Interesting Behavior with Solaris 2.8

John Tabasz (jtabasz) jtabasz at
Fri Aug 14 19:46:02 UTC 2009

The /etc/ files are for the second interface's benefit. I'm only
configuring the dmfe0 interface with dhcp. The dmfe1 interface is
generally customized differently by the user. Also, I can't guarantee
that there is a dhcp server on the second interface. They're on 2
different subnets. 

The thing that gets me is that without waking up dhcpagent, the netmask
and IP pair on the second interface can be completely controlled by the
netmasks and hostname.dmfe1 files, even if they break rules of
subnetting. If I do invoke dhcpagent some strange set of rules apply
that don't adhere to subnet masking at all. For instance, with dhcpagent
controlling dmfe0, I can set the IP of dmfe1 to in
hostname.dmfe1 and /16 in /etc/netmasks and that's how the interface
gets configured. If I try to set the dmfe1 to with in /etc/netmasks, the interface cones up with a /24 mask.
AFAIK, is a totally legit address in the subnet. 

Thanks for the comments,


-----Original Message-----
From: dhcp-users-bounces at
[mailto:dhcp-users-bounces at] On Behalf Of Neff_Glen at
Sent: Friday, August 14, 2009 6:16 AM
To: dhcp-users at
Subject: RE: Interesting Behavior with Solaris 2.8

Many aspects of Solaris' IP stack have been a mystery to me, but why
would you be touching /etc/netmasks if you're using DHCP to configure
the interfaces?  The subnetmasks should be specified in your dhcpd

Also, are you sure this isn't old lease info cached in /etc/dhcp/dhc.*
on the solaris host?


 * Glen R. J. Neff
 * RTP TSG Lab Team
 * neff_glen at
 * EMC^2 == E^2

-----Original Message-----
From: dhcp-users-bounces at on behalf of John Tabasz
Sent: Thu 8/13/2009 7:48 PM
To: Users of ISC DHCP
Subject: Interesting Behavior with Solaris 2.8

I have a Sun V100 running Solaris 2.8. I want dmfe0 to be under the
control of the dhcpagent on Solaris and dmfe1 to be statically
Previous to running a DHCP server in this environment I had no problems
configuring the Sun the way I want them to be. 

My secondary interface, dmfe1 I want to be configured as with
the netmask of This is a legitimate combination of values.
I do the following in order to do this.
#cat /etc/netmasks

#cat /etc/hostname.dmfe1

Before I introduced dhcp to the environment, on booting, the server
would come up with the following interface configuration for dmfe1:

dmfe1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index
        inet netmask ffff0000 broadcast

This looks completely legitimate to me. is a legitimate address
in the subnet 

However, I introduced dhcpd into the environment and use it to deliver
address and dns and hostname information for the other interface only. 
On the client I run 
#echo primary > /etc/dhcp.dmfe0   to allow dhcpagent to control the
When the V100 comes up, even though the dhcpagent should have nothing to
do with the dmfe1 interface, dmfe1 gets configured such with the same
values in the /etc/netmasks and /etc/hostname.dmfe1 files:

dmfe1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index
        inet netmask ffffff00 broadcast

So for some reason the control of dmfe1 is bleeding over from dmfe0, and
it's behaving in a way that looks like it violates subnetmasking rules.

Can anyone comment on this? Do I need to upgrade my dhcpagent rev or

Thanks in Advance,

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