[Sunhelp] Enabling DHCP?

[Flynn, Harold M. III]

Speaking of which, there's an issue with the DHCP server that comes with the
addon packs for the SunRay setup (don't ask me which one off the top of my
head...I'll research it if you don't know and need the info).

This is, of course, from my preliminary research.  I haven't had a good
chance to really scrub on this.

The problem is with the initialization script /etc/init.d/dhcp.  When a
machine with 2 interfaces is placed on 2 seperate networks (On with the
sunrays, and one production network), problems can occur.

While the dhcp server is running, it answers internal dhcp requests for the
sunray servers, giving them their boot information and bringing them up.
Unfortunately, dhcp is promiscuous on both interfaces of the machine, and
while listening for and answering the packets on the sunray network, will
also attempt to answer dhcp queries on the other interface.

Here is a synopsis of the two networks:

rrrrrrrrrrrrrrrrrrrr	rrrrrrrrrrrrrrrrrrrrrrrrr
rrrr sunray rrrr	rrrrrrr sunray rrrrrr
rrrrrrrrrrrrrrrrrrrr	rrrrrrrrrrrrrrrrrrrrrrrrr
         |                          |
         |                          |
         |                          |
          \                        /
            \                    /
              \                /
               oooooooooo
               oo   Intel  oo
               oo  Hub   oo   100BT
               oooooooooo
                      |
                      |------------------------------------- Network A
  192.168.1.1   |       hme0
        sssssssssssssssss
        sssss   Ultra2    sss
        sssssssssssssssss
                      |          le0
                      |-------------------------------------Network B
   Vaild IP        |


As you can see, there's a private network, then a valid network.  DHCP
answers requests for both networks A and B.

Solution:

Alter the /etc/init.d/dhcp script to force dhcp to listen on only one
interface.  Here's the variable from the script...it's written in KSH:

# SUNRAY DEL DHCPDOPTIONS=""
DHCPDOPTIONS=""
ulimit -n 1024 # SUNRAY ADD

The interface listening option is not configurable via the menu driven dhcp
config.  Using network A for example, to get the server to listen on the
interface hme0, add an entry such as the following:

# SUNRAY DEL DHCPDOPTIONS=""
DHCPDOPTIONS="-i hme0"
ulimit -n 1024 # SUNRAY ADD

Cheers,
Hal

> -----Original Message-----
> From:	Robert Brady [SMTP:Robert.Brady at central.sun.com]
> Sent:	Thursday, April 13, 2000 12:45 PM
> To:	sunhelp at sunhelp.org
> Subject:	Re: [Sunhelp] Enabling DHCP?
> 
> The DHCP server is included in SunOS 5.6.  I believe that the question was
> how 
> to enable the SPARC to use the dorms DHCP server.  If that is correct,
> take a 
> look at ifconfig(1M).  The last two examples under SYNOPSIS cover the use
> of 
> DHCP.  A basic config would be `ifconfig le0 dhcp start`.  This will
> configure 
> the interface until it is stopped or the system is rebooted.  If you want
> to 
> configure DHCP to acquire an address each time the system is booted,
> that's a 
> bit more complex.  Take a look at info doc 16207 named "How to setup a
> DHCP 
> client" on http://sunsolve.sun.com/  it goes through the steps in great
> detail.
> 
> 
> Hope this helps.
> 
> -=-r
> 
> The opinions contained in this email are in no way related to the opinions
> of 
> Sun Microsystems.  
> --------------------------------------------------------------------------
> -----
>         
>         
>         
> From: "Han, SangBeom" <sbhan at os.korea.ac.kr>
> To: <sunhelp at sunhelp.org>
> Subject: Re: [Sunhelp] Enabling DHCP?
> Date: Fri, 14 Apr 2000 00:39:08 +0900
> charset="ks_c_5601-1987"
> Reply-To: sunhelp at sunhelp.org
> 
> -----BEGIN PGP SIGNED MESSAGE-----
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> 
> As I know, DHCP server included in Solaris 2.6 has a bug. However,
> the patch is available for contracted user.
> 
> - --
> OOOOOOOpen Mind!
> OOOOOOO
> OO   OO  sbhan at os.korea.ac.kr, handdol at nownuri.net
> OO   OO  http://home.nownuri.net/~handdol
> OO   OO  Operating System Lab. in Korea University
> OO   OO  (lab) 02-3290-3573    (private) 017-282-8968
> OOOOOOO
> OOOOOOOpen World!
> # Everything is illusion.
> # From Kring, the Fantasy World.
> - ----- Original Message -----
> From: "Paul Khoury" <pkhoury3 at earthlink.net>
> To: "SunHELP List" <sunhelp at sunhelp.org>; "SunRescue List"
> <rescue at sunhelp.org>
> Sent: 2000 4 13   6:30
> Subject: [Sunhelp] Enabling DHCP?
> 
> 
> > How do I enable DHCP on my SPARC (Sol2.6)?
> >
> > I'm using my SPARC now in a friends' dorm room, but their T3 is
> > DHCP, so I can't get it to route.
> > And changing the subnet mask doesn't seem to help either - any
> > suggestions?
> >
> >
> >
> > _______________________________________________
> > SunHELP maillist  -  SunHELP at sunhelp.org
> > http://www.sunhelp.org/mailman/listinfo/sunhelp
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