[lug] PoPToP connection issue
bdoctor at ps-ax.com
bdoctor at ps-ax.com
Wed Jan 7 13:16:44 MST 2004
I'd definitely put those refuse options in there - I seem to recall it not
working, or that the client would *always* do 40bit MPPE, which is unacceptable.
I also seem to recall patching pppd. I did a strings on it:
7 @vpn:/home/bdoctor/poptop-1.1.4 > strings /usr/sbin/pppd|grep mppe
set_mppe_enc_types
refuse_mppe_stateful
mppe_recv_key
mppe_keys_set
mppe_send_key
mppe_set_keys
require-mppe
+mppe
nomppe
require-mppe-40
+mppe-40
nomppe-40
require-mppe-128
+mppe-128
nomppe-128
nomppe-stateful
mppe %s %s %s %s %s %s%s
and the version:
3 @vpn:/home/bdoctor> pppd --version
pppd version 2.4.2b3
I cannot remember for sure if I patched it though. I think I did?
One thing is for sure - there are a lot of little gotchas that I struggled
through and it was a complete pain. Not having MPPE support in your module
listing is an issue I believe. I know that without the kernelmod patch, nothing
would work properly for me.
Also, without the conntrack modules connections through the device (to the
Internet) would fail. Internal connections would work fine however.
This particular installation fully supports windows clients, including domain
logons, network/smb browsing, the whole bit. Also forces all traffic to go
through the device, rather than a split-horizon type of setup. Naturally,
I cannot remember everything that I did, beyond the pain :)
Also, the kernelmod patch will produce modules, so if you have a working
source tree for the running kernel, you won't have to install a new kernel
image - so doing it remotely is safer than it would be otherwise. This patch
provides the MPPE support.
Another thing that helped me is to run tcpdump, and to run the server in full
debug mode (both options.pptpd and pptpd.conf).
-brad
> Ok. I'm pretty sure that I did all that you said. I found that there
> was a problem in my options.pptpd file i had the option
>
> nobsdcomp
>
> with a "0" at the end of it. i ran pppd manually and it didn't like
> that one bit.
>
> now, when I try to connect, my client gives me the error:
>
> Error 732: Your computer and the remote computer could not agree on
> ppp control protocols
>
> Googling on this error only yields two sites.... Reading the PopToP
> FAQ, it says that there are patches available to make pppd compatable
> with the MSCHAP protocol, but the version on the patches that I found
> are version 2.3.5 while the one that I have is version 2.4.2.
>
> here is an lsmod output:
>
> Module Size Used by Not tainted
> ppp_async 9440 0 (autoclean)
> ppp_generic 24820 0 (autoclean) [ppp_async]
> slhc 6756 0 (autoclean) [ppp_generic]
> agpgart 56664 5 (autoclean)
> parport_pc 19076 1 (autoclean)
> lp 9028 0 (autoclean)
> parport 37088 1 (autoclean) [parport_pc lp]
> autofs 13364 0 (autoclean) (unused)
> 3c59x 30928 1
> floppy 58160 0 (autoclean)
> microcode 4724 0 (autoclean)
> loop 12120 0 (autoclean)
> keybdev 2976 0 (unused)
> mousedev 5524 1
> hid 22212 0 (unused)
> input 5888 0 [keybdev mousedev hid]
> usb-uhci 26412 0 (unused)
> usbcore 79392 1 [hid usb-uhci]
> ext3 91592 2
> jbd 52336 2 [ext3]
> lvm-mod 64672 3
>
> i'm not quite sure why i'm missing all the other modules (or where else
> to get them). I installed all the relevant packages you listed below.
>
> here is my options.pptpd:
>
> ## CHANGE TO SUIT YOUR SYSTEM
> lock
>
> ## turn pppd syslog debugging on
> debug
>
> ## change 'pptpd' to whatever you specify as your server name in
> chap-secrets
> name pptpd
>
> proxyarp
> nobsdcomp
>
> # This option applies if you use ppp with chapms-strip-domain patch
> #chapms-strip-domain
>
> # These options apply if you use ppp with mppe patch
> # NB! You should also apply the ChapMS-V2 patch
> #-chap
> #-chapms
> #+chapms-v2
> #mppe-128
> #mppe-stateless
>
> # These options will tell ppp to pass on these to your clients
> # To use ms-wins or ms-dns in options.pptpd it must exist in
> /etc/resolv.conf
> ms-wins ip.of.wins.srvr
> ms-dns ip.of.dns.srvr
>
> would it make a big difference to add the "refuse" options that you
> have listed in your options.pptpd file? (i'll give it a shot anyways).
>
> thanks for the help and sorry for the long post.
>
> -r
> On Wednesday, Jan 7, 2004, at 12:33 America/Denver, bdoctor at ps-ax.com
> wrote:
>
> > A module listing would be helpful. Here are the relevant modules
> > running on a
> > poptop server:
> >
> > ppp_async 9440 3 (autoclean)
> > ppp_mppe 13944 6
> > ppp_generic 24604 9 [ppp_async ppp_mppe]
> > slhc 6740 0 [ppp_generic]
> > ipt_state 1048 1 (autoclean)
> > ip_nat_pptp 2764 0 (unused)
> > ip_conntrack_pptp 3824 1
> > ip_conntrack_proto_gre 4468 0 [ip_nat_pptp ip_conntrack_pptp]
> >
> > And here is the options.pptpd:
> >
> > ## CHANGE TO SUIT YOUR SYSTEM
> > lock
> >
> > ## turn pppd syslog debugging on
> > debug
> >
> > ## change 'pptpd' to whatever you specify as your server name in
> > chap-secrets
> > name vpn.server.com
> >
> > # Don't need this
> > #nobsdcomp
> >
> > #noauth
> > auth
> > # Tell pptpd to find local interface and put it in proxyarp mode
> > proxyarp
> >
> > ipcp-accept-local
> > ipcp-accept-remote
> > lcp-echo-failure 3
> > lcp-echo-interval 5
> > deflate 0
> >
> > # This option applies if you use ppp with chapms-strip-domain patch
> > #chapms-strip-domain
> >
> > # These options are for use with the OpenSSL-licensed patch
> > # This flavor will be obsoleted ASAP.
> > # NB! You should also apply the ChapMS-V2 patch
> > #-chap
> > #-chapms
> > #+chapms-v2
> > #mppe-40 # both 40-bits and 128-bits encryption bite eachother
> > #mppe-128
> > #mppe-stateless
> >
> > # These options are for use with the BSD-licensed patch (ppp => 2.4.2)
> > # This is the default implementation
> > refuse-pap
> > refuse-eap
> > refuse-chap
> > refuse-mschap
> > require-mppe
> > nomppe-stateful
> > nomppe-40
> >
> > # These options will tell ppp to pass on these to your clients
> > # To use ms-dns or ms-dns in options.pptpd it must exist in
> > /etc/resolv.conf
> > #ms-wins <ip-of-your-winsserver>
> > ms-dns <internal IP>
> >
> >
> > Sample log entry for successful connection:
> >
> > Jan 7 11:37:41 vpn pptpd[12194]: CTRL: Client <ip.address> control
> > connection started
> > Jan 7 11:37:41 vpn pptpd[12194]: CTRL: Starting call (launching pppd,
> > opening GRE)
> > Jan 7 11:37:41 vpn pppd[12195]: pppd 2.4.2b3 started by shmoe, uid
> > 8990
> > Jan 7 11:37:41 vpn pppd[12195]: Using interface ppp1
> > Jan 7 11:37:41 vpn pppd[12195]: Connect: ppp1 <--> /dev/pts/1
> > Jan 7 11:37:42 vpn pptpd[12194]: GRE: Discarding duplicate packet
> > Jan 7 11:37:44 vpn pptpd[12194]: CTRL: Ignored a SET LINK INFO packet
> > with real ACCMs!
> > Jan 7 11:37:44 vpn pppd[12195]: CHAP peer authentication succeeded
> > for username
> > Jan 7 11:37:44 vpn pppd[12195]: MPPE 128-bit stateless compression
> > enabled
> >
> > And then for the setup on the windows client, it is really basic - no
> > custom
> > options, just select maximum security for the connection.
> >
> > Key elements for this to work:
> >
> > mppe support in kernel
> > gre support in kernel
> > conntrack support, as noted above
> >
> > Also be sure to download and apply the kernelmod package. It won't
> > work until
> > you do that.
> >
> > Best of luck!
> > -brad
> >
> >> hey guys,
> >>
> >> i'm lost, basically cause i've never set up a VPN server before, but
> >> i'm trying to set one up using PoPToP on WhiteBox Linux. I've patched
> >> the kernel and installed all the right stuff and edited the right conf
> >> files per the RedHat installation instructions on the poptop.org
> >> website. But, when I try to connect a Win2k client to the server I
> >> get
> >> this:
> >>
> >> Error 619: The specified port is not connected.
> >>
> >> here's what is in the logs:
> >>
> >> Jan 7 09:44:38 hostname pptpd[1823]: CTRL: Client home.ip.add.ress
> >> control connection started
> >> Jan 7 09:44:38 hostname pptpd[1823]: CTRL: Starting call (launching
> >> pppd, opening GRE)
> >> Jan 7 09:44:38 hostname pptpd[1823]: GRE:
> >> read(fd=5,buffer=804d5a0,len=8196) from PTY failed: status = -1 error
> >> =
> >> Input/output error
> >> Jan 7 09:44:38 hostname pptpd[1823]: CTRL: PTY read or GRE write
> >> failed (pty,gre)=(5,6)
> >> Jan 7 09:44:38 hostname pptpd[1823]: CTRL: Client home.ip.add.ress
> >> control connection finished
> >>
> >>
> >> this doesn't make much sense to me. I don't have much experience with
> >> GRE, so I'm a little lost. The only ideas that I have is to disable
> >> GRE in the kernel and recompile, but, I'm working from home today (to
> >> test the VPN) and don't really wish to recompile and test a new kernel
> >> remotely :)
> >>
> >>
> >> thanks for help in advance.
> >>
> >> -r
> >>
> >> _______________________________________________
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> >>
> >
> > --
> > Brad Doctor, CISSP
> > _______________________________________________
> > Web Page: http://lug.boulder.co.us
> > Mailing List: http://lists.lug.boulder.co.us/mailman/listinfo/lug
> > Join us on IRC: lug.boulder.co.us port=6667 channel=#colug
> >
>
> _______________________________________________
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--
Brad Doctor, CISSP
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