Migrating to Linux: Tip 1: Do DHCP and DNS first

6:16 pm General

If, like most organisations, your client PCs get their IP addresses and DNS and routing information over DHCP, you can make your migration life easier by moving your DHCP server first, followed by your local nameserver.

Whenever you need to declare a server name or IP address for a service (mail, time, proxy, whatever), use a service-specific domain name: smtp.mycompany.office, imap.mycompany.office, ntp.mycompany.office and so on.

Since you control the DNS server, you can incrementally move these over to your Linux server and you only have to change the IP address once, in your central nameserver, rather than do the rounds of all the clients every time you switch a service, allowing a painless incremental approach to moving basic internet services which, if you do things right, people won’t even notice.

Next: the hard stuff: Exchange and Outlook.

Edit: Update .local to .office – .local is reserved for mDNS (thanks to my readers for spotting this!)

8 Responses

  1. Tomasz Says:

    uh, change “.local” into “.example” before some thinks about using it for real. “.local” is reserved for mDNS.

  2. nona Says:

    Watch out with .local unicast dns, see:


  3. Sam Morris Says:

    You should not use ‘.office’ either. You risk conflicting with future Internet standards. You must use a real domain name that you control, or a domain name like ‘mshome.net’ that has been set aside by a third party for local network use.

  4. Jerome Haltom Says:

    How do you propose to do secure DDNS? Windows has all that stuff worked out. Linux does not. I don’t know why you’d discard a service for an inferior one.

  5. James Cape Says:


    You don’t let the clients pick their own hostnames, you assign them statically from DHCP using a host entry in dhcpd.conf and the ddns-hostname stanza. Or use a subdomain for your untrusted DDNS entries.

  6. Jerome Haltom Says:

    @James Cape:

    Sounds like extra work. I like to use software to make me do less work. Every time there’s a new machine I have to set up it’s entry in a hosts file? Boring.

  7. James Cape Says:


    I’m not going to play some silly psychological game with you.

  8. Peng’s links for Monday, 16 February « I’m Just an Avatar Says:

    […] Neary: Migrating to Linux: Tip 1: Do DHCP and DNS first. Moving your computer network to Linux isn’t as painless as we’d really like, but Dave […]