I have set up a rather simple L2TP/IPsec server with xl2tpd, which has a pool of IP addresses in xl2tpd.conf configured for VPN clients. I now need to assign a certain IP address to a VPN client if that client uses a certain username with correct password. The problem is, pppd is configured to run an auth helper to authenticate users to an Active Directory domain, this way I cannot user chap.secrets file to specify an IP address to a connection that's established with a given user name. More, pppd receives suggested (?) IP addresses from xl2tpd's pool, thus an address is allocated before authentication, and it also seems to ignore the ipcp-accept-remote
directive in options file that technically allows L2TP client to specify their desired IP address, or I'd just set a static IP address in the client's settings. Client in Windows 7.
How can I make pppd assign a certain IP address to a connection after it has been authenticated against Windows AD?
Edit: it looks like that with a configured NTLM auth helper pppd does not ever use chap-secrets file, so anything I enter there is just not used. So, is it plain impossible?