I am trying to understand the network setup that gets configured in my machine everytime I connect to an OpenVPN (Tun mode).
My OpenVPN client creates the following Routes:
Destination Gateway Flags Refs Use Netif Expire 10 10.240.0.5 UGSc 1 1 utun1 10.128.16/24 10.240.0.5 UGSc 1 0 utun1 10.240.0.1/32 10.240.0.5 UGSc 0 2 utun1 10.240.0.5 10.240.0.6 UH 5 1442 utun1
As I understand this '10.240.0.5' is the gateway for accessing VPN resources. However, the gateway for '10.240.0.5' is '10.240.0.6' which is my local IP in this VPN. So the gateway for my gateway is my local IP? I am not following it, for me it seems like a 'loop', but I am clearly missing something.
Another thing is that '10.240.0.5' is a non-pingable address. I find it weird when I cannot ping my gateway (I know in some circumstances icmp might be blocked, but seems not to be the case here).
This is the network interface that gets configured by OpenVPN:
utun1: flags=8151<UP,POINTOPOINT,RUNNING,PROMISC,MULTICAST> mtu 1500 inet 10.240.0.6 --> 10.240.0.5 netmask 0xffffffff
I am not following this thing: '10.240.0.6 --> 10.240.0.5' either, but I assume it has something to do with my confusion with gateway above.
Anyway, this setup works, can anyone please explain how my packages can departure from my machine to the VPN with above mysterious gateway '10.240.0.5'. Is it a hidden virtual IP that OpenVPN configures for TUN VPNs? Any additional material that would help me to gather more deep knowledge about it?
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