Re: [Openvpn-users] Relation of OpenVPN to the system's primary IP address

[Leroy T. <ler...@ve...>]

 After some testing I determined that this was my fault.  i wasn't connecting via the IP address I removed and it wasn't the default route.  It was the subnet-specific route.  In order to change the IP address on a local subnet from OpenVPN:

   
   - Add the new ip first such as ip a a 192.168.1.20/24 dev eth0 (where the current ip address is 192.168.1.10)
   - Update the routing table for the local subnet such as ip r c 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.20 (src was 192.168.1.10)
   - Remove the "current" ip address such as ip a d 192.168.1.10/24 dev eth0 
Hope this helps someone else avoid the same issue.
    On Monday, July 8, 2024 at 01:33:01 AM CDT, Gert Doering <ge...@gr...> wrote:   

 Hi,

On Sun, Jul 07, 2024 at 10:33:35PM +0000, Leroy Tennison via Openvpn-users wrote:
> Was working on a remote system (a local NIC on a network not associated with the one I was on and the OpenVPN tun interface) with a request to change the local system's IP address.  Fortunately I warned the remote staff that I might need their assistance.  I added the new local IP address.  When I removed the previous IP address I lost the OpenVPN connection.  Why did that happen?

With this amount of Information, I would say "because the flobgobble
dingled in the wrong furbark".

As in, this is impossible to answer.  Your OpenVPN connection might have
been talking ("remote 1.2.3.4") to the IP address that you removed.  Or
the system had a default route via that interface's subnet, which broke
when you changed the IP.

To give a bit more meaningful advice, one would need to know more
network details, as in "from which IP/subnet to what IP/subnet did the
NIC renumber", "what IP is the OpenVPN client talking to", "if there is
NAT involved, what internal IP is the OpenVPN server IP natted to",
etc.

gert
-- 
"If was one thing all people took for granted, was conviction that if you 
 feed honest figures into a computer, honest figures come out. Never doubted 
 it myself till I met a computer with a sense of humor."
                            Robert A. Heinlein, The Moon is a Harsh Mistress

Gert Doering - Munich, Germany                            ge...@gr...