stating NAT and VPN on server with 3 NICs

Question

i have a server with 3 NICs. 1st NIC is for inside office network and its ip is 192.168.135.1. 2nd NIC is for my unlimited internet and its ip is 192.168.31.1. 3rd NIC is for internet connection with valid public ip and its ip is 192.168.1.100. (i have DHCP and DNS on my server too). i start NAT for 2nd NIC in routing and remote access and now my clients inside office can access internet. now i wanna start vpn so clients outside office can access my server and its resources. i setup everything and vpn conncetion works fine from outside of office. but the problem is as long as i start vpn service on my server the clients inside office can reach internet through 3rd NIC which is not unlimited. and when i disconnect the 3rd NIC cable then internet swith bach to 2nd NIC. (i start NAT for both 2nd and 3ed NICs, and do port forwarding on 3rd NICs NAT and also turn on DMZ on modem with valid public ip) can someone help me how to setup internet so ouside clients ca connect to server through 3rd NIC and inside office clients connect to internet through 2nd NIC?

Answer 1

Hello there,

This issue may occur if you configure the VPN connection to use the default gateway on the remote network. This setting overrides the default gateway settings that you specify in the Transmission Control Protocol/Internet Protocol (TCP/IP) settings.

To resolve this issue, configure the client computers to use the default gateway setting on the local network for Internet traffic and a static route on the remote network for VPN-based traffic.

https://learn.microsoft.com/en-us/troubleshoot/windows-server/networking/cannot-connect-to-internet-vpn-server

This article describes how to set up routing and remote access for an Intranet. https://learn.microsoft.com/en-us/troubleshoot/windows-server/networking/set-up-routing-remote-access-intranet

Hope this resolves your Query !!

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