On Tue, Aug 13, 2019 at 07:46:37AM -0400, Jerry Geis wrote:
Odd thing happened... A centos 7 install set for DHCP. boot the box no network connected. I let it like this overnight. I come in this morning and plug in the network. Is it supposed to get a DHCP address at that time ? It did not . service network restart did get an address.
if I unplug the network, reboot the box, want a minute or so - then plug the network in - it gets a DHCP address.
Is there a "limit" to the time that the OS will keep trying to get a DHCP address ?
The RFC for DHCP describes a randomized exponential backoff for retransmission. This means it'll wait longer and longer between retries.
However, when you unplug the network cable, on boot the 'network' service doesn't even try to bring up the interface. If you're using NetworkManager, it should detect the interface activating and bring up the interface. Perhaps you had turned off NetworkManager, but the reboot brought it back?