Freebsd MPD PPTP

[Mihai Tanasescu]

Hello,


I'm using MPD4 to establish a PPTP VPN from my FreeBSD 6.2 server to 
some clients and I've started encountering some strange problems.

The connection goes well, everything functions accordingly but after a 
while (very random, can be 5 minutes, 1 hour, 8 hours) I loose 
connectivity (the clients' Windows icon show packet are being sent, but 
nothing is received). A tcpdump on the external interface shows no 
packets going out and the same for tcpdump on ng0 (although I'm not sure 
if it should display something here).

For what I've seen the ip address on the ng0 interface disappears.

My config looks like the following:

FreeBSD cs.duras.ro 6.2-RELEASE FreeBSD 6.2-RELEASE #0

- standard kernel
- rc.conf: mpd_enable="YES"


mpd.conf
pptp1:
        new -i ng0 pptp1 pptp1
        set iface disable proxy-arp
        set ipcp ranges 192.168.1.129/32 192.168.1.130/32
        set iface route 192.168.1.130/32
        load pptp_standard

pptp_standard:
        set iface idle 0
        set iface disable on-demand
        set iface enable tcpmssfix
        set bundle disable multilink
        set bundle enable compression
        set bundle enable noretry
        set bundle max-logins 0
        set link no pap chap
        set link enable chap
        set link keep-alive 0 0 // tried before with 10 and 60 and now 
I've disabled the keepalives
        set link max-redial -1
        set link yes acfcomp protocomp
        set link enable chap-md5 chap-msv1 chap-msv2 chap
        set link mtu 1460
        set link mtu 1460 //here I also tried without these
        set link mru 1460 // here I also tried without these
        set link latency 0
        set ipcp dns dns-ip-address
        set ipcp yes vjcomp
        set ccp yes mppc
        set ccp yes mpp-e40
        set ccp yes mpp-e128
        set ccp yes mpp-stateless
        set pptp disable delayed-ack

mpd.links

pptp1:
       set link type pptp
       set pptp self my-server-ip-address
       set pptp enable incoming
       set pptp disable originate
       set pptp disable windowing

I'm also using pf for NAT:
scrub in all fragment reassemble no-df max-mss 1452
#nonat = local table with lan ip addresses
nat on $ext_if from 192.168.1.128/25 to ! <nonat> -> ($ext_if)

I get no packet errors during the communication.

Can anyone help in debugging this ?


Thanks,
Mihai