MPD Issues - Errors and Mysterious Packet Loss

[Dan Hardiker]

> > [Dan Hardiker]
> > When I connect to the VPN I get a connection status box in my XP sys
tray.
> > If I open that up I get a list of bytes sent and received, as well as
the
> > compression % and number of errors. Compression is always 0% even
through I
> > tell mpd to use compression and have checked its enabled in the VPN
> > connection settings.

> [Michael Bretterklieber]
> MPD (netgraph) doesen't support compression, because it's proprietary and
> patentet, if you realy wan't to have compression (=STAC Compression) then
> you have to buy the sources from www.hifn.com, but usualy you don't need
> compression.

Not having compression is perfectly fine - I was unsure if this was
symtematic of my problem, but its not.

> > If I sit the machine pinging the LAN IP of the MPD server when connected
to
> > the VPN, I start racking up lots of errors. Ive only been pinging for 15
> > mins and the errors is up to 58. Unfortunatly it doesnt tell me WHAT
those
> > errors are, or where to start looking to resolve them.
> >
> > The short of it is that the VPN works, but its paralysingly slow
(throughput
> > has been logged via trafshow as being 300 bytes > 3k a sec on a 256kbit
ADSL
> > upstream ... averaging mostly around 300-400 bps) and could really do
with
> > some pointers as to where to start looking.

I have since managed to find (on the source forge mpd mailing list not
mentioned on the mpd homepages) someone else with an identical problem (who
was advised to install a TCP-MSS patch). It appears that the problem lies
with XP connected to MPD using a VPN. Actually on reflection - it was you
who suggested it!

For reference:
http://sourceforge.net/mailarchive/forum.php?thread_id=3083368&forum_id=32902

> can you please post you configuration and mpd's logfile?

[MPD.CONF]
#
# Default configuration is "myisp"
#

default:
#       log +ccp +ccp2 +ccp3 +chat2 +echo +frame +mp +mp2 +pptp2 +pptp3
        load zen

# Net Connection A
zen:
        load pptpClient0
        load pptpClient1
        load pptpClient2
        load pptpClient3
        load pptpClient4

# Net Connection B
demon:
        load pptpClient5
        load pptpClient6
        load pptpClient7
        load pptpClient8
        load pptpClient9

#
# Mpd as a PPTP server compatible with Microsoft Dial-Up Networking clients.
#

pptpClient0:
        new -i ng0 pptp0 pptp0
        set ipcp ranges 192.168.1.3/24 192.168.1.101/24
        load pptp

pptpClient1:
        new -i ng1 pptp1 pptp1
        set ipcp ranges 192.168.1.3/24 192.168.1.102/24
        load pptp

pptpClient2:
        new -i ng2 pptp2 pptp2
        set ipcp ranges 192.168.1.3/24 192.168.1.103/24
        load pptp

pptpClient3:
        new -i ng3 pptp3 pptp3
        set ipcp ranges 192.168.1.3/24 192.168.1.104/24
        load pptp

pptpClient4:
        new -i ng4 pptp4 pptp4
        set ipcp ranges 192.168.1.3/24 192.168.1.105/24
        load pptp

pptpClient5:
        new -i ng5 pptp5 pptp5
        set ipcp ranges 192.168.1.3/24 192.168.1.105/24
        load pptp

pptpClient6:
        new -i ng6 pptp6 pptp6
        set ipcp ranges 192.168.1.3/24 192.168.1.105/24
        load pptp

pptpClient7:
        new -i ng7 pptp7 pptp7
        set ipcp ranges 192.168.1.3/24 192.168.1.105/24
        load pptp

pptpClient8:
        new -i ng8 pptp8 pptp8
        set ipcp ranges 192.168.1.3/24 192.168.1.105/24
        load pptp

pptpClient9:
        new -i ng9 pptp9 pptp9
        set ipcp ranges 192.168.1.3/24 192.168.1.105/24
        load pptp

pptp:
        set iface disable on-demand
        set iface enable proxy-arp
        set iface idle 3600
        set iface mtu 1500
        set iface enable tcpmssfix

        set bundle enable multilink
        set bundle enable round-robin
        set bundle enable crypt-reqd

        set link yes acfcomp protocomp
        set link no pap chap
        set link enable chap
        set link keep-alive 10 60
        set link mtu 1500

        set ipcp yes vjcomp
        set ipcp dns 192.168.1.250
        set ipcp nbns 192.168.1.11

        set bundle enable compression
        set ccp yes mppc
        set ccp yes mpp-e40
        set ccp yes mpp-e128
        set ccp yes mpp-stateless

[MPD.LINKS]
#
# For our PPTP server
# (Local DNS provides the public IPs for the 2 net connections, zen being
public2 and demon being public)
# I have so far been unsuccessful in getting mpd to listen to 2 IPs at the
same time on the same links

pptp0:
        set link type pptp
        set pptp self armadillo.public2.lan.eorigen.com
        set pptp enable incoming
        set pptp disable originate

pptp1:
        set link type pptp
        set pptp self armadillo.public2.lan.eorigen.com
        set pptp enable incoming
        set pptp disable originate
pptp2:
        set link type pptp
        set pptp self armadillo.public2.lan.eorigen.com
        set pptp enable incoming
        set pptp disable originate
pptp3:
        set link type pptp
        set pptp self armadillo.public2.lan.eorigen.com
        set pptp enable incoming
        set pptp disable originate
pptp4:
        set link type pptp
        set pptp self armadillo.public2.lan.eorigen.com
        set pptp enable incoming
        set pptp disable originate
pptp5:
        set link type pptp
        set pptp self armadillo.public.lan.eorigen.com
        set pptp enable incoming
        set pptp disable originate
pptp6:
        set link type pptp
        set pptp self armadillo.public.lan.eorigen.com
        set pptp enable incoming
        set pptp disable originate
pptp7:
        set link type pptp
        set pptp self armadillo.public.lan.eorigen.com
        set pptp enable incoming
        set pptp disable originate
pptp8:
        set link type pptp
        set pptp self armadillo.public.lan.eorigen.com
        set pptp enable incoming
        set pptp disable originate
pptp9:
        set link type pptp
        set pptp self armadillo.public.lan.eorigen.com
        set pptp enable incoming
        set pptp disable originate

[MPD Log File]
I havent yet worked out how to get mpd into its own log file - have to
modify syslog.conf I believe. My current all.log file is very very big and
has lots of mpd stuff in, but would consitute a 10mb file. Is there anything
in particular you are looking for or would you like me to upload it to a
webserver somewhere?

Thanks for your help - going to try the patch now, will let you know the
results.


--
Dan Hardiker [dhardiker at eorigen.com]
ADAM Systems Engineer
eOrigen Ltd