One of my old laptop is my home server, openSuse 12.1 console based, and everything is good on that when I connect it to the wired network. but when I try to connect through the Wireless I found that “dhclient” is missing. Here are the steps I performed
“dhclient” should be in “/sbin”. Perhaps you have a broken path for root.
According to my checking, it comes in the “dhcp-client” rpm, and I’m pretty sure that is installed by default.
I’m not quite sure what you are doing there. The normal default is to use “dhcpcd” for connections configured via Yast, and “dhclient” for connections configured with “NetworkManager”.
It’s possible that you are tripping over some of the effects of the switch to “systemd”. Maybe try with “sysvinit” and see if that changes anything.
To illustrate: I am using “sendmail” for email. If I want to restart “sendmail”, the tradition method is to send it a SIGHUP signal.
That seems to not work any more, presumably due to systemd interference. The logs show that it worked, but a subsequent check shows that sendmail is not running. I have to restart it a different way (running the script in “/etc/init.d” does work).
While on this issue, be warned of a bug in “dhclient”. See Bug 732910 for details. The workaround is to turn on dhcp debugging, which you can do with Yast → System → /etc/sysconfig → network → dhcp