Error 721 A Connection To The Remote Computer
I have FINALLY resolved an ongoing issue with our VPN connections that we have been experiencing for over a year now. I will share these findings with this forum in case others can benefit from our situation. First let me explain the problem. The Problem: It can take up 6 retries for any remote user to successfully created a remote PPTP connection to our servers. Whenever we try to connect it display the following message: Verifying username and password... And it sit there displaying this message for about 30-40 seconds, then it says: "error: 721 The remote computer did not respond." Network Setup: We have two netopia routers on our network. They both have their own separate WAN connection (we use a lot of bandwidth, hence the need for two WAN connections). One RAS server is configured to use one router as it's gateway, and the other RAS server uses the second router as it's gateway. When PPTP connections are made, the connection comes in and back out the same router (this I made sure). We use a multi-NAT for routing service request to internal servers. FTP, WWW, RDP, PCAnywhere, SSL, PPTP, MAIL, etc...all these services are routed to internal servers/workstations. We have approximately 32 public IP addresses, hence why we use Multi-NAT for routing public services to internal servers. Everything works perfectly, EXCEPT PPTP (VPN) connections. We have struggled with this for a year now. For whatever reason, it struggles to make a successful connection to our RAS servers. Like I said, it can take up to 6 retries to successfully connect to our RAS servers (up to 30 retries if the remote user is behind a Linksys router). The Fix: Today, I decided to try something different. I decided to use the router's public IP address for PPTP requests, instead of one of the other public IP addresses our ISP assigned us, and simply forward PPTP (TCP 1723 & IP 47) requests to the internal servers. Therefore, the only difference is that I am using a pingable IP address which happens to belong to the router instead of using one of the public IP addresses I have NATed. For whatever reason, this solved our problem with connecting to the RAS server. We no longer have to retry up to 6 times to successfully connect. Conclusion: I have NO clue as to why I have to use the router's public IP
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