dhclient starts on startup, but no IP is configured

Glenn Satchell Glenn.Satchell at uniq.com.au
Mon Aug 14 13:38:39 UTC 2006

>Date: Mon, 14 Aug 2006 08:13:45 -0500
>From: "Isaac Grover" <isaac.grover at gmail.com>
>To: dhcp-users at isc.org
>Subject: dhclient starts on startup, but no IP is configured
>Good morning from Wisconsin,
>I am running FreeBSD 6.1-RELEASE with four NICs: rl0, rl1, dc0 and
>sis0.  All the *0 NICs are static IPs, and rl1 is the only NIC that
>gets its IP through DHCP.  At the moment, there is nothing else
>running on this box except ssh and no firewall is configured yet.
>On boot, dhclient starts up to get an IP for rl1 via DHCP, but there's
>an error and I see the dump of what looks like a README, but it
>scrolls by too quick to catch it all.  After logging in, doing an
>'ifconfig rl1' never shows an IP for rl1.  Minutes can go by; still no
>IP.  So I do a 'killall dhclient; /sbin/dhclient rl1' and I have an IP
>for rl1 within seconds.
>Has anyone here seen this behavior before?
>Thank you in advance,
>Isaac Grover, Owner

Hi Isaac,

Some switches take a while for a port to be active after the link is
detected. In the meantime dhclient times out. So when you manually run
dhclient after the system has booted, the switch port is now active and
communication happens.

If you search to archives for terms such as "portfast" I think you'll
find how to disable this on, at least, Cisco switches. Alternatively
you may be able to bump up the timeout in dhclient.conf.


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