Moving a UNIX box to the gigabit network

The migration to gigabit requires the modification of two aspects of server configuration. Networking parameters have to be changed, and the configuration of the campus time service (based upon NTP, the network time protocol) will be changed. The specific steps to reconfigure your server depends on your particular flavor of Unix. The details are outlined below for the variants UCNS currently supports. For any other UNIX OS contact WSG and we will help.

Note: this document assumes you are migrating from a class B network setup with a 16-bit network mask (255.255.0.0) to a class C network with a 24-bit network mask (255.255.255.0). Our usual setup with a 24-bit network mask is a network with a base address of 128.192.subnet.0 and a gateway of 128.192.subnet.1. In some cases (such as a building with very few clients) we may assign a network with different parameters. In such a case, substitute the network parameters the NOC gives you for the netmask, base address and gateway when making your changes.

Irix:
  1. Create an /etc/config/ifconfig-1.options that contains the line:


    2. netmask 255.255.255.0

    (This assumes that you have one network device. Details may vary. Check /etc/init.d/network for more details.

  2. Edit /etc/init.d/network.local to change your default gateway from 128.192.1.1 to 128.192.subnet.1 in two places (where subnet is the third number in your machine's IP address):
    3.     case "$1" in
     'start')
    
    #Default route
    
    /usr/etc/route add default 128.192.subnet.1 1
    
    lines omitted... 
    
     'stop')
    /usr/etc/route delete net default 128.192.subnet.1
  3. Create an /etc/ntp.conf file with the following contents: 
        server time1.uga.edu
    server time2.uga.edu
    fudge 127.127.1.0 stratum 100
    If this file exists and contains any lines refering to "broadcastclient" delete them or comment them out. Changing the stratum for localhost to 100 means the local hardware clock will only be used as a backup.


  4. Then restart the network and xntpd, or reboot.

Solaris

 Edit three files:


  2. In /etc/netmasks make sure you have the following:


  3. 128.192.subnet.0   255.255.255.0
  4. In /etc/defaultrouter make sure the following is present:


  5. 128.192.subnet.1

    where subnet is the third number in your machine's IP address.

  6. In /etc/inet/ntp.conf include the following:


  7. server time1.uga.edu
    server time2.uga.edu
    fudge 127.127.1.0 stratum 100

    If this file exists and contains any lines referring to "broadcastclient" delete them or comment them out. Note: changing the stratum for localhost to 100 means the local hardware clock will only be used as a backup.

  8. Now restart networking or reboot the box.
You can try "/etc/init.d/networking stop; /etc/init.d/networking start" from the system's console. (You have to use the console because you might lose your connection if you're logged in remotely.) You can use "ifconfig -a" to see whether the new parameters have taken effect. The output should now contain "netmask 0xffffff00" instead of "netmask 0xffff0000".

Do "netstat -rn" and check the "default" line. It should look like "default 128.192.subnet.1".

If you don't see the desired results, you may as well reboot the box. This will force the new parameters to take effect.

Note: in the worst case, you can use the "sys-unconfig" command. This will tell your box to forget who it is and to shut down. When you boot it back up, it'll ask "who am I?", "what's my IP address?", etc., similarly to an initial install.

Linux

  1. Edit the file /etc/ntp.conf to include the following:


  2. server time1.uga.edu
    server time2.uga.edu
    fudge 127.127.1.0 stratum 100

    If this file exists and contains any lines referring to "broadcastclient" delete them or comment them out. Note: changing the stratum for localhost to 100 means the local hardware clock will only be used as a backup.

  3. Edit the file /etc/sysconfig/network and make sure it has a gateway line:


  4. GATEWAY=128.192.subnet.1

    (Note: Replace subnet with the subnet YOU are using.)

  5. Edit the file /etc/sysconfig/network-scripts/ifcfg-eth0 (or what-ever network device you are using) and make sure it has the following lines:


  6. DEVICE=eth0
    BOOTPROTO=static
    BROADCAST=128.192.subnet.255
    IPADDR=128.192.subnet.your IP
    NETMASK=255.255.255.0
    NETWORK=128.192.subnet.0
    ONBOOT=yes

    (Note: Replace subnet and your IP with the subnet and IP YOU are using.)

  7. If this box has been on the network before it may already have entries for the campus nameservers, but it can't hurt to check. Edit the file /etc/resolv.conf and make sure it has the following lines:


  8. nameserver 128.192.1.9
    nameserver 128.192.1.193
    nameserver 168.24.242.249

  9. Stop and restart the network by running:


  10. /etc/rc.d/init.d/network restart

    You can check on network settings by running:

    /sbin/ifconfig -a

AIX
  1. type "smitty tcpip"
  2. select "Minimum Configuration & Startup"
  3. select "Standard Ethernet Network Interface" (probably "en0")
  4. set "Network MASK" to "255.255.255.0"
  5. set "Default GATEWAY Address" to "128.192.subnet.1", where subnetis the third dot-separated number in your machine's IP address
  6. set "START TCP/IP daemons Now" to "yes"
  7. hit Enter
Last modified: Tuesday, 13-Nov-2001 11:42:43 EST
URL: http://www.uga.edu/ucns/wsg/move2gig.html