Network Configuration

To start this process we'll need to know the MAC address of a computer, what IP address it should be, and what host name that is. MAC is fixed in hardware, but the other two we'll have to decide.

In order to be able to network-boot the lab computers we need to use some of the existing department network infrastructure.

• DHCP - This provides three key services

  • assigns an IP address to a computer when it boots

  • additionally, we specify that a certain MAC address is always given the same IP address

  • tells the booting computer to contact a TFTP server for a boot image (PXELINUX which bootstraps a Linux kernel, in our case)

• DNS - Since the computer will always have the same IP address, we can map that to a human-readable name

DNS

Config file lives on ns1 (and ns2) at ns1:/usr/local/named.d/227.addrs This file is kept under version control and so, before editing, check it out

[cwilson@ns1 named.d]$ co -l 227.addrs
RCS/227.addrs,v  -->  227.addrs
revision 1.23 (locked)
done

Edit with your favorite editor and then check it back in

[cwilson@ns1 named.d]$ emacs -nw 227.addrs
[cwilson@ns1 named.d]$ ci -u 227.addrs
RCS/227.addrs,v  <--  227.addrs
<something>
done

These files are the input to a script that actually generates the BIND config

[cwilson@ns1 named.d]$ make update
[cwilson@ns1 named.d]$ make notify

be sure to check that DNS is up after this

DHCP

Config file lives at noc:/etc/instr-dhcpd.conf a typical entry for a lab computer looks like:

1. host fzx32541 {
2.         hardware ethernet B8:AC:6F:1C:0D:06;
3.         fixed-address 128.104.227.81;
4.         next-server 128.104.227.245;
5.         filename "pxelinux.0";
6. }

Line 1) refers to the host by its DNS name 2) names the computer by its physical MAC address 3) assigns this computer a fixed IP address 4) tells the computer the IP address of the TFTP server to contact 5) tells the computer what file to fetch from the TFTP server.

TFTP

This runs on DRBL. Make sure that there is a pxelinux.0 file at the root of the TFTP server.

CategoryComputing