Resolvng IP problem when using RRAS/PPTP

[ErwinC]

Hi

Most of my customers use RRAS for remote clients to dial in with PPTP.
When using RRAS with DHCP it reserves (when booting server) a number of IP adresses from the DHCP server to assign to dial-in clients.
All those adresses are registered in the DHCP server in with the name of the RRAS server, which is logical.

Problem is that when a notebook first connects localy in the company it registers it computer name and get an IP address from the DHCP server. That address stays registered for 8 days (DHCP lease time).
When the user goes home and dials in with that same notebook, it will get a IP adress that the RRAS server has in use but it will not register it's pc name again in the DHCP server.
Therefor when Lan sweeper tries to resolve this notebook it will resolve to the IP address that was given when he was localy connected which does not respond because he has now an ip adress from the RRAS server.

I have the impression that is is not a issue with computers that are always remote and never localy.

How can I sove this, LAN Sweeper does never seem to scan these computers (probably until tey are connected localy).

[Hemoco]

Maybe this will work in the script first an "ipconfig /registerdns" and afterwards starting the lsclient.exe

[ErwinC]

euh yes ofcourse it does not resolve
because the DNS is still pointing to the ip addres the notebook got when working in the office and the notebook is now using a IP address that was requested by RRAS and is not updated in the DNS server..
At this customersite none of the notebooks are scanned they all give reverse lookup failures. The fixed computers that are remote do get scanned because they never work localy.
I found out that when using RRAS VPN the remote computer does not get registred in the DNS server but still get resolved because DNS uses WINS for not resolved addresses (they do get registred in the WINS server). But once the notebook was in the local office it got an IP address for 8 days and it stays registred in DNS and therefor get wrongly resolved.

It's not a LAN Sweeper issue, but you surely must have got this hundred of times. Everybody that uses RRAS VPN and has notebooks that move from remote to localy must have seen this problem.

This is a problem you would not have when using a Client scan.....

I don't see how to solve this nicely, changing the DHCP leasetime to 1 day would make the problem lesser, but is a workaround.

[Hemoco]

Do you get an error (like reverse lookup failed) when scanning?