forcing new dynamic ip address

[Ernie Luzar]

Mike wrote:
> On 10/8/2017 8:28 AM, Ernie Luzar wrote:
>> Hello List;
>>
>> I have a "home service" account from my ISP. The ISP issues an dynamic 
>> ip address which has not changed in 12 years.
>>
>> My host has 2 NICs, one which is not used. I know if I plug the internet 
>> cable into the un-used NIC and make the appropriate config changes and 
>> reboot I will get a different dynamic ip address.
>>
>> Is there a simpler way to expire the lease to force the ISP dhcp to 
>> refresh with a different dynamic ip address?
>>
>> The goal is to have a cron job that gets a different dynamic ip address 
>> assigned to my host's front door every a week.
>>
>> Just another level of security to make it very hard for the script 
>> kiddies from finding any open ports I may have.
>>
>> Thanks for the help.
> 
> 
> I have a few old NICs that i keep, not because I need to use them, but
> because i want to be able to use their MAC address.
> 
> Then I use one of the MAC addresses in rc.conf, e.g.,
> 
> ifconfig_em0="DHCP lladdr yo:ur:MA:C:ad:dr:es"
> 
> My ISP assigns a new IP address when the DHCP server sees a new MAC address.
> 
>

Thank you. This is the solution I was looking for. I tested it and it 
works. But I have to first cycle the cable modem's power off/on to 
signal the isp network that new hardware is being used and prepare to do 
  dhcp function.