DNS Scavenging in Schools...

[BentleyMiller86]

Hi all,

 

I currently look after 9 schools, none of which have DNS Scavenging enabled, i'm just after a few pointers please

 

1. What time frame is best to use in a school environment? I don't want to end up killing all the active clients over the summer holidays!

2. Should an active address be deleted, what are the consequences to the client machine?

3. There are some really old records at some of my sites, If i manually delete a DNS entry in Forward Lookup Zones, will it automatically delete all other associated records for this entry?

 

Many Thanks

[3s-gtech]

I stick to the default - 8 day DHCP lease, 4 day no-refresh interval, 4 day refresh interval. The scavenge times combined should equal the DHCP lease time for best results. You can go longer, but there's no real need. Machines will just pick up a new address after the holidays. That's how I've run it here for many years, with no issues there. Our DNS works nicely as a result. Without scavenging turned on, services like SOLUS3, AB Tutor/Impero etc go a bit nuts!

[derf]

Same as post above. Defaults are fine and easy and without it you'll have all sorts of nasties creeping in.

[TechMonkey]

1/ I have 7 days set for both settings, this allows a 14 day window. My understanding is that if a record is deleted it will just be recreated next time the computer boots up. You won't delete anything important and nothing should be locked out. The only case I would set smaller would be a public WiFi setup, where you don't really want DNS hanging around as most users will be long gone. That would be done in conjunction with DHCP lease times.

2/ No consequences, it will get recreated next time it makes a request.

3/ ... I think so. Try one and check!

 

EDIT: Just to add, 7 & 7 is not a personal preference, it is what is set currently and I couldn't tell you why! I'm now looking into 4&4, which would fit in with our DHCP leasing.

Edited April 26, 2018 by TechMonkey

[BentleyMiller86]

Thanks all

 

Ironically we deployed the SIMS update last night and I am now running round like a headless chicken sorting SOLUS and DNS issues out!

 

I will set scavenging up at all my sites this evening now!

[Duke5A]

Do you run KMS over DNS? I do and setup scavenging and it removed my DNS record for the KMS server. For some reason the record isn't created as a static one, so be sure to change that before enabling scavenging.

[BentleyMiller86]

Hi Duke,

 

No I don't bother with KMS, not because i'm lazy, I just haven't got round to it yet but i I will make sure its static when I start setting KMS up in my schools!

 

Thanks for the heads up!