Multiple-Connecting to Second Life

Hi everyone, maybe someone can help me and my roommate with an issue we're having.

We've both just started playing Second Life, and we share a (Time Warner) cable internet connection in our house. However, we've discovered that for some reason the game won't let both of us log in at once. If I'm logged in and he tries to log in, he gets stuck at the "verifying protocol" message and then gets kicked out with a "Cannot connect to server" error. As soon as I log out, he is able to successfully log in.

Does this have something to do with shared IP addresses or something? Is there any way around this problem, or are we stuck taking turns?

Thanks for anyone who can help!

-Craig

If you are using a linksys router that is probably your problem.

Thanks for your replay. We're actually using a Netgear 4-port router. In what way might a router cause the problem? Is there any way around it?

Probably something to do with their implementation of NAT, or something wacky with the built-in firewall settings. I know my Linksys router wouldn't let Hazel and I both connect at the same time; one of us would be online, the other would connect, and we'd both lag-freeze ourselves off the system.

Having switched to a D-Link four-port router, all our problems went away. I like D-Link.

You may want to check for firmware updates for your router... that may perhaps correct the problem. Or mayhaps contact the manufacturer and see if they have any advice?

Would tweaking the MTU values for the computers involved have any positive effect on this, anyone?

Craig,

Do the following on one of the computers:

Look for the Second Life Icon on the Desktop
Right Click on it and select properties
Select the shortcut tab

Target should read: (depending on your default install)

"C:\Program Files\SecondLife\newview.exe"

add: -port 13000 (outside the quotes)

So it now reads:

"C:\Program Files\SecondLife\newview.exe" -port 13000

Click OK

You should be able to connect from both PCs.

What was happening is that both your PC's were trying to use the same UDP port and NAT could not handle it.

Just make sure when there are SL patches or upgrades, that you go in there and change the port again.

tito

Woohoo! Thanks Tito, that worked perfectly and we're now both logged in. Looking forward to exploring SL. And thanks to everybody else who gave advice as well!

Craig

Where the heck did you find that out, Tito?

Excellent! Thanks!

Very useful post, thank you Tito. I don't have two clients up yet, but I might, one day.

By the way, your post could be interpreteted as blaming NAT for the problem, but that would be inappropriate. While very early versions were somewhat limited, for many years now NAT has been able to handle multi-client UDP just fine.

There is an extensive set of RFCs and other documents to advise developers on how to write networked applications that work transparently across NAT for an arbitrary number of client machines. One effective approach here would have been to start the UDP dialogue from the client end for each port used, so that the router can remap each client port before the server sees it.

Unfortunately, picking a fixed base port is precisely the sort of approach which doesn't work transparently through NAT, and that is why LL is providing the "-port NNN" kludge. Very useful as a solution of course, but it indicates that they chose a bad networking model to start with.

Oh well, at least we're given a way around it, which is great.