Unable to Qualify My Own Domain Name

Today a network engineer called me and said that he needed a file that was supposedly residing on a decommissioned ftp server.

Wonderful.

I spent my morning digging through the pile of yet-to-be-surplussed hardware and found what I think might be the correct machine. Yet another 280R being revived and pressed into service. (Incidentally, 280R's are heavy, do not lift it by yourself as you will probably hurt your back or tear your pants, or both.) Turns out my first pick was the wrong machine. Somebody conveniently removed the machine labels when they went to the surplus pile. My second, equally heavy, pick is the correct machine.

So, I wrangle the beast into place and plug everything in and power it up, I also have a laptop plugged into the RSC card because I know better than to think it will boot happily. Turns out, though, that I'm wrong. It boots up quite nicely, and immediately begins to complain about not being able to qualify it's name:

unable to qualify my own domain name (servername) -- using short name

Now, when a Solaris machine throws that error, you can be sure that nothing to do with the network will function. This error is caused because the machine cannot find its DNS server on the network. That could mean that the DNS server is gone or, more likely, that the network is not configured properly.

Since I know that this machine was in a different building before it was decommissioned, I imagine that the jack it is plugged into is not correctly set up to support the network configuration on the server. To find out what the machine expects, I try an ifconfig -a:

prompt $> ifconfig -a

lo0: flags=2001000849
inet 127.0.0.1 netmask ff000000
eri0: flags=1000843
& inet xxx.xxx.69.99 netmask ffff0000 broadcast xxx.xxx.69.127

Welp, I wasn't root when I ran that command, so the MAC address is not showing. Network engineers ALWAYS want the MAC address so they can trace the machine through the network. So, I'll have to try again as root:


prompt #> ifconfig -a

lo0: flags=2001000849
inet 127.0.0.1 netmask ff000000
eri0: flags=1000843
inet xxx.xxx.69.99 netmask ffff0000 broadcast xxx.xxx.69.255
ether 0:3:ba:xx:xx:xx

OK, we see the IP address and the MAC address. Good. Be aware that the MAC does not display proceeding zeros. Some network engineers will not understand that format. I always relay it like this:

00:03:BA:XX:XX:XX

The other thing I notice is the dreaded interface type. Experience tells me that 'eri0' does not cooperate well with Cisco switches that auto-detect speed settings. So I pass this info along to the engineer who sets up my port correctly and sets the speed to run at 100Mb.

Still doesn't work.

After some arguing with the engineer, I find that the network is set up to use a small CIDR block. That leads me to look at the ifconfig -a output again:

eri0: flags=1000843
inet xxx.xxx.69.99 netmask ffff0000 broadcast xxx.xxx.69.255
ether 0:3:ba:xx:xx:xx

That netmask value, 'ffff0000' looks a lot like a Class B address, so does the broadcast address. I check with the engineer. Sure enough, they are wrong. He tells me the correct netmask and the correct broadcast address. Now I need to set those values. Ifconfig is, again, your friend:

ifconfig eri0 netmask 255.255.255.192 broadcast xxx.xxx.69.127

Now we check to see if it took:

prompt #> ifconfig -a
lo0: flags=2001000849
inet 127.0.0.1 netmask ff000000
eri0: flags=1000843
inet xxx.xxx.69.99 netmask ffffffc0 broadcast xxx.xxx.69.127
ether 0:3:ba:xx:xx:xx

Huzzah! But does the network actually function?

prompt #>nslookup yahoo.com

Server: xxx.xxx.67.1
Address: xxx.xxx.67.1#53

Non-authoritative answer:
Name: yahoo.com
Address: 66.94.234.13
Name: yahoo.com
Address: 216.109.112.135

I call the engineer back and give him the login/password info he needs, and he gets his file! Finally, I can turn the beast off and move it out of my office. It was starting to get hot. As an additional precaution, I take the time to make a copy of the file in question on my PC, so that I won't have to play this game again in 6 months time.