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What is the best time to set the IP address for a server? I have a server that I am going to install the OS on and then I am going to send it to a server colocation facility. The server is going to have Internet facing services (www, email, etc.) I can set up a "fake" IP address during install (by fake I mean private as in RFC 1918) and change the "fake" IPs to the real IPs once I set up the colocation service. The other option is to set up the colocation service...wait for them to give me the "real" IPs and use them during the OS install.

The ramification are that...if I use "fake" IPs during install...I will have to wait before I set up things like SSL certs. If I wait for IPs from the colocation provider...then I can set up SSL certs that use the "correct" (as in "real") IP changes to the certs until they expire.

Do the "gotchas" of changing an IP address on a server outweigh the benefits of a quick install? The other danger with using "fake" IPs is that I could make a mistake when I go through the various files to change the IP address to the "live" IP address.

Server OS: CentOS 6.2 or CentOS 6.3, 64 bit. Apps: Apache 2.4.X httpd, MySQL 5.X (will eventually use replication)

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Why are you using SSL certificates based on IPs rather than host names? – gparent Dec 14 '12 at 20:27
Also, there's no way you should make a mistake changing the IP address unless you already made the mistake of not documenting your setup and redoing it from scratch to be sure it works. – gparent Dec 14 '12 at 20:27
The big difference between me making this change when I worked for a company...and now...this is my baby. After being out of work for a while...and now starting my own company...I HAVE to be right! At this point I have no backup to my reasoning. This place is a "kind of backup SA" for me. Thank you for your input. I was going to put the certs in by host name...just making sure I am not missing anything. Thanks again! – jim_m_somewhere Dec 14 '12 at 20:38
up vote 3 down vote accepted

Sounds like only thing you'd need to change when you got the IP from the co-lo provider would be network config and /etc/hosts, and perhaps some apache config lines if you were using specific IPs in there rather than NameBasedVirtualHost entries. I have done these install and bulk setup in advance, then before I haul it to the co-lo, fire it up, edit those things and shutdown. YMMV.

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Agreed! Thank you for your input. Please see my comment above! – jim_m_somewhere Dec 14 '12 at 20:39

When deploying a server to a remote site, I tend to let it pick up an IP by DHCP, and set up a reservation for what I want it to be.

That way, if something goes wrong, it will be able to at least pick up some IP from DHCP, so I can remote into it and fix things, without having to try to walk some window-licker through changing the IP over the phone. And if things go right, it's already got the IP I want, and I can change it from DHCP-assigned to static wihtout much effort.

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