The company I work for has a ipsec tunnel to another site that we use to have access to various tools. The vpn and ipsec is set up on a Ubuntu server. All of the tools are accessed through a web browser. All of these work while onsite but people need to use the tools through the vpn this used to work but doesn't any more. When trying to access the websites they act just like there is no website there. I don't know that much of what is going on I am a new sys admin so where could I look for problems. I don't really know where to start on this.
I have the vpn started and connect before trying to access the sites. I am able to use ssh and some of the tools work but others don't. Some of the sites just don't load but there are a few that give a 502 Bad Gateway - Response Error, a bad response was received from another proxy server or the destination origin server