This list was created when I physically moved my FreeBSD server from a lower-speed connection to a high-speed data center co-location service. The assumption is that the box will be locked in a closet once configured, accessible only via the Intenet/ssh.

Don't forget to to have your upstream provider update the reverse DNS name of your IP address! If you're on a DSL or some such, by default this name probably indicates that you are a dialup, which will be blocked by many mail servers.

A few days before making the move:

• edit /etc/namedb/<your-machine-hosts-file> and lower TTL, expire, and refresh values to a few hours.
  Obviously if you have multiple domains, you'll have to do them all. (If you don't already, this is sure to get you to convert to using common files which do include.)

• Edit /etc/resolv.conf with new DNS server(s).
  (Of course the first line in the file will still be: domain=<your-domain-name>
If you're running your own DNS/BIND server, you should have yourself listed first:
nameserver=<your-server-ip> Followed by the DNS server supplied by your upstream provider:
nameserver=<upstream-provider-server-ip>
• Edit /etc/rc.conf with new gateway:
  Your upstream provider will supply you with the ip address of their gateway (amy also be called router) for your system: defaultrouter=ip-of-upstream-gateway
  You'll already have turned on your gateway with:
  gateway_enable="YES".
• You'll change the new IP address in the ifconfig:
  ifconfig_<device=inet <your-new-ip>
  (I'm omitting other possible options in the ifconfig -- that's your problem.)
• Hopefully your ISP is forwarding the old IP address to the new for you, in which case you'll enter the old as an alias:
  ifconfig_lo0_alias0="inet <your-ol-ip>.
  (Again, I'm omitting other options in the ifconfig line.)
• Edit /etc/rc.firewall with new onet and oip.
• Reboot
• You may need to get things working using manual ifconfig commands.
• Keep at it until if you can ping somebody in the outside world (or in some way prove that the network is working).
• From some external machine, make sure you can do an ssh inbound.
• Make sure to update /etc/rc.conf with the final ifconfig.
  Once done, reboot machine so as to make sure you can still get out and in if you were to have to do a remote reboot.

• Edit /etc/namedb/<your-system-hosts-file>. (Obviously this must be done for all domains on the box) and restart named.
• Check /etc/mail/<your-systems.mc>. Also check access file, regenerate cf file and restart sendmail if changed.
• Edit /usr/local/etc/apache/httpd.conf and restart apache. (All virtual domains.)
• Edit /usr/local/etc/smb.conf and restart dhcp.
• cd /usr/local/etc and grep <old-addr> * adding /* layers until you've checked all files6.
• Go to your domain name registrar(s) and update them.
• Go to dnsreport.com to check your work.
• Don't forget to go to your DNS and mail secondarying machines and go through the same list of files on each.
• Don't forget to go to inform anyone else who depends on your IP of the change; for example are you subscribed to RBL+ at mail-abuse.org?. Do you have anyone doing secondarying for you?

• Go back to dnsreport to ensure that all is still as you think it is.
• Set time values in dns settings back to more reasonable values, like those recommended by dnsreport.