Comments on: PPTP using Poptop on CentOS 5 http://blog.doylenet.net/?p=17 Blog of a system administrator Wed, 18 Aug 2010 01:36:18 +0000 http://wordpress.org/?v=2.9.1 hourly 1 By: Setting up PPTP/GRE Gateway behind NAT using IPTables | HeXagon's Hut http://blog.doylenet.net/?p=17&cpage=2#comment-2161 Setting up PPTP/GRE Gateway behind NAT using IPTables | HeXagon's Hut Sat, 27 Mar 2010 02:54:54 +0000 http://blog.doylenet.net/?p=17#comment-2161 [...] you need help getting ppp and pptpd installed, check out this blog post, however substitute the networking rules for the ones listed here. VN:F [1.8.6_1065]please [...] [...] you need help getting ppp and pptpd installed, check out this blog post, however substitute the networking rules for the ones listed here. VN:F [1.8.6_1065]please [...]

]]> By: Will http://blog.doylenet.net/?p=17&cpage=2#comment-2060 Will Mon, 15 Mar 2010 18:50:36 +0000 http://blog.doylenet.net/?p=17#comment-2060 Thanks so much! I finally got my VPN server working. Just wanted to add that the VPN client might have trouble connected if they are running a local firewall like symantec. Thanks so much! I finally got my VPN server working.

Just wanted to add that the VPN client might have trouble connected if they are running a local firewall like symantec.

]]> By: Need help with PPTPD on centos 5 server - Hosting Blog http://blog.doylenet.net/?p=17&cpage=2#comment-1715 Need help with PPTPD on centos 5 server - Hosting Blog Fri, 12 Feb 2010 23:43:48 +0000 http://blog.doylenet.net/?p=17#comment-1715 [...] The installation guide is located here: http://blog.doylenet.net/?p=17 [...] [...] The installation guide is located here: http://blog.doylenet.net/?p=17 [...]

]]> By: Michael Auerswald » VPN on VPS http://blog.doylenet.net/?p=17&cpage=2#comment-1621 Michael Auerswald » VPN on VPS Wed, 03 Feb 2010 23:53:16 +0000 http://blog.doylenet.net/?p=17#comment-1621 [...] Installing PPTPD on CentOS 5 http://blog.doylenet.net/?p=17 [...] [...] Installing PPTPD on CentOS 5 http://blog.doylenet.net/?p=17 [...]

]]> By: ryan http://blog.doylenet.net/?p=17&cpage=2#comment-1292 ryan Mon, 21 Dec 2009 12:29:15 +0000 http://blog.doylenet.net/?p=17#comment-1292 Hi Kay Sorry its been a while since I've gone through my comments. My initial guess would be that a router doing any kind of stateful inspection may not properly support a PPTP VPN. Hi Kay

Sorry its been a while since I’ve gone through my comments. My initial guess would be that a router doing any kind of stateful inspection may not properly support a PPTP VPN.

]]> By: Kay Dub http://blog.doylenet.net/?p=17&cpage=2#comment-1207 Kay Dub Wed, 28 Oct 2009 03:31:49 +0000 http://blog.doylenet.net/?p=17#comment-1207 Hey Ryan, I've got your setup but I've never been able to get past a stubborn timeout issue. I can't nail down exactly how much time needs to elapse, but if you don't send any network traffic through the VPN (on my configuration) for somewhere between 2-5 min, the next time you try to access something in the VPN it just times out. Is there any setting the the VPN I can try or does it have to be something else in my configuration (i.e. maybe a router in the path of the VPN is misconfigured, etc.) As a brutal hack, I just do: ping -t some_server_in_VPN to "keepalive" the connection...ugh. Any thoughts? Thanks... Hey Ryan,

I’ve got your setup but I’ve never been able to get past a stubborn timeout issue. I can’t nail down exactly how much time needs to elapse, but if you don’t send any network traffic through the VPN (on my configuration) for somewhere between 2-5 min, the next time you try to access something in the VPN it just times out. Is there any setting the the VPN I can try or does it have to be something else in my configuration (i.e. maybe a router in the path of the VPN is misconfigured, etc.)
As a brutal hack, I just do:
ping -t some_server_in_VPN
to “keepalive” the connection…ugh.
Any thoughts?
Thanks…

]]> By: ryan http://blog.doylenet.net/?p=17&cpage=2#comment-1205 ryan Sat, 24 Oct 2009 01:46:23 +0000 http://blog.doylenet.net/?p=17#comment-1205 Hi Michael, does this cause pptpd to die or can it still accept VPN clients after the client closes the connection? Also, which VPN client are you using, the default Windows client? It looks like it is terminating the connection successfully but not gracefully. To be honest, I haven't used poptop for a while (I use 2k8 RRAS now) so I can't confirm if this is correct. Hi Michael, does this cause pptpd to die or can it still accept VPN clients after the client closes the connection? Also, which VPN client are you using, the default Windows client? It looks like it is terminating the connection successfully but not gracefully. To be honest, I haven’t used poptop for a while (I use 2k8 RRAS now) so I can’t confirm if this is correct.

]]> By: Michael http://blog.doylenet.net/?p=17&cpage=2#comment-1204 Michael Wed, 21 Oct 2009 20:55:18 +0000 http://blog.doylenet.net/?p=17#comment-1204 Hi, just wanted to say thanks for the helpful article and I wanted to see if anyone else has had this issue. The VPN works great except for when a client disconnects. These errors appear in the log right after the disconnect. My Log: Oct 21 13:04:36 DEV pptpd[19781]: CTRL: EOF or bad error reading ctrl packet length. Oct 21 13:04:36 DEV pptpd[19781]: CTRL: couldn't read packet header (exit) Oct 21 13:04:36 DEV pptpd[19781]: CTRL: CTRL read failed Oct 21 13:04:36 DEV pppd[19784]: Modem hangup Oct 21 13:04:36 DEV pppd[19784]: Connection terminated. Oct 21 13:04:36 DEV pppd[19784]: Exit. Any thoughts ? Thanks in advance Hi, just wanted to say thanks for the helpful article and I wanted to see if anyone else has had this issue. The VPN works great except for when a client disconnects. These errors appear in the log right after the disconnect.

My Log:
Oct 21 13:04:36 DEV pptpd[19781]: CTRL: EOF or bad error reading ctrl packet length.
Oct 21 13:04:36 DEV pptpd[19781]: CTRL: couldn’t read packet header (exit)
Oct 21 13:04:36 DEV pptpd[19781]: CTRL: CTRL read failed
Oct 21 13:04:36 DEV pppd[19784]: Modem hangup
Oct 21 13:04:36 DEV pppd[19784]: Connection terminated.
Oct 21 13:04:36 DEV pppd[19784]: Exit.

Any thoughts ? Thanks in advance

]]> By: ryan http://blog.doylenet.net/?p=17&cpage=2#comment-1178 ryan Mon, 21 Sep 2009 01:01:39 +0000 http://blog.doylenet.net/?p=17#comment-1178 Hi lin, you might have some issues with GRE packets not flowing between your client and the server. Make sure that the GRE protocol is allowed between the server and the client. It could be at either end, so maybe use tcpdump to check the traffic between the client and the server. If you use <code>tcpdump -i eth0 -s 0 -w /tmp/tcpdump.pcap</code> this will dump the contents to a file that you can view with Wireshark later. Hi lin, you might have some issues with GRE packets not flowing between your client and the server. Make sure that the GRE protocol is allowed between the server and the client. It could be at either end, so maybe use tcpdump to check the traffic between the client and the server. If you use tcpdump -i eth0 -s 0 -w /tmp/tcpdump.pcap this will dump the contents to a file that you can view with Wireshark later.

]]> By: lin http://blog.doylenet.net/?p=17&cpage=2#comment-1169 lin Sat, 12 Sep 2009 14:41:52 +0000 http://blog.doylenet.net/?p=17#comment-1169 Thanks for all your help! I've got an authentication problem: (Error Code:619). Could you please help me? thanks! my logs: Sep 12 23:52:19 localhost pptpd[8651]: CTRL: Client 60.240.134.99 control connection started Sep 12 23:52:19 localhost pptpd[8651]: CTRL: Starting call (launching pppd, opening GRE) Sep 12 23:52:19 localhost pppd[8652]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded. Sep 12 23:52:19 localhost pppd[8652]: pppd 2.4.4 started by root, uid 0 Sep 12 23:52:19 localhost pppd[8652]: Using interface ppp0 Sep 12 23:52:19 localhost pppd[8652]: Connect: ppp0 /dev/pts/1 Sep 12 23:52:49 localhost pppd[8652]: LCP: timeout sending Config-Requests Sep 12 23:52:49 localhost pppd[8652]: Connection terminated. Sep 12 23:52:49 localhost pppd[8652]: Modem hangup Sep 12 23:52:49 localhost pppd[8652]: Exit. Sep 12 23:52:49 localhost pptpd[8651]: GRE: read(fd=6,buffer=8059680,len=8196) from PTY failed: status = -1 error = Input/output error, usually caused by unexpected termination of pppd, check option syntax and pppd logs Sep 12 23:52:49 localhost pptpd[8651]: CTRL: PTY read or GRE write failed (pty,gre)=(6,7) Sep 12 23:52:49 localhost pptpd[8651]: CTRL: Client 60.240.134.99 control connection finished Thanks for all your help!

I’ve got an authentication problem: (Error Code:619).
Could you please help me? thanks!

my logs:

Sep 12 23:52:19 localhost pptpd[8651]: CTRL: Client 60.240.134.99 control connection started
Sep 12 23:52:19 localhost pptpd[8651]: CTRL: Starting call (launching pppd, opening GRE)
Sep 12 23:52:19 localhost pppd[8652]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded.
Sep 12 23:52:19 localhost pppd[8652]: pppd 2.4.4 started by root, uid 0
Sep 12 23:52:19 localhost pppd[8652]: Using interface ppp0
Sep 12 23:52:19 localhost pppd[8652]: Connect: ppp0 /dev/pts/1
Sep 12 23:52:49 localhost pppd[8652]: LCP: timeout sending Config-Requests
Sep 12 23:52:49 localhost pppd[8652]: Connection terminated.
Sep 12 23:52:49 localhost pppd[8652]: Modem hangup
Sep 12 23:52:49 localhost pppd[8652]: Exit.
Sep 12 23:52:49 localhost pptpd[8651]: GRE: read(fd=6,buffer=8059680,len=8196) from PTY failed: status = -1 error = Input/output error, usually caused by unexpected termination of pppd, check option syntax and pppd logs
Sep 12 23:52:49 localhost pptpd[8651]: CTRL: PTY read or GRE write failed (pty,gre)=(6,7)
Sep 12 23:52:49 localhost pptpd[8651]: CTRL: Client 60.240.134.99 control connection finished

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