I am running slackware64-current and I have a Broadcom Corporation NetLink BCM57780 Gigabit Ethernet PCIe ethernet controller which uses the tg3 kernel module. I am using the default huge kernel. Firstly, the card isn't recognized with default settings, but inserting the following line into modprobe.conf fixes that: This allows ethernet to obtain a dhcp lease during the boot process, however, if I get disconnected or unplug the cable, I am no longer able to re-establish a connection.

I have tried:
dhclient eth0
dhcpcd eth0
/etc/rc.d/rc.inet1 restart

and all simply time out before obtaining an IP, and I have to reboot in order to get back online.

I have also tried running both init scripts (rc.S and rc.M) to no avail.

Not sure how to resolve this, but I am open to suggestions. Thanks.

You should be able to issue, as the root user:
ifconfig eth0 down

Check it to make sure:
ifconfig
and eth0 should be missing.

Then do this:
dhcpcd -N eth0 OR dhcpcd eth0
I use the -N because I don't like having my ntp server settings messed with. But you have to change Slackware's initialization scripts as well or this doesn't matter.

You can also do:
/etc/rc.d/rc.inet1 eth0_stop
and /etc/rc.d/rc.inet1 eth0_start
That should have the same effect as a reboot.

The issue turns out to be with the modules broadcom and tg3 and wicd.

The following appears to resolve the issue

modprobe -r broadcom
modprobe -r tg3
killall wicd
modprobe broadcom
modprobe tg3
/etc/rc.d/rc.inet1 restart
wicd

Yeah. I've always found Broadcom chipsets to be a real pain. Glad you got it working.