Tag Archives: dhcp

Perfect DHCP configuration for Solaris

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I've already posted on configuring DHCP + Dynamic DNS for some operating systems.

I still claim that that's the only way to go for dynamic, trusted networks.

So after RedHat, Debian/Ubuntu, Windows, it's about time to stop the IP suffering with Solaris as well:

  1. Make sure /etc/nodename contains the FQDN, e.g. "snoopy.ac.uk"
  2. touch /etc/dhcp.<interface name> . There are two peculiar parameters I'm not fully sure about their meaning (how come they're not needed in other OSes?) - but here is what I used:
    1. add "primary" (a separate line) if it's the primary interface.
    2. Add "wait <seconds>" (a separate line) - I put "wait 60" to be on the safe side.
  3. /etc/hostname.<interface name> should have the hostname inside. NOTE! It's the hostname dhcp client would send (Option 12) to the server for Dynamic DNS registration. According to /etc/defaults/dhcpagent, the format is "inet name", e.g. "inet snoopy"

That should be it, then. Please add your comments and corrections.

Make DHCP auto-update the DNS

8 Replies

Update: added a new post on configuring Solaris, link below.

Motivation

In today's dynamic R&D network environments, it's not easy to keep the DNS records up-to-date: hosts are reinstalled/renamed/added frequently, virtual machines are so easy to deploy and destroy, DHCP allocates different IPs..

This even leads to pitiful situations, in which people get used to referring to computer by their IPs (or using /etc/hosts), because the DNS cannot be trusted to reflect the reality.

Solution

DHCP servers have the ability to send dynamic DNS updates, as they allocate IPs to clients. The great thing, is that it even works out-of-the-box on some operating systems. Still, if it doesn't, here are 3 things to care about, so to enable this feature: Continue reading →

Booting Linux from iSCSI

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What is this long post about?

iSCSI is standard for accessing block devices (e.g. disks) over network, just as if they were local SCSI devices. That's similar to AoE and FCoE, although the latter two are good for the LAN only, while iSCSI is over IP thus is good on WAN. This article would focus iSCSI but could be used as a base for doing similar things with AoE and FCoE.

So, iSCSI in the simplest configuration, allows us to mount and manage a data disk that is physically connected to a remote computer (the "server", aka target) from our own computer (client, aka initiator) .

On this post I'll discuss the deep details of the more advanced stage: having the root (also boot) disk on a remote computer, so client could remotely boot from it. Surprisingly it can be done even with relatively old hardware.

Continue reading →