Requests from one server through another for specific domains - how?

Question

ubuntu

Hello!

Given. There are two servers: Application Server (aka K) and ServerGate (aka P), both rooted, Ubuntu 18.04 LTS. There are several apis (bots) on the Application Server that sometimes access the Telegram servers. It does not have an Application Server in Russia and access to Telegram servers, but it does have ServerGate abroad.

Question . How to configure the network so that requests only to Telegram services from ServerApplication go through ServerGate?

What have you tried.A VPN server (IPSec/Cisco) is already configured and running on ServerGate, and the first idea was to simply connect the Application Server to ServerGate as a vpn client (even if all outgoing traffic at first). What was a mistake, because ssh immediately cut off and I could no longer access the Application Server (this is to the question of my knowledge of networks).

I read several manuals on this topic (for example, once or twice ), but they either set up a channel at certain addresses (I assume that Telegram changes them periodically or can do it), or cuts off my ssh access to the Application Server for good during the setup process .
Perhaps I missed somewhere a good manual on this topic - then send it, please.

Additional question. Most manuals use OpenVPN for this purpose. Are there any pitfalls if there is a need to use IPSec / Cisco in parallel with OpenVPN on the same server?

Answer 1

In telegram, it is possible to specify work through a proxy.
There are instructions on the internet on how to set up a proxy server.
You set up a proxy for telegram on P, on K you set up the telegram client (bot) to work through a specific proxy. You can make a proxy with authorization, or even make access by IP address so as not to distribute it.
PS abbreviations make your question half unreadable.