Re: [cobalt-users] Changing IP address of a RAQ 3

[elmer@xxxxxxxxxxxxxx]

On Mon, 12 Feb 2001, Tom Manos so wrote:

} I need to change the network the box lives on. Is the process
} really as simple as changing the box's IP address in the control
} under "network", then changing each virtual sites' IP address,
} then changing the DNS entries for each virtual site? DNS lives
} separately on another dedicated DNS server.

Hi Tom,

	It is indeed that simple however there are propogation
issues you need to deal with. If you just simply change the IP
addresses you'll be offline until the new information propogates out
over the Internet. Quite simply, when someone wants to view one of
the sites or the a page they'll be directed to the previous IP
addresses until the DNS servers that make the Internet work are
updated to reflect the changes.

	The safest way to do this is to have who ever is doing DNS
for you set the TTL on your domains to about a minute or so 24 hours
or more before you make the changes. Then make those changes in the
wee hours of the morning 1 or 2 AM your time.

	Cranking down the TTL will cause most (not all) name servers
to keep much more current records on your domains. Give it a day or
two by having the TTL changed before you make the changes. Then make
those changes during the lull in traffic so that as few visitors as
possible will be directed to the black hole you are going to create
by switching IP addresses.

	Your DNS provider should know exactly how to do this. If
not, get one that does as fast as you can :-)