How to force DHCP client router to renew its lease?

Question

Hi,

I have a Cisco 2514 acting as an Internet gateway in a CCNA study lab setup. I have a Comcast cable modem connect to e1. The 2514 is configured as a DHCP client to get its IP addressing info from Comcast. This all works fine.

Occasionally when I change configurations in the lab I want to force the 2514 to renew its DHCP lease info from Comcast. The only way I have been able to do this is to power cycle the cable modem. Then "shutdown", "no shutdown" interface e1. Simply shutting down the interface and bringing it back up does not cause the router to get a fresh IP address on e1 unless I power cycle the modem first.

Is there a better way to do this? It seems to that there would be a direct unambiguous command to renew the DHCP client, something akin to "ipconfig /renew" in windows. But, I'm new to this and may not be thinking in the correct context.

Thanks, John

Martin Bilgrav · Accepted Answer

IOS router, you can go into conf-t mode under the interface and simply re-issue the "ip address dhcp command" This will then, as it is in running config, get excecuted at once.

Try it, and give a yell, if its ok or not.

HTH Martin Bilgrav

JohnH. · Answer

Thanks, that did it.  i copied the "ip address DHCP..." command intothe clipboard, entered "no ip address."  I then pasted the ip addressdhcp command back from the clipboard hit enter and a new IP address wasrecieved from the ISP right away.

Martin Bilgrav · Answer

no need to say "no ip address" first, just simply re-issue the "ip addressdhcp"HTHMartin

JohnH. · Answer

Thanks for the tip!

How to force DHCP client router to renew its lease?

Join the Discussion

Didn't find your answer?