dns suffix search list

[Nathan Spear]

Before I brought up two new domain controllers and removed the two old
domain controllers my cleints had 3 suffixes listed in their ipconfig
/all output.

I have read all over the web that this can not be done by the DHCP
server, but I think that is not true. I recall a conversation that
adding an option 119 to the DHCP sever serves this purpose, however it
no longer works.

My question is how did my network have these 3 domain suffixes served
up? What other services or devices could do it? How is this done is
a hetrogenous environment (windows and linux)? (the solution can't be
group policy since linux hosts don't listen to that)

I found a post about option 135 but haven't found more info to lead me
down that path. Perhaps there is another DHCP option I can use.

thanks for your thoughts.

Nathan Spear
Network Administrator
iovation, Inc.
(e-mail address removed)

 

[Guest]

AFAIK, option 119 is not available in W2K DHCP.

This KB might be helpful to you.

How to Configure a Domain Suffix Search List on the Domain Name System Clients
http://support.microsoft.com/default.aspx?scid=275553

BR,
Denis

 

[Lee]

Well, it seems it must be done using a registry script of some sort in
Windows 200x
http://support.microsoft.com/default.aspx?scid=kb;en-us;275553
http://www.microsoft.com/technet/itsolutions/network/deploy/depovg/tcpip2k.mspx#EDAA

I guess you'd have to write a startup script using the ifconfig cmd, I'm not
a Linux guy so a Solaris command is close as I'm going get.

I too read a lot about a RFC for dhcp assigning the dns searchlist but I
haven't found any way MS in implementing it. In all my projects, the list
was assigned during the image creation, an unattended install script or
brute force with a gang of techs visiting each desktop.

Please post your final results because this IS a thorny issue!

Lee

 

[Lee]

I just found something by accident. If DHCP is issuing the domain name AND
append primary and connection specific dns suffixes is selected in the NIC
properties AND connection specific dns is set it has the effect of adding
two domains to the dns searchlist. The connection specific domain and the
dhcp domain issued are merged to create the searchlist. I guess this is how
your clients had dual domains in the searchlist.

Lee

 

[Nathan Spear]

Lee,

My solution is to use group policy for the Windows clients and we will
have to edit resolve.conf on the linux workstations.

-Nathan

 

[Nathan Spear]

Looks like I don't have a solution yet. Using the Group Policy works
great for the Windows clients. Problem is with the Linux clients
every time a machine gets a new lease the resolve.conf gets clobbered,
requiring the user to edit the file again to add the proper dns
suffixes.

Does anyone know a way around this? Is there a way to prevent a
Microsoft DHCP server from overwriting a Linux resolve.conf file?

-Nathan

 

[Nathan Spear]

Let me try and ask this question again, in a different way.

Currently my Microsoft DHCP server is overwriting the resolv.conf file
on the Linux hosts, but with only one dns suffix, not the three my
environment requires.

Here is the desired resov.conf;
[root@lt-dpc1 etc]# more resolv.conf
; generated by /sbin/dhclient-script
search foo.bar.com next.domain.com another.domain.com
nameserver 192.168.12.60
nameserver 192.168.12.62

Here is what the DHCP server is writing to the Linux clients;
[root@lt-dpc1 etc]# more resolv.conf
; generated by /sbin/dhclient-script
search foo.bar.com
nameserver 192.168.12.60
nameserver 192.168.12.62

Does anyone know how to pass the right search string to the Linux host
with a Microsoft DHCP server (Windows Server 2003)?

-Nathan

 

[Kevin D. Goodknecht Sr. [MVP]]

In

Let me try and ask this question again, in a different
way.

Currently my Microsoft DHCP server is overwriting the
resolv.conf file on the Linux hosts, but with only one
dns suffix, not the three my environment requires.

Here is the desired resov.conf;
[root@lt-dpc1 etc]# more resolv.conf
; generated by /sbin/dhclient-script
search foo.bar.com next.domain.com another.domain.com
nameserver 192.168.12.60
nameserver 192.168.12.62

Here is what the DHCP server is writing to the Linux
clients; [root@lt-dpc1 etc]# more resolv.conf
; generated by /sbin/dhclient-script
search foo.bar.com
nameserver 192.168.12.60
nameserver 192.168.12.62

Does anyone know how to pass the right search string to
the Linux host with a Microsoft DHCP server (Windows
Server 2003)?

-Nathan

DNS suffix search list are not included in Microsoft DCHP, currently MS DHCP
can only publish a Connection DNS suffix which is added to the DNS Suffix
search list.

 

[Jonathan de Boyne Pollard]

Currently my Microsoft DHCP server is overwriting the resolv.conf file on the Linux hosts,



False.  The DHCP clients on your Linuxen are overwriting the resolv.conf files on those machines.  Understand that, and the rest will follow.