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dhcpd.conf configuration and internet access

Hello,
I have a ubuntu machine with two NICs. This has internet access through one NIC. The other is connected to a switch to which other machines connect. I have set up this machine to be a dhcp server and serve out local IPs to the connecting clients. I have successfully done this so that any machine connecting up to the switch gets an IP address (e.g. 192.168.0.2). This allows the client to connect to the host. However, these clients can not get on to the internet. In other words, they are limited to communication with the machines on a LAN. I presume that I have not the written the dhcpd.conf properly.

Here is my dhcpd.conf on the host

Code:

ddns-update-style none;



default-lease-time 259200;

max-lease-time 5184000;



# If this DHCP server is the official DHCP server for the local

# network, the authoritative directive should be uncommented.

authoritative;

option routers 192.168.0.1;



subnet 192.168.0.0 netmask 255.255.255.0 {

  group {

  host amfortas{

        hardware ethernet 00:1d:60:e2:61:1a; 

        fixed-address 192.168.0.2;

  }

  host lohengrin{

        hardware ethernet 00:1F:D0:21:3C:66;

        fixed-address 192.168.0.3;

  }

  }

}

and here is /etc/network/interfaces on lohengrin (a client)

Code:

auto lo eth0

iface lo inet loopback

iface eth0 inet dhcp

As I said, lohengrin can get an IP and can then ssh to and from the host. However, if I try to do something like "ssh 82.71.38.83" from lohengrin it does nothing (no errors messages, just hangs there until I control+c it), while I can successfully ssh into 82.71.38.83 from the host machine.

I presume there is something small that I am stupidly missing. Can anyone see what I have done wrong and how I could fix it?

-mark

We can get more information if you post the output of ifconfig of one of the dhcp-clients.

Markus

Dear Markus,

Thanks for your offer of help. I don't have any command called "ifconf":

Code:

andrews@ssh.lohengrin ~> ifconf

-bash: ifconf: command not found

andrews@ssh.lohengrin ~> sudo ifconf

sudo: ifconf: command not found

but I have "ifconfig" and here is the output from "lohengrin"

Code:

andrews@ssh.lohengrin ~> ifconfig 

eth0      Link encap:Ethernet  HWaddr 00:1f:d0:21:3c:66  

          inet addr:192.168.0.3  Bcast:192.168.0.255  Mask:255.255.255.0

          inet6 addr: fe80::21f:d0ff:fe21:3c66/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:421774 errors:0 dropped:25396230342 overruns:0 frame:0

          TX packets:334552 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000 

          RX bytes:156199763 (148.9 MB)  TX bytes:62962480 (60.0 MB)

          Interrupt:249 Base address:0x4000 



lo        Link encap:Local Loopback  

          inet addr:127.0.0.1  Mask:255.0.0.0

          inet6 addr: ::1/128 Scope:Host

          UP LOOPBACK RUNNING  MTU:16436  Metric:1

          RX packets:11700 errors:0 dropped:0 overruns:0 frame:0

          TX packets:11700 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0 

          RX bytes:807420 (788.4 KB)  TX bytes:807420 (788.4 KB)

For comparison, here is "ifconfig" on wotan (the dhcp server and host):

Code:

andrews@ssh.wotan ~> ifconfig

eth0      Link encap:Ethernet  HWaddr 00:16:e6:dd:ae:0c  

          inet addr:192.168.0.1  Bcast:192.168.0.255  Mask:255.255.255.0

          inet6 addr: fe80::216:e6ff:fedd:ae0c/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:336452 errors:0 dropped:0 overruns:0 frame:0

          TX packets:259489 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000 

          RX bytes:22030669 (21.0 MB)  TX bytes:922941417 (880.1 MB)

          Interrupt:16 



eth1      Link encap:Ethernet  HWaddr 00:18:4d:ea:77:52  

          inet addr:128.40.26.160  Bcast:128.40.26.255  Mask:255.255.255.0

          inet6 addr: fe80::218:4dff:feea:7752/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:20344104 errors:0 dropped:0 overruns:0 frame:0

          TX packets:12455605 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000 

          RX bytes:3975717650 (3.7 GB)  TX bytes:15290659227 (14.2 GB)

          Interrupt:19 Base address:0x4000 



lo        Link encap:Local Loopback  

          inet addr:127.0.0.1  Mask:255.0.0.0

          inet6 addr: ::1/128 Scope:Host

          UP LOOPBACK RUNNING  MTU:16436  Metric:1

          RX packets:6369 errors:0 dropped:0 overruns:0 frame:0

          TX packets:6369 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0 

          RX bytes:504066 (492.2 KB)  TX bytes:504066 (492.2 KB)

Sorry, I meant ifconfig (as you stated).

I did still not understand how exactly your connection to the internet should work. If It is a ppp-connection there would b a 32bit mask (255.255.255.255) for eth1 on wotan. but I don't know.

Since the connection between the computers on your local lan works there dhcp should be properly.

What about the routes (between the two nics), what I mean is that this machine with the two nics should function as a router.

Markus

Markus,
Thanks for the reply again.
From what you said, it may be that the dhcp server config is not the issue, but rather I do not have the host set up properly to route between the two NICs. That makes sense, and I will look into it.
-m