December 18, 2018 Update

This month, our “hobby” server took a big dump, and we said, “screw it, we need to install the ‘new’ server.” This “new” server is a few years old, but switching servers is such a huge pain in the ass that we avoided it.

Besides, the old server has been pretty reliable. We’ve had to replace the power supply, a hard drive, and memory, but… not bad for 10+ years. Fsck even fixed it up, but re-racking a heavy 2RU, decade+ year old server is a terrible idea.

I’ve got three new articles, and the first two are from this upgrade:

One new page is an aggregation of a series from a while back about fixing my personal computer:

  • The Crashing Computer Series – Long notes about how I diagnosed and fixed my crashing personal computer (it was RAM). Don’t do what I did.

I’ll try to share one article I’ve read that’s tech/internet in each post.

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Debian and Ubuntu Networking Configuration /etc/network/interfaces with a Static IP Address

This is easy to find anywhere, and it’s here too. This one includes the dns-* lines that will be read by resolvconf(8).

root@server:/etc/network# cat interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
address 192.168.1.251
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
gateway 192.168.1.254
dns-nameservers 192.168.1.250
dns-search mydomain.local

Also, here’s a cheatsheet for setting that netmask:

255.255.255.252  /30    2  nodes
255.255.255.248  /29    6  nodes
255.255.255.240  /28   14  nodes
255.255.255.224  /27   30  nodes
255.255.255.192  /26   62  nodes
255.255.255.128  /25  126  nodes
255.255.255.0    /24 "Class C" 254 nodes

Note that the number of nodes is the total number of addresses, less two. It’s less two because the lowest value is the address of the entire network. The highest value is the broadcast address. So if the netmask is 0, then the lowest value is 0, and that’s the address of the network, and the highest value is 255, which is the broadcast address.