Converting AIX dhcpsd.conf to Lnx pattern dhcpd.conf

Stewart Dean sdean at
Mon Feb 7 20:08:25 UTC 2011

I am converting a legacy AIX DHCP service (which I created and have been running 
for yea 10 years or so) to Linux (CentOS 5.5).  I have an AIX 2300 line legacy 
config file which, while vaguely of the same faith as the Linux version, is 
definitely a different denomination.  I throw myself on the mercy of those 
experienced in Linux DHCP.
I would dork around with a sample config file to figure out syntax questions, 
but all of the sample/prototype DHCP config files on the install (I looked with 
a find / -name "*dhcp*" -ls) fail when trying to start DHCP.  Yes, there are 
syslog messages, and I've been around and around to no avail trying to patch 
something up that wouldn't cause DHCP to barf.  So.......

#1: Would someone suggest a URL to a barebones, 30-50 lines or less, dhcpd.conf 
file that will successfully start so I can play with the syntax

#2 I see in Linux
subnet ww.xx.yy.zz netmask {
My old AIX syntax is:
subnet ww.xx.yy.zz
I can squirt in the netmask word, but does the open curly brace have to be on 
the same line or can it be on the next (as I currently have in on AIX)?

#3 In AIX, all the clients with declared addresses are called out either:
= withing the subnet definition envelope with a line like this:
client 1 <hex MAC address> ww.xx.yy.zz
  and with ww.xx.yy.zz falling within a range statement like this:
(of course in Linux, I have to remove the dash)
If there is a hostname defined, then the declaration goes *outside* the subnet 
envelope like this:
subnet ww.xx.yy.zz netmask
stuff, including a range statement that includes ww.xx.yy.zz
client 1 <hex MAC address> ww.xx.yy.zz
option 12 hostnamewombat

I am thoroughly confused by the docs, so I'll ask some kind soul to give me a 
sample declare with and without a hostname linking a MAC to a specific dotted 
quad IP in the range, but some questions on some details....
= must the MAC address have colons in it or can it be done as a long hex string 
(as in AIX)?.
= must the ethernet keyword always be there or is it optional

Laocoon should be the patron saint of system administrators, re: that wonderful 


"One must think like a hero to behave like a merely decent human being." - May Sarton
"Having overcome your worst fear, the thing you are most vulnerable to, that is the definition of heroic.
Also, it's such a worthwhile human activity. The most." -Fran Liebowitz

Funny how it's women who see the real heroism (that of going on, of being true) so clearly.
Stewart Dean, Unix System Admin, Bard College, New York 12504 sdean at
voice: 845-758-7475, fax: 845-758-7035

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