Sorry if this has been asked before, but I can’t search on “DSL” or “VNC” as 3 character strings are too short for the search engine.
Mywife is attempting to work from home by logging into her desktop at work via RealVNC (Virtual Network Connection) using our DSL line. No matter what, she always gets “Authentication failure”. However, if she takes her laptop to work and plugs in to the work LAN, it works. A coworker took the laptop home, and was able to connect using his cable modem account. However, using a DSL account from our house (2 different providers, Earthlink and Verizon, both dynamic IP addressing) either with or without a router, always results in “Authentication failure” (Yes, we’re using the correct password.)
Googling comes up with some people have had a similar problem, and port forwarding in the router is the solution. (1) Tried it, still doesn’t work. (2) Doesn’t explain why I still had the same problem when I wasn’t behind a router.
Any ideas as to (1) a solution and (2) why would VNC behave differently on DSL vs. Cable modem or Ethernet? My research indicates that the authentication is simple challenge/response (prompt/password).
I hope this isn’t your problem, but check with your DSL provider to make sure. Some ISPs consider VPN/VNC type connections to be a “business” application and block the necessary ports on residential lines.
Yet Another Example of companies that don’t “get” the Internet.
My VNC did not work over my cable modem connection until I disabled my firewall. Even though I should have gotten a pop-up indication that the client was trying to get through and a button to allow or disallow it (I was either using Outpost or ZoneAlarm at the time), I never did. Once I shut down the firewall it worked like a charm.
here is the problem with what you are trying to do, your trying to connect to a network who uses a Name Server. Most companies do this for their protection. What it does is create false I.P. addresses to keep out hackers.
When she is at work and types in “ipconfig” the address she sees is more likely a false address.
However, you can Tunnel your way through. See RealVNC’s SHELL documentation.
If you have any “pull” on such issues, have the company look at ROVA - we use that for our VPN and it just works. I’ve never heard of any issues using it on home DSL, wireless hotspots or hotel connections.
The port forwarding doesn’t sound like your answer. This forwards requests that come into your home router to the appropriate machine on your home network. It has not effect on outgoing requests. For this to have any affect on what you are trying to do, you would need to do port forwarding on the router at the place of work BUT, it sounds like if other people can get in, then it is already taken care of.
So, I think the only option you have remaining is that your IP is blocking activity on that port.
If you want to test connecting to another VNC host, IM me.
Thanks to everyone so far. Rereading my OP, I realized I somehow deleted an important piece of information.
I can connect to the work network via VPN with no problem. It’s when I do the second step of attempting to connect to the VNC server on her desktop that I get authentication failures. I’m connecting to her desktop using the works local network’s machine name (not an IP address), so I don’t think the name server is the issue. That seems to be resolving OK.
Firewall: just the built in one in Windows XP service pack 2. It’s a company-owned laptop and I don’t have admin priviledges, so I don’t think I can turn it off. Anyway, a coworker connected using the same laptop via cable modem.
Guess I’ll call Verizon and see if anyone in Bangalore knows if any ports are being blocked.
In the category of ‘is it plugged in’, make sure your NumLock key is not activated. It probably is some port being blocked by your ISP, but double check NumLock, it’s bitten me in the ass on laptops so many times.
I think leandroc76 meant NAT rather than Name Server. But protection from intruders is more of a side benefit of using that kind of NAT rather than the primary reason, which is to share a single public IP address among several computers.
Is her office desktop PC running Windows XP as well? If so, it’s much easier to use the built-in Remote Desktop.
If that’s not an option, there are a few things you might want to check:
Is the VPN configured to be the default path for non-LAN traffic? That can cause DNS failures, amongst other problems.
Can you ping her office desktop when connected to the VPN? It might well be that you are not connected to the same local network when you connect to the VPN. At my company, for instance, we can’t access Tokyo machines if we’re connected to the Toronto VPN, and vice versa, despite the fact that we run a LAN-to-LAN VPN between the two offices.
It’s been a few years since I last used VNC, but does it require a packet-type or port that’s not permitted via the VPN?