Why OVPN fails in some network?

Virtual Private Networks OpenVPN
1

I am on the road a lot, and OVPN works for the most part. But I am having issue connecting from the AirBNB’s wifi network (of which I do not have any control) to my office. Here is the ifconfig response:

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 648  bytes 65770 (65.7 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 648  bytes 65770 (65.7 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1400
        inet 10.25.54.10  netmask 255.255.255.255  destination 10.25.54.9
        inet6 fe80::c2b9:bf87:8d04:6f4d  prefixlen 64  scopeid 0x20<link>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 100  (UNSPEC)
        RX packets 4961  bytes 1318655 (1.3 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 4868  bytes 1545115 (1.5 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.0.215  netmask 255.255.0.0  broadcast 192.168.255.255
        inet6 fe80::27c9:3301:539c:f290  prefixlen 64  scopeid 0x20<link>
        ether 6c:88:14:dd:24:60  txqueuelen 1000  (Ethernet)
        RX packets 30330  bytes 16396777 (16.3 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 25995  bytes 11940047 (11.9 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

I could see the netmask setting of the AirBnB’s wifi is not 255.255.255.0 which we use in my office. What can I do?

Thanks!

Bo

2

Good night from Spain Bo.

I can think of two possibilities:

  1. That the network from which you connect has Firewall rules and has the ports closed.

  2. That from the computer you connect has the same IP range as the network to which you want to connect.

I always tell my Clients to do the following test:

  1. Let them share their mobile connection and try it through it.

If this point works, it is a problem of the connection from which you are trying to connect.

Greetings.

1 Like
3

Thanks Roberto. I am able to connect via my cellphone hotspot / tethering.

Is it possible that that the wifi netmask of 255.255.0.0 resulting in any of the addresses in the range of 192.168.0.0 - 192.168.255.255 be considered “internal to” the wifi, thus confuses the OpenVPN?

4

FYI. It turns out that changing the netmask to 255.255.255.0 fixed the OpenVPN connection.

Bo