topic Re: Need to adjust my DNS scavenging and DHCP lease for hybrid WFH and On-prem users in Mobile

Need to adjust my DNS scavenging and DHCP lease for hybrid WFH and On-prem users

Joe_Kanaszka — Fri, 12 Sep 2025 02:02:56 GMT

Small 25 person hybrid office. Windows AD.

My users work three days in office on a wired LAN and two days WFH over VPN. Users can choose which days they work from where.

While in the office, users receive an IP address from our DHCP server with a lease duration of 8 days.

While WFH, users receive an IP from our Check Point gateway using the Office Mode IP pool. Some special users receive a static ip using the Check Point ipassignment.conf file

Recently I've been noticing stale DNS entries for our users - not a lot but some. (most of my stale DNS entries are from the static check point IP users)

Our DHCP lease duration is 8 days while DNS scavenge time is a combined 14 days. (No-refresh + Refresh interval) This immediately I know is wrong. My combined scavenge should be equal to or less than my DHCP lease duration.

I have a question though.

1. Currently I do not have an AD DNS Reverse Lookup Zone for my WFH VPN IP range. These WFH IPs are on a different network than my in-office IP range/DHCP scope. These WFH DNS entries of course show up in my AD DNS - Forward Lookup Zone/Domain_name.

My Office Mode IP pool is 10.0.10.1 and my on-prem DHCP scope is on 10.0.100.1

How do you guys set your on-prem DHCP server leases and DNS scavenging to work with users who may migrate between WFH using Check Point Mobile with Office Mode IP and on-premises with a different DHCP assigned IP within a few days?

Thank you!

Re: Need to adjust my DNS scavenging and DHCP lease for hybrid WFH and On-prem users

the_rock — Fri, 12 Sep 2025 02:35:01 GMT

Hey brother,

How have you been? Just thought of something when I read your post...cant recall exact setting now, but there is an option under gateway, vpn clients, office mode, additional options for dns servers (I believe). Are those selected?

Andy

Re: Need to adjust my DNS scavenging and DHCP lease for hybrid WFH and On-prem users

the_rock — Fri, 12 Sep 2025 12:04:52 GMT

Hey Joe,

I attached the setting I was referring to.

Andy

Re: Need to adjust my DNS scavenging and DHCP lease for hybrid WFH and On-prem users

Joe_Kanaszka — Fri, 12 Sep 2025 17:46:22 GMT

Excellent! Tbanks you brother! Have a great weekend!

Re: Need to adjust my DNS scavenging and DHCP lease for hybrid WFH and On-prem users

the_rock — Fri, 12 Sep 2025 18:14:26 GMT

Glad we can help @Joe_Kanaszka

Enjoy your weekend!

Andy