How to specify multiple local machines through router port forwarding?

[volcs0]

I'm trying to use a sync backup service to connect to two machines on my home network. I know how to forward incoming TCP connections on a port to one of the machines. But I also need to connect to the other machine. If I can't control the incoming port number, is there anyway to specify to which machine the traffic will go? Something in the server name, for instance?

eg. myhomeip.net/my_local_ip

or something like that...

Or do I need to be able to use a different port for the incoming connection?

Thanks.

[mattkime]

you need a different port for the incoming destination. lets say you want to run a web server on two machines on the same internal network. (http is port 80)

myhomeip.net (goes to machine A, default port is 80)
myhomeip.net:8080 (goes to machine B)

the sync software you're using will need to allow you to supply a port number.

now that i reread your post, i wonder if a more succinct response might have been "no" or "i don't know how to do that"

[volcs0]

This is backup (sync) software. I'm running the server on my work machine, and I want to synchronize to two home machines. The software will let me sync to any machine that's running the software, but I cannot change the port number of the request.

Also, one of the machines I'm trying to sync is a laptop, and it will change IP whenever I move it. So, it would be useful to somehow give this machine some sort of unique identifier, so I can always synchronize to it.

This area is new to me. Is this what "wide area bonjour" is for? Is this something I set up using dyndns? Am googling around trying to learn about this.

[Seacrest]

No, I don't know how to do that.

[comphernation]

volcs0,

You can give any computer a fixed IP address. Google "mac give laptop fixed ip address" to see how. All machines on my home network have been given fixed IP addresses within a certain range (192.168.1.n). Any machines brought in by friends/clients/others will be assigned (by DHCP on my Airport Extreme) IP addresses just above that range.

When I take my PowerBook away from home, I can change the Location (pull down the Apple menu) to something that lets the laptop get an IP address via DHCP from whomever's network I'm using.

While this doesn't solve your whole problem, it may still be useful in an eventual solution.

[Chakravartin]

What backup software are you using?

Perhaps there's a way that you missed to set it to use a custom port.

[volcs0]

I'm using Synk Pro (http://decimus.net/Synk) since Microsoft Mesh seems to have bit the dust with Lion. I am using a work computer as the "server" and then synchronizing with several other machines - another at work, my home mac and my laptop. It is easy to reach out to the other work machine and my home main computer, since they are "fixed." The work machine has a fixed IP and the home machine receives the program requests via a port forward. It has a fixed local IP on my home network.

I just don't know what to do with the laptop.

I might need to run another version of the Synk software on the laptop and have it sync up to one of the other machines. Not ideal, but I can't think of another solution.

I specifically do not want a cloud-based system. I auditioned several programs that do direct connection between machines - either via rsync or p2p (or something else proprietary). I looked at:

http://www.goodsync.com/mac
http://decimus.net/Synk/SynkPro.html
http://www.superflexible.com/
http://jfilesync.sourceforge.net/

Each had pluses and minuses. All seemed fast and capable. I liked Goodsync a lot, but I couldn't figure out how to get the "server" running well. Synk Pro was simply the easiest to set up and use. If I want to add my PC into the mix, I will just have to mount is as an SMB share and sync that way.

Cloud systems do not work for me - not only because of the limitations on file numbers and size, but because many of the data files I use are several hundred megabytes, sometimes gigabytes. Syncing directly between machines is much faster than synchronizing up to the "cloud" first.

[Chakravartin]

I found this in the changelog for v6.5 of that software:

Appending a “:” to the end of the log email server name will cause Synk to use that port (instead of 25) to connect.

'Not sure whether that's the slightest bit helpful, however, as I'm not familiar with the software and it's got terrible documentation. There's no mention of changing ports in the user's guide.

You might have to run a second copy of the server software on the work computer or on a second computer to backup the laptop.