just wondering as to fix an issue we are having I was thinking of reducing the lease time and was thinking about the effect.

 

You see, since we started broadcasting our guest SSID every man Jack of the residents around here have tried to hop on for some free wireless. We use the Ruckus guest login page and thus clients get an IP address and load up the login page. Of course they don't get anywhere but the DHCP lease is left behind and these cheeky so and sos are filling up the DHCP server and I have to keep clearing it out - I do add them to the deny filter but its endless.

 

I am going to vlan the network in the future but for the moment I was thinking of reducing the lease time so that they are cleared quicker? I guess this has the effect of increasing network traffic but will we see a noticeable effect?

[IrritableTech]

Our network is VLANed so our domain clients get 8 days (standard windows stuff) and our BYOD VLANs get 8 hours. A device should renew its lease on boot, reconnection or (I think) half way through the lease.

 

It's run smoothly here since its implementation.

[localzuk]

We use the following timings on DHCP:

 

802.1x wireless LAN - 12 hours

Guest wireless - 2 hours

Non 802.1x captive portal wireless - 12 hours

 

Yes, it increases LAN traffic, but overall its pretty much unnoticeable.

[victory2012]

wireless is 24 hours

lan / vlans is 7 days

 

and printers vlan is set not to expire

[Michael]

Ideally if you have a guest wireless, a separate VLAN and IP range is generally the way to go.

 

Normally in a domain environment, it's anywhere between 3 to 7 days. In a guest environment, I'd probably make it no more than 12 hours. A 'genuine' guest wouldn't stay longer than this at any one time.

[sparkeh]

Thanks, yeah I will be vlaning in the future, just wondered if reducing the lease time in the meantime would create extra problems or not.

Looks like I will be doing this for now.

[gaz350b]

We had to go really aggressive with our Guest network and have 30 minute lease times. smartphones are really bad for just connecting to any open wifi if its available.

 

Our BYOD network has 1 hour and enough IP's so everyone can have 1 device, trouble is some people have 2.

[AngryTechnician]

I personally try to avoid configuring even a guest network without a PSK. Our guest network has a simple PSK key (along with the login portal) that is posted on signs through the the buildings, so anyone who needs it can find it, but it does cut down on the chancers.

[GeekyPete]

Wired 7 days, There is little change.

 

Wireless 12 hours. The ip is retuned to the pool everynight but your BYODs are good for that day.