My french DSL ISP (dynamic IP) uses a Kro$oft protocol (much-hated by mac users) thats called PPTP or VPN (sort of tunneling) instead of DHCP. To get connected under X i had to compile pptp-darwin (with some tweaking) and set up ppp conf files manually. Each time i want to get online, i got to su root, load the ppp kernel extension, pptp to my modem, and change the routing to my using "route delete default" then "route add default ip-adress-i-just-got" (not very cool for background stuff like apache, software update and time sync). That means that the Networking system preferences are unuseable, and I guess these settings -that i cant change without rebooting- are passed to Classic 
1) How can I have pptp started with OS X ? I'm looking for some boot script, but i dont know where the network is launched, and "where" to customize safely... I read in /etc/rc I'd better use a startup items folder. I wonder if they are talking about user's startup items; if so, that doesnt help me much
2) How to set up networking prefs or something else so I can use classic internet apps ?
The error message says that my settings dont allow me to access subnets...
BlueG3/400/256/9GB SCSI/40 GB IDE
Public Beta + Developer Tools

1) How can I have pptp started with OS X ? I'm looking for some boot script, but i dont know where the network is launched, and "where" to customize safely... I read in /etc/rc I'd better use a startup items folder. I wonder if they are talking about user's startup items; if so, that doesnt help me much
2) How to set up networking prefs or something else so I can use classic internet apps ?
The error message says that my settings dont allow me to access subnets...
Code:
Routing tables
Internet:
Destination Gateway Flags Refs Use Netif Expire
default 193.251.38.1 UGSc 11 29 ppp0
10/24 link#2 UC 0 0 en0
10.0.0.10 0:50:e4:40:7f:4e UHLW 0 0 lo0
10.0.0.138 0:90:d0:3:d3:b UHLW 2 9921 en0 884
127.0.0.1 127.0.0.1 UH 9 4999 lo0
193.251.38.1 193.251.38.232 UH 10 0 ppp0
BlueG3/400/256/9GB SCSI/40 GB IDE

Public Beta + Developer Tools