Red Hat Bugzilla – Bug 108429
/sbin/ifup executes dhclient with -1, so that it quits when dhcps is down
Last modified: 2014-03-16 22:39:58 EDT
Description of problem:
If the DHCP server is not accessible when dhclient is trying to renew the
lease, dhclient quits, so your interface loses its IP address. You have to ifup
Steps to Reproduce:
1. Set up a short lease time on the server. Ifup on the client.
2. Disconnect the dhcp server from the client.
3. Notice that dhclient quits when the lease expires, and it can't renew.
I have had to rescue quite a few systems because of this issue(fedora
core 1 has the same problem). Not everyone has the time to keep tabs
on all the firewall systems they deploy to bring the network up when
dhclient quits because the lease expires.
It would be nice to have a -2 option for dhclient that causes dhclient
to fail if it first can not get a lease, but once it does get that
first IP it will always attempt to even on expire.
That way network scripts get the feedback they need(pass or fail) and
users get what they need( an interface that never gives up trying to
get an IP once it acquires one initially).
I wonder what the chances are of getting ISC to accept a patch for
that? I am rather suprised nobody else has done that yet.
Current releases have support for a PERSISTENT_DHCLIENT; this may solve your needs.