One DHCP server - two interfaces - two subnets

Similar Threads:

1.ISC DHCP - Two subnets on one physical interface.

I'm having some trouble trying to get dhcp to serve two subnets on one
interface.
The first is 10.0.0.0/24 which is for office workstations and
equipment.  Everyone in here is assigned a static ip via mac address.
The second is a 'guest' network which is 10.0.10.0/24.

I was able to get dhcp to assign the ip address for both subnets by
making the subnet declaration 10.0.0.0/16.  The problem is that there
are other settings that need to be set like the default route, dns,
netmask, etc.

In my first attempt, I made a pool and set all the settings to be that
of the guest network.  I would then override those settings in the
host declarations for the office equipment.  The problem is that it
didn't like having options such as routers,domain-name-servers, etc in
the host declarations.

Does anyone know how I can do this without a second NIC?

Below is my current config.
################ Current Config #################
max-lease-time 86400;
default-lease-time 14400;
ddns-update-style interim;

log-facility local4;

subnet 10.0.0.0 netmask 255.255.0.0 {
        authoratative;
        range 10.0.10.10 10.0.10.250; ## Guest Network

        # don't let clients update A records for ddns
        ignore client-updates;

        # options
        option subnet-mask 255.255.255.0;
        option broadcast-address 10.0.0.255;

        option domain-name "domain.tld";
        #option domain-name-servers 65.106.1.196,65.106.7.196;
        #option routers 10.0.10.1;
        option domain-name-servers 10.0.0.225;
        option routers 10.0.0.1;

        option ntp-servers 10.0.0.250;

        option netbios-scope "";
        option netbios-node-type 8;

host ws1 {hardware ethernet 00:13:21:d0:3f:0b;fixed-address 10.0.0.3;}
host ws2 {hardware ethernet 00:0d:9d:4c:94:4d;fixed-address 10.0.0.5;}
host ws3 {hardware ethernet 00:0d:9d:4b:35:bd;fixed-address 10.0.0.6;}
host ws4 {hardware ethernet 00:0b:cd:c3:ee:03;fixed-address 10.0.0.7;}
}
########################################

The following is what I would have liked to set up.  Understandably
the following won't work because the two networks are not physically
separated, and there is only one NIC available for dhcp.


max-lease-time 86400;
default-lease-time 14400;
ddns-update-style interim;

log-facility local4;

subnet 10.0.10.0 netmask 255.255.255.0 {
        authoratative;
        range 10.0.10.10 10.0.10.250; ## Guest Network

        # don't let clients update A records for ddns
        ignore client-updates;

        # options
        option subnet-mask 255.255.255.0;
        option broadcast-address 10.0.10.255;

        option domain-name "guest.domain.tld";
        option domain-name-servers 65.106.1.196,65.106.7.196;
        option routers 10.0.10.1;
}


subnet 10.0.0.0 netmask 255.255.255.0 {
        authoratative;

        # don't let clients update A records for ddns
        ignore client-updates;

        # options
        option subnet-mask 255.255.255.0;
        option broadcast-address 10.0.0.255;

        option domain-name "domain.tld";
        option domain-name-servers 10.0.0.225;
        option routers 10.0.0.1;

        option ntp-servers 10.0.0.250;

        option netbios-scope "";
        option netbios-node-type 8;

host ws1 {hardware ethernet 00:13:21:d0:3f:0b;fixed-address 10.0.0.3;}
host ws2 {hardware ethernet 00:0d:9d:4c:94:4d;fixed-address 10.0.0.5;}
host ws3 {hardware ethernet 00:0d:9d:4b:35:bd;fixed-address 10.0.0.6;}
host ws4 {hardware ethernet 00:0b:cd:c3:ee:03;fixed-address 10.0.0.7;}
}

2.Two subnets on one interface with no VLANs

Hi,

I'm looking for input from anyone that has experience of running two
subnets on one inteface.

Eg:

172.16.1.1/24 and 10.10.10.1/24 both bound to one NIC via a layer 2
switch without using VLANs.

Will it cause problems ? I can't find much online that's concrete.

I'd appreciate any help,

JR

3.One graphic card, two monitors, two X servers?

Hi,

We have a system with a Matrox Millenium G550 graphics card which has
two monitor adapters. I can set them up using xinerama or two displayx
:0.0 and :0.1. This is not exactly what I want.

Is it possible to run two instances of the X server on the same card,
each one serves one monitor?

- Monitor A should become display :0.0 and show xdm and normal window
manager for a user
- Monitor B should become display :1.0 and only show a full screen X
application and not be affected what happens on monitor A.

One idea was to run a X server on both monitors and then use Xnest for
the window manager session on monitor A, but I cannot get xdm running
in Xnest.

Thanks for any hints.

Regards,
Bernd

4.Solved: One graphic card, two monitors, two X servers

Hi Jon,

> That implies the X server inherits is keyboard from the tty device its
> started from. See "vtXX" in "X --help"
> You can tie it down with the Keyboard section of the X config file.
>
> If thats not it then its getting a little two involved for me to follow
> second hand !
>
> Which linux distro is it ?

Thanks for that hint. It's SUSE LINUX Enterprise Server 9 SP3. The
solution was to give X the same arguments as shown in
/etc/X11/xdm/Xservers. Now the X server also has keyboard input when
started at system boot.  I'll recall the whole solution for future
googlers with the same problem.


(1) Use GDM and start it in the background without occupying the
screen. Example of /etc/init.d/gdm:

/opt/gnome/bin/gdm --no-console &

(2) Enable remote access with GDM in /etc/opt/gnome/gdm/gdm.conf:

[xdmcp]
Enable=True
HonorIndirect=true

(3) Start up X server in /etc/inittab so it will be restarted when
terminating it with Ctrl+Alt+Backspace:

x:5:respawn:/usr/X11R6/bin/xinit /etc/X11/xinit/xinitrc.my --
/usr/X11R6/bin/X -nolisten tcp -br vt7

(4) The /etc/X11/xinit/xinitrc.my starts the two Xnest on each screen,
one with the application and the second with the GDM login screen.

==CUT==
PATH="/sbin:/usr/sbin:/bin:/usr/bin:/usr/X11R6/bin:/opt/gnome/bin:/usr/local/bin"

# Touchscreen
Xnest -display :0.1 -ac -geometry 1280x1024+0+0 -xkbmap
'xfree86(de_CH)' :2 &
export DISPLAY=:2.0
su nobody -c "/usr/X11R6/bin/xclock -geometry 1280x1024+0+0" &

# Console Screen
while true; do
  export DISPLAY=:1.0
  Xnest -display :0.0 -ac -geometry 1280x1024+0+0 -xkbmap
'xfree86(de_CH)' -query localhost :1
done
==CUT==

Hope next one will find the solution faster than me. ;-)

Bye
Bernd

5.Forwarding of multicast packets between two subnets with two NICS - Does not work

WHY DO I NOT GET ANY REPLY FROM A DIFFERENT SUBNET? WHY ARENT
IGMP/MULTICAST PACKETS BEING FORWARDED THROUGH THE LINUX BOX?

Here is my setup:

                               Linux Box with two NICS
PC1         router          NIC(eth0)---NIC(eth1)          router
 PC2
192.168.1.100 192.168.1.1 192.168.1.111 192.168.4.114 192.168.4.1
192.168.4.100


Linux Box:
---------
/proc/sys/net/ipv4/ip_forward


PC1
----
ping 192.168.4.1 - works
ping 224.0.0.1 - only get reply from 192.168.1.1 and 192.168.1.111


PC2
----
ping 192.168.4.1 - works
ping 224.0.0.1 - only get reply from 192.168.4.1 and 192.168.1.114

WHY DO I NOT GET ANY REPLY FROM A DIFFERENT SUBNET? WHY ARENT
IGMP/MULTICAST PACKETS BEING FORWARDED THROUGH THE LINUX BOX?

6. How to handle two networks - one DHCP, one fixed IP

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