Question

Hello everybody

I have a problem with a PPTP VPN Client on a RUT950.(last FW version)

4G internet connection with a Telecom Italia SIM.

This is the log:

Tue Nov 29 15:34:33 2022 kern.err kernel: [  399.348316] pptp-varco: recursion detected                 

Tue Nov 29 15:34:34 2022 kern.err kernel: [  400.366388] pptp-varco: recursion detected                 

Tue Nov 29 15:34:35 2022 kern.err kernel: [  401.388172] pptp-varco: recursion detected                 

Tue Nov 29 15:34:36 2022 kern.err kernel: [  402.410577] pptp-varco: recursion detected                 

Tue Nov 29 15:34:36 2022 user.notice mwan3-hotplug[20859]: mwan3 hotplug on varco not called because int

erface disabled                                                                                         

Tue Nov 29 15:34:37 2022 kern.err kernel: [  403.430867] pptp-varco: recursion detected                 

Tue Nov 29 15:34:38 2022 daemon.info pppd[20663]: No response to 5 echo-requests                        

Tue Nov 29 15:34:38 2022 daemon.notice pppd[20663]: Serial link appears to be disconnected.             

Tue Nov 29 15:34:38 2022 daemon.info pppd[20663]: Connect time 0.1 minutes.                             

Tue Nov 29 15:34:38 2022 daemon.info pppd[20663]: Sent 6098704 bytes, received 0 bytes.                 

Tue Nov 29 15:34:38 2022 daemon.notice netifd: Network device 'pptp-varco' link is down                 

Tue Nov 29 15:34:38 2022 daemon.err pppd[20663]: MPPE disabled                                          

Tue Nov 29 15:34:38 2022 daemon.notice netifd: Interface 'varco' has lost the connection  

After taking the IP from the VPN server this error appears and the connection drops. It tries again to establish a connection but the same scenario repeats.

can someone help me?

thanks

Comments

thanks for your support

Answer 1

I would like you to try the following:

In order to avoid recursive routing issue, try placing mobile interface in a separate routing table. To do this, login to the router's WebUI, navigate to Network -> Interfaces section, edit mobile interface settings, switch to Advanced settings tab and add, for example 10, to IP4 table setting field, as in a picture below:

Comments

It works!

Thaks for your support!

Answer 2

Hello,

I would like you to attach a troubleshoot file to your question. Please, replicate the issue, then access router's WebUI, go to System -> Administration -> Troubleshoot section and download troubleshoot file from there. 

Best regards,

Comments

Sorry the first file has no VPN active.

the other file ha VPN ON

Thanks

---

Hello,

I will need additional details.

First, what is the device, operating as a PPTP server?

Would it be possible to receive server configuration details in a private message?

Next, I would like you to login to the router via SSH and execute the following commands:

• echo "debug" >> /etc/ppp/options.pptp
• /etc/init.d/network restart

This will enable additional PPTP logs for deeper inspection. Then wait a few minutes and generate another troubleshoot file.

Best regards,

---

Ok. I reset the updated firmware and send you a message as requested.

In the meantime I did some tests with an older firmware. 00.06.07

The VPN stay UP for 1.9 minutes then the connection terminates. The log is this:

Sat Dec  3 08:51:51 2022 kern.info kernel: [ 1104.530000] pptp-varco: renamed from ppp0       

Sat Dec  3 08:51:51 2022 daemon.info pppd[16831]: Using interface pptp-varco                  

Sat Dec  3 08:51:51 2022 daemon.notice pppd[16831]: Connect: pptp-varco <--> pptp (89.39.226.1

90)                                                                                           

Sat Dec  3 08:51:54 2022 daemon.notice pppd[16831]: CHAP authentication succeeded             

Sat Dec  3 08:51:54 2022 daemon.notice pppd[16831]: MPPE 128-bit stateless compression enabled

Sat Dec  3 08:51:54 2022 daemon.notice pppd[16831]: local  IP address 10.242.1.101            

Sat Dec  3 08:51:54 2022 daemon.notice pppd[16831]: remote IP address 89.39.226.190           

Sat Dec  3 08:51:54 2022 daemon.notice pppd[16831]: primary   DNS address 195.62.160.0        

Sat Dec  3 08:51:54 2022 daemon.notice pppd[16831]: secondary DNS address 46.255.86.255       

Sat Dec  3 08:51:54 2022 daemon.notice netifd: Network device 'pptp-varco' link is up         

Sat Dec  3 08:51:54 2022 local1.info gsmd[8179]: gsmd send: 'AT+QCSQ=1' (10)                  

Sat Dec  3 08:51:54 2022 local1.info gsmd[8179]: gsmd get: 'OK' (2)                           

Sat Dec  3 08:51:54 2022 daemon.notice netifd: Interface 'varco' is now up                    

Sat Dec  3 08:51:54 2022 daemon.info dnsmasq[9151]: reading /tmp/resolv.conf.auto             

Sat Dec  3 08:51:54 2022 daemon.info dnsmasq[9151]: using only locally-known addresses for dom

ain lan                                                                                       

Sat Dec  3 08:51:54 2022 daemon.info dnsmasq[9151]: using nameserver 195.62.160.0#53          

Sat Dec  3 08:51:54 2022 daemon.info dnsmasq[9151]: using nameserver 46.255.86.255#53         

Sat Dec  3 08:51:54 2022 daemon.info dnsmasq[9151]: using nameserver 217.200.201.67#53        

Sat Dec  3 08:51:54 2022 daemon.info dnsmasq[9151]: using nameserver 217.200.201.66#53        

Sat Dec  3 08:51:54 2022 local1.info hotplug-netifd-netstate[20399]: uci result string: (null)

Sat Dec  3 08:51:55 2022 local1.info hotplug-gsmstate[20406]: envACT: ifup                    

Sat Dec  3 08:51:55 2022 local1.info hotplug-gsmstate[20406]: envDEV: pptp-varco              

Sat Dec  3 08:52:00 2022 daemon.err insmod: module is already loaded - xt_multiport           

Sat Dec  3 08:52:00 2022 daemon.err insmod: module is already loaded - xt_connmark            

Sat Dec  3 08:52:00 2022 daemon.err insmod: module is already loaded - xt_comment             

Sat Dec  3 08:52:01 2022 daemon.err insmod: module is already loaded - xt_length              

Sat Dec  3 08:53:44 2022 daemon.info pppd[16831]: No response to 10 echo-requests             

Sat Dec  3 08:53:44 2022 daemon.notice pppd[16831]: Serial link appears to be disconnected.   

Sat Dec  3 08:53:44 2022 daemon.info pppd[16831]: Connect time 1.9 minutes.                   

Sat Dec  3 08:53:44 2022 daemon.info pppd[16831]: Sent 321940799 bytes, received 152 bytes.   

Sat Dec  3 08:53:44 2022 daemon.notice netifd: Network device 'pptp-varco' link is down       

Sat Dec  3 08:53:44 2022 daemon.err pppd[16831]: MPPE disabled                                

Sat Dec  3 08:53:44 2022 daemon.notice netifd: Interface 'varco' has lost the connection      

Sat Dec  3 08:53:44 2022 daemon.info dnsmasq[9151]: reading /tmp/resolv.conf.auto             

Sat Dec  3 08:53:44 2022 daemon.info dnsmasq[9151]: using only locally-known addresses for dom

ain lan                                                                                       

Sat Dec  3 08:53:44 2022 daemon.info dnsmasq[9151]: using nameserver 217.200.201.67#53        

Sat Dec  3 08:53:44 2022 daemon.info dnsmasq[9151]: using nameserver 217.200.201.66#53        

Sat Dec  3 08:53:44 2022 local1.info hotplug-gsmstate[21169]: envACT: ifdown                  

Sat Dec  3 08:53:44 2022 local1.info hotplug-gsmstate[21169]: envINT: varco                   

Sat Dec  3 08:53:45 2022 user.notice gre-keepalive: Reloading gre-tunnel-keepalive due to ifdo

wn of varco ()                                                                                

Sat Dec  3 08:53:47 2022 daemon.notice pppd[16831]: Connection terminated.     

After no response to echo req connection go down

Anyway, I'll do the tests you indicated with the latest firmware and I'll send you the private message.

thank you for your interest

               

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Does the Sophos has a way to configure a virtual LAN IP for PPTP network interface, or other server related configuration options than just specify IP range? Or at least an option to accept what the client thinks Server's IP is?

Apparently, during current connection establishment phase, Sophos pushes it's WAN IP as remote IP, which causes routing issues, and thus Recursion detected issues.

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This is also one of my doubts because at PPTP is assigned the GW ip of the XG on the WAN.

Unfortunately in the XG configuration I can't find a way to give the PPTP network a proper gateway

I don't understand why a PPTP client on Windows can work with this same configuration

---

I have consulted RnD, if anything can be done to successfully establish the tunnel. Once there are updates, I will post them here.