Lightsail Ubuntu PPTP connection not working

Question

I have a lightsail ubuntu 20.04 instance that I am trying to connect to a PPTP VPN as a client. I have setup the PPTP peers file, and I am connecting successfully. However despite this, I find that the resources that should be accessible via the VPN are not available to me.

Below is my peers file:

pty "pptp xxx --nolaunchpppd --debug"
name xxx
password xxx
remotename PPTP
require-mppe-128
require-mschap-v2
refuse-eap
refuse-pap
refuse-chap
refuse-mschap
noauth
debug
persist
maxfail 0
defaultroute
usepeerdns

below is the results of an ifconfig -a call

eth0: flags=4163  mtu 9001
        inet 172.26.2.212  netmask 255.255.240.0  broadcast 172.26.15.255
        inet6 2a05:d01c:b79:700:52ac:439:5044:4157  prefixlen 128  scopeid 0x0
        inet6 fe80::491:a1ff:fefd:c3e8  prefixlen 64  scopeid 0x20
        ether 06:91:a1:fd:c3:e8  txqueuelen 1000  (Ethernet)
        RX packets 176016  bytes 90486122 (90.4 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 116473  bytes 12944080 (12.9 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 834  bytes 72479 (72.4 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 834  bytes 72479 (72.4 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ppp0: flags=4305  mtu 1396
        inet 192.168.122.116  netmask 255.255.255.255  destination 192.168.122.118
        ppp  txqueuelen 3  (Point-to-Point Protocol)
        RX packets 17  bytes 806 (806.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 8  bytes 116 (116.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

is there a routing setup that I need to configure within lightsail, or is there any issue with setup? I would have thought once connected to the VPN successfully I would be able to access resources on the remote network. I have attempted this using my personal windows machine and pinging/creating curl requests to the remote resources which works ok, so I can only assume there is some setup on my end that is incorrect.

Any advice would be appreciated, if there is something i can do to provide additional information please let me know.

Dino

Answer

Hello Dino,

I have tested this scenario, and confirmed that after configuring a PPTP VPN server and connecting to it via the PPTP client from my Lightsail instance, I was able to access resources within the same private network as the EC2 instance where the VPN server was configured. Additionally, outbound connections from the Lightsail instance to the public internet showed that the public IP address of the VPN server was used, when the VPN connection was established.

With that said, can you please provide more detail regarding which resources you expect to be accessible that are not working? Which method are you using to connect to those resources -  are you using a specific command or application? Are the appropriate ports allowed in the Security Group configuration? Note, you may need to adjust the outbound Security Group rules for the instance that hosts the PPTP VPN server, and the inbound Security Group rules for the resources you are attempting to access. Are you receiving a specific error message?

I would also like to request that you generate a debug log for the PPTP connection by using the following command:

pon $peers-file debug dump logfd 2 nodetach

This will help to identify any potential problems that might occur when the PPTP client establishes the ppp0 interface. I look forward to your response.

Lightsail Ubuntu PPTP connection not working

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