[milf]

I setup an account through dyndns.org so that I could access my powerbook from work even though I have a dynamic IP address. I downloaded one of the Mac clients that should be auto-updating the dns (??). I was able to connect to it last night, but now that my computer has been asleep for several hours, I can't login any longer.

My question is: Will my Powerbook awake from sleep mode when a telnet/ftp/web/etc request comes in or do I have to keep the system awake in order to maintain remote network availablity? What options do I have?

[milf]

Actually, I'm not sure if the system being asleep is the problem. Here is the error I get when I attempt to connect to my powerbook from work: "192.168.0.2: connect: No route to host". I've only successfully been able to connect from a computer behind the same router; this is my first attempt from an outside machine.

I know I've had issues with my setup before where I was able to stream music to other systems on my internal network, but others attempting to connect from outside were denied. My knowledge of networking and routers is fairly limited, so can anyone help me get this setup correctly? TIA.


[edit]200th post. Woot![/edit]

[ChrisF]

Originally posted by milf:
Actually, I'm not sure if the system being asleep is the problem. Here is the error I get when I attempt to connect to my powerbook from work: "192.168.0.2: connect: No route to host".

You cannot connect to that other computer from outside your LAN by using the 192.168.0.2 IP address. On your home computer, you will need to use something like DNSupdate (search at Versiontracker) in order to keep your IP address up-to-date with DynDNS and if you are using a home router, be sure that the appropriate ports for whatever services you want to use are forwarded to your computer's local IP address. In any case, network services such as ftp/web/telnet will not wake a sleeping computer.

[tooki]

When the computer is asleep, almost all of the hardware is turned off -- including the ethernet interface*.

tooki


* It does have a wake-on-LAN function (called "Wake for network administrative access" on the Mac), which basically is a special circuit in the ethernet chip that is only smart enough to sense a "trigger" and pass that to the power manager. But only a special wake-up packet can wake it, and that can't be done by Telnet!

[jtbowden]

You've got 2 problems here:

1) Your dyndns is not set up correctly. If it is set to 192.168.0.2, you are setting it to an internal network address. This is why you can only connect from computers behid the router. They go to dyndns and ask "where is BOB.dyndns.org?" and they get "192.168.0.2" which works for them because they are on the internal network. When you try this from work, 192.168.0.2 is in your work's local network, so you are either trying to connect to a non-existent computer, or one that is not set up for telnet, etc.

So, like a previous poster said, you need a dyndns client (https://www.dyndns.org/services/dyndns/clients.html). DNSupdate works the best for me. Now, you have to make sure that the client senses your external address and not your internal one (192.168.0.2). There is an option somewhere for this. Once this is all set up, you should always be able to get to your home computer.

1B) Actually, you also need to make sure that your firewall is open to telnet traffic. You need to open the ports on your firewall/router to route telnet/ssh/ftp,etc to your computer. The instructions vary for this, so post more if you need to do this.

2) The computer will not respond if it is asleep. You need to send a "magic packet" to the computer to activate "wake on LAN". This is tricky. I saw a utility/perl script to do this the other day, but I forget where... I will have to get back to you if I find it.

[milf]

I actually got the DNS part working and am able to connect just fine now. I connected this morning when I first got to work with no problems, but trying it now just gives me a blinking cursor. I think it has to do with the system being asleep. I'll search around for info on the 'wake on LAN' feature. Thanks.

[Camelot]

Originally posted by milf:
I actually got the DNS part working and am able to connect just fine now. I connected this morning when I first got to work with no problems, but trying it now just gives me a blinking cursor. I think it has to do with the system being asleep. I'll search around for info on the 'wake on LAN' feature. Thanks.

Wake on LAN isn't going to fix your problem.

As its name implies, Wake On LAN will wake the system when a specially-crafted network packet is sent over the local network.

The nature of these packets is such that they can not be sent remotely (e.g. over the internet), only from another mahcine in the same local network as the machine you're trying to wake - think of a system in an office or a school being woken by a central backup server so that overnight backups can run.

You can not wake a machine using this technique from a remote machine.

Your only other solutions are either to leave the machine on all the time (not asleep) or to get a remote power circuit that can cut the power supply to the machine via telephone or network access. When the power is restored the Mac automatically boots. Sophisticated Circuits ( http://www.sophisticatedcircuits.com/ ) make one such device, but there are others around, too.