Errno 22: Invalid argument

I'm trying to connect on a VPN serfver I did not configure myself and I'm getting crazy trying to connect to it.

I am able to connect on a VPN server I did setup myself using [hwdsl2/setup-ipsec-vpn](https://github.com/hwdsl2/setup-ipsec-vpn), but the one I did not configure is getting me mad.

I'm stuck here:

```
+ ipsec auto --up L2TP-PSK
002 "L2TP-PSK" #1: initiating Main Mode
003 ERROR: "L2TP-PSK" #1: sendto on lo to ###.###.###.###:500 failed in reply packet for main_outI1. Errno 22: Invalid argument
104 "L2TP-PSK" #1: STATE_MAIN_I1: initiate
010 "L2TP-PSK" #1: STATE_MAIN_I1: retransmission; will wait 0.5 seconds for response
003 ERROR: "L2TP-PSK" #1: sendto on lo to ###.###.###.###:500 failed in EVENT_v1_RETRANSMIT. Errno 22: Invalid argument
010 "L2TP-PSK" #1: STATE_MAIN_I1: retransmission; will wait 1 seconds for response
003 ERROR: "L2TP-PSK" #1: sendto on lo to ###.###.###.###:500 failed in EVENT_v1_RETRANSMIT. Errno 22: Invalid argument
010 "L2TP-PSK" #1: STATE_MAIN_I1: retransmission; will wait 2 seconds for response
003 ERROR: "L2TP-PSK" #1: sendto on lo to ###.###.###.###:500 failed in EVENT_v1_RETRANSMIT. Errno 22: Invalid argument
010 "L2TP-PSK" #1: STATE_MAIN_I1: retransmission; will wait 4 seconds for response
003 ERROR: "L2TP-PSK" #1: sendto on lo to ###.###.###.###:500 failed in EVENT_v1_RETRANSMIT. Errno 22: Invalid argument
010 "L2TP-PSK" #1: STATE_MAIN_I1: retransmission; will wait 8 seconds for response
003 ERROR: "L2TP-PSK" #1: sendto on lo to ###.###.###.###:500 failed in EVENT_v1_RETRANSMIT. Errno 22: Invalid argument
010 "L2TP-PSK" #1: STATE_MAIN_I1: retransmission; will wait 16 seconds for response
003 ERROR: "L2TP-PSK" #1: sendto on lo to ###.###.###.###:500 failed in EVENT_v1_RETRANSMIT. Errno 22: Invalid argument
```

_Note: I obfuscated VPN Server IP to `###.###.###.###`. If you know how to solve this, please poke me._

I'd need a way to gather as much information as possible on the VPN server I'm trying to connect to. I'm only facing this issue on Linux. I am able to connect using MacOS with a `L2TP over IPSec` without special configuration.

I wish I had more debugging tools too for this.