DHCP failover to static IP addr

I am configuring a Fedora Core2 Test2 system.
I would like to activate eth0 using dhcp, but if that fails (no dhcp server
on the network) I would like to assign a static IP address.

One approach is using dhclient and creating an /etc/dhclient.conf file:

send host-name "home.test";
send dhcp-client-identifier "home";
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, host-name;
timeout 30;
retry 60;
reboot 10;
select-timeout 5;
initial-interval 2;

lease {
interface "eth0";
option host-name "home.test";
fixed-address 10.1.1.1;
renew 1 2004/10/25 22:24:33;
rebind 2 2004/10/26 04:00:03;
expire 2 2004/10/26 05:30:03;
option subnet-mask 255.255.255.0;
option broadcast-address 10.1.1.255;
option domain-name "test";
}

This functions normally when a DHCP server is present on the net, but when
there is no server, 'ifup eth0' tries 10.1.1.1 but fails. It fails during a
verification process for 10.1.1.1 resulting in bash dumping its environment
variables and the contents of
/etc/sysconfig/network-scripts/network-functions. It then displays a usage
message for ping... eth0 remains down.

Does anyone know if this is a proper use for the fixed-address parameter of
a lease in the dhclient.conf file?

If this doesn't work, I guess I could just write a script that checks if the
interface is up after initial network startup. If not, it can configure the
interface with a static IP address.

Any suggestions?
Thanks in advance

On Mon, 25 Oct 2004 15:53:16 -0700, Bob Williams wrote:

> I am configuring a Fedora Core2 Test2 system. I would like to activate
> eth0 using dhcp, but if that fails (no dhcp server on the network) I
> would like to assign a static IP address.
[..]
> If this doesn't work, I guess I could just write a script that checks if
> the interface is up after initial network startup. If not, it can
> configure the interface with a static IP address.
>
> Any suggestions?

Not sure if this will do what you are looking for...:

man dhclient-script:
"After all processing has completed, /sbin/dhclient-script checks for
the presence of an executable /etc/dhclient-exit-hooks script, which if
present is invoked using the '.' command."

AFAIK, a /etc/dhclient-exit-hooks script can be used to set the desired
default static IP address...

http://chrismetcalf.net/wiki/index.p...sForLinuxHacks
http://zeroconf.sourceforge.net/

--
mvh/regards
Joachim Mæland

If everything seems under control, you're just not going fast enough.
-Mario Andretti

Bob Williams wrote:
> I am configuring a Fedora Core2 Test2 system.
> I would like to activate eth0 using dhcp, but if that fails (no dhcp server
> on the network) I would like to assign a static IP address.
>
> One approach is using dhclient and creating an /etc/dhclient.conf file:
>
> send host-name "home.test";
> send dhcp-client-identifier "home";
> request subnet-mask, broadcast-address, time-offset, routers,
> domain-name, domain-name-servers, host-name;
> timeout 30;
> retry 60;
> reboot 10;
> select-timeout 5;
> initial-interval 2;
>
> lease {
> interface "eth0";
> option host-name "home.test";
> fixed-address 10.1.1.1;
> renew 1 2004/10/25 22:24:33;
> rebind 2 2004/10/26 04:00:03;
> expire 2 2004/10/26 05:30:03;
> option subnet-mask 255.255.255.0;
> option broadcast-address 10.1.1.255;
> option domain-name "test";
> }
>
> This functions normally when a DHCP server is present on the net, but when
> there is no server, 'ifup eth0' tries 10.1.1.1 but fails. It fails during a
> verification process for 10.1.1.1 resulting in bash dumping its environment
> variables and the contents of
> /etc/sysconfig/network-scripts/network-functions. It then displays a usage
> message for ping... eth0 remains down.
>
> Does anyone know if this is a proper use for the fixed-address parameter of
> a lease in the dhclient.conf file?
>
> If this doesn't work, I guess I could just write a script that checks if the
> interface is up after initial network startup. If not, it can configure the
> interface with a static IP address.
>
> Any suggestions?
> Thanks in advance
>
>

Any reason why you cant have 2 IP addresses on eth0, one static and one
DHCP?

--
Respectfully,


CL Gilbert

"Verily, verily, I say unto you, He that entereth not by the door() into
the sheepfold{}, but climbeth up some other *way, the same is a thief
and a robber." John 10:1

GnuPG Key Fingerprint:
82A6 8893 C2A1 F64E A9AD 19AE 55B2 4CD7 80D2 0A2D

For a free Java interface to Freechess.org see
http://www.rigidsoftware.com/Chess/chess.html