MPD 3.13 PPTP server MTU problems & questions

[Yann Nottara]

Andy Gilligan wrote:

> ----- Original Message ----- 
> From: "Yann Nottara" <yann.nottara at almonde.com>
> To: <freebsd-net at freebsd.org>
> Sent: Thursday, July 17, 2003 6:53 PM
> Subject: Re: MPD 3.13 PPTP server MTU problems & questions
> 
> 
> 
>>but now, what do you think of this ?
>>
>>ng0: flags=88d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST> mtu 1500
>>         inet6 fe80::2b0:d0ff:fee1:4874%ng0 prefixlen 64 scopeid 0x7
>>         inet 192.168.0.10 --> 192.168.0.200 netmask 0xffffffff
>>
>>and here's the part from my mpd.conf that's related to this connection :
>>
>>pptp0:
>>         new -i ng0 pptp0 pptp0
>>         set iface disable on-demand
>>         set iface enable proxy-arp
>>         set iface idle 3600
>>         set bundle enable multilink
>>         set link yes acfcomp protocomp
>>         set link no pap chap
>>         set link enable chap
>>         set link keep-alive 10 60
>>         set link mtu 1460   <----------------- !
>>         set ipcp yes vjcomp
>>         set ipcp ranges 192.168.0.10/32 192.168.0.200/32
>>         set ipcp dns 192.168.0.10
>>         set ipcp nbns 192.168.0.10
>>
>>So, where's the catch ?
> 
> 
> Pretty much the same config as myself, with the exeption that I have:
> 
>     set bundle enable compression
>     set ccp yes mppc
>     set ccp yes mpp-e40
>     set ccp yes mpp-e128
>     set ccp yes mpp-stateless

Sorry, I forgot to include that part but I use it too.

> I've set the MTU to 1460 - as you have, which seems to give me 1396
> when a client connects.
> 
> So far, I've only tested this with Windows XP machines, so I'm not sure
> if anything OS-specific concerning the MTU is negotiated during the
> connect phase, or even if having MPPE enabled would affect it.

My PPTP clients are all Windows 2000 machines.

> I imagine you've tried setting the MTU to other values?

Right, and it's all the same (but now I understand why after reading a 
post from this thread by Archie Cobbs.

> Best regards,
> -Andy

Thanks for you help & comments.

--Yann