What have they done to my SLIP?

James Wilkinson jimmy at cs.cofc.edu
Sat Nov 19 00:46:36 GMT 2005

When I taught our networking course two and a half years ago we 
connected some of the machines in the lab using null modem cables on 
the serial ports and SLIP. The setup was dead trivial, and it worked 
the first time and every time. Most of the connections use Ethernet, 
but I thought that they should at least see an example of a 
point-to-point link.

I tried it again this fall using the same cables similar machines 
(Dell GX110) and had no success at all. We tried several of the 
cables connecting different pairs of machines and always got the same 
result: ifconfig would report that the IP addresses were in place; 
netstat would report that the routes were there;  ping would claim to 
be sending packets, but had 100% packet loss.

We installed the version of FreeBSD that was current at the time in 
both instances: 4.something back then and 5.4 this time. That's the 
only difference I can think of between then and now.

Setup was
	slattach -lchs 9600 /dev/ttyd0
	ifconfig sl0 inet netmask
That's all. Back then I think we did the ifconfig first. Now we have 
to do the slattach first to get the sl0 device to appear.

I've looked at ppp, but it seems much more complicated. I've found 
instructions for setting it up, but they all assume that it will be 
used with a modem to connect to an ISP. I've never found any any 
place that will tell me how to set it up using the null modem cables.

Can anybody tell me how to get something to work? I'd settle for 
either SLIP or PPP.

Jimmy Wilkinson            | Professor of Computer Science
jimmy at cs.CofC.edu          | The College of Charleston
(843) 953-8160             | Charleston      SC        29424

If there is one word to describe me, that word would have to be 
Any form of incompitence is an athema to me.
Metathesis??? Don't ax me.
Just between you and I, the grammar used by Americans are getting worse.
I can only help but wonder what the cause of this might be.
It just ceases to amaze me how it could be the case, but mostly I 
could care less.

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