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I am attempting to create an authentication system for my network via Radius. Eventually, I want all machines on the network to authenticate with Radius before gaining access to any other network resources, and I want to be able to log the activity of each machine.

For now, baby steps. I have a Linux server running Ubuntu which is connected to a TP-LINK unmanaged switch. Connected to a TP-LINK unmanaged switch (could this be a problem for me later?), I have a server running Ubuntu with RADIUS successfully installed and radtest working on localhost, a windows laptop running vista, and a Macbook pro.

The switch assigns each machine an IP like this: At least between the Macbook pro and the Ubuntu server, they can ping each other. Now, how would I authenticate with Radius on my Ubuntu server from my Macbook pro?

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The switch does not assign that IP. – MDMarra Nov 15 '11 at 19:55
Yes. is reserved for DHCP autoconfig. And you can't do RADIUS at the switch-port if the switch doesn't do 802.1x. – MDMarra Nov 15 '11 at 19:56
You're looking for 802.1x (aka NAP). Look it up, read up, most OSes support it one way or another. You might want switches that directly support it, depends on your requirements. – Chris S Nov 15 '11 at 19:56
@CalvinFroedge Re: that IP range, Google: APIPA. See also & RFC 3927 @ – voretaq7 Nov 15 '11 at 19:57
@CalvinFroedge Not even close. You're asking some incredibly rudimentary questions. I suggest that you read some documentation regarding RADIUS, 802.1x, and basic networking standards in general. – MDMarra Nov 15 '11 at 20:02
up vote 7 down vote accepted

You're Doing It Wrong.

You should get a proper switch that supports 802.1X authentication and configure that. It does exactly what you're asking for.

Now, as for "log the activity of each machine", you need to actually define that. Do you:

  • want to record each Ethernet packet that traverses the wire?
  • want to keep track of which CIFS files are opened?
  • want to record each website that is accessed?
  • want to record each TCP connection that's made?
share|improve this answer
Which CIFS files are opened, which websites are opened, which TCP connections are made. – Calvin Froedge Nov 15 '11 at 20:05
@CalvinFroedge How many machines do you want to monitor every TCP connection on? You're going to need some serious storage if it's any more than a few. – MDMarra Nov 15 '11 at 20:09
And a bloody switch is never going to keep track of CIFS filenames or which websites are opened. The first is better done by the server, with auditing. The second is better done at or near the gateway, by a proxy or passive snooping device. And recording each TCP connection is a deeply silly thing. Can you explain why you'd need that? – mfinni Nov 15 '11 at 20:13
@MarkM I just tweeted to you. I'd love to pay you for an hour of your time on the phone to help me get up to speed just a bit. – Calvin Froedge Nov 15 '11 at 20:15
@mfinni I don't expect the switch to keep track of any of this, I expect the server to do these sorts of things. Someone told me I couldn't connect via RADIUS with an 802.3x switch. If you will notice, my original question was simply How do I authenticate to my server via radius from my macbook, with the switch sitting in between.. For TCP connections, only connections made to / from outside the network. – Calvin Froedge Nov 15 '11 at 20:18

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