The way the renew button works in System Preferences is to create a key in the system configuration. One can create the key via:.
Currently, I'm doing the following for the wireless interface, but I'm wondering if there's a better way: Matthew Rankin Matthew Rankin 5 14 This can also be achieved with the following two commands: Rob's answer will certainly work - but ipconfig set always first de-configures the interface before setting up DHCP again. Interesting, I had figured this hint out already, but hadn't actually thought about what was happening when I turned the airport connection off.
That should accomplish the same thing. I also use the location "Automatic" in the Networking panel and have had no problems going seamlessly between my home Airport, my workplace wired Ethernet, or my workplace Airport All I've ever seen is instructions like the above: It's a way to prevent random people from connecting to your service.
The DHCP Client Identifier is just that, a unique per subnet identifier such as a hostname or serial number allowing the server to identify the client and select the appropriate response. In the absence of a Client Identifier, the "chaddr" field hardware address is used. Unless the server has specific per client configuration it barely matters which you use.
HOME and others use this because it's easier for them to restrict who can get an IP address by using a fixed per client id than by forcing customers to accurately provide them a 12 hex digit Ethernet address and change it everytime they change computers or interfaces cards. The use in logging is secondary, and primarily for network troubleshooting.
A client specified field isn't a very good choice for auditing and security purposes. Changing the client id or entering junk willy-nilly is bad for two reasons: This can result in duplicate IP addresses, which is a major headache for you too , defeating one of the biggest benefits of DHCP. For more information, please see RFC That's interesting.
How does uplugging your etheret cable renew your DHCP lease? In my experience it doesn't unless you unplug it for a looooong time, depending on the DHCP server's settings: I see I just unplugged my ethernet while looking at system.
Well, looks like OsX behaves a lot better than win95 or winNT in that respect. On NT you'd have to be admin to forcibly renew your lease. If this is a regular problem, creating a new location may be the best way. If you just need to do it once in a while, but don't want to create a location, switch to configure manually, apply, back to DHCP, and apply again.
Does this actually send a "release" to the DHCP server or simply shut down the interface locally? The following comments are owned by whoever posted them.
This site is not responsible for what they say. How I do it Authored by: Garvey on Feb 12, '03 Probably missing something Authored by: Spencerian on Feb 12, '03 A bit Authored by: How about ifconfig instead? Kip on Feb 12, '03 This is the way most pros do it on other Unix flavors.
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I have done ifconfig down followed by ipconfig DHCP. In any combination, the result is the same: I have tried unplugging the cable modem, letting time pass, then plugging it back in. Same problem. Even if I have an active lease, attempting to renew it by any of the above methods results in no IPv4 inet address.
The only thing that has worked is to set a cron job to shutdown -r the machine every 12 or 24 hours. Needless to say, this is completely stupid and highly disruptive, but nothing else has worked. I am at the end of my rope.
macos - Release/renew IP address via Terminal in OS X - Super User
Any ideas at all? Are you referring to the new Airport Extreme N here? Good luck, Ryan [ Reply to This ]. Thanks for the comment, Tony.
How Mac OS X Works
MacTipster on Jan 04, '12 MacTipster on Jan 20, '12 It is possible to do it with Mac OS X BiL Castine on Jan 22, '12 Search Advanced. From our Sponsor Latest Mountain Lion Hints Click here for complete coverage of Lion on Macworld. User Functions Username: What's New: