Category Archives: Linux

Discoveries and adventures in Linux, computers, and networking

Quick Tip: rsync –exclude-from syntax

The rsync –exclude-from option specifies a file that contains exclude patterns (one per line). It is very picky about the way the pathname is entered. It appears to be a path relative to the current directory. The only option that worked was “–exclude-from=./filename“. A full path from the root directory didn’t work, nor did a… Read More »

Quick Tip: DNS and resolved configuration with OpenVPN

After climbing the steep learning curve to get OpenVPN to work on Ubuntu (as a client), I ended up with a VPN that worked but still had issues with DNS name resolution. What finally worked for me was to use the distribution defaults for everything, but install libnss-resolve and openvpn-systemd-resolved packages. This worked for a… Read More »

Network Booting with DNSMASQ in Proxy Mode

In this project, I will show you how to network boot an Arch Linux ISO image with DNSMASQ set up in proxy DHCP mode. The approach taken here should readily generalize to the ISO images of other distributions. If you understand what’s being done here, adapting to another distribution should not be too difficult. I’m indebted to… Read More »

Amazon Web Services S3 via Command Line

Amazon Web Services (AWS) has a nice Command Line Interface, allowing script or command line access to quite a wide range of capabilities. I recently attempted to use this with the Simple Storage Service (S3), but was frustrated with a repeated error message in response to a simple directory request on a bucket. jeff@mars:~$aws s3… Read More »

Fixing VSFTPD login problem

I recently set up a new Ubuntu 12.04 server, and as part of the setup installed vsftp. I used an identical setup to a similar server, but for some reason, I kept getting an authentication error attempting to login as a local user. After a lot of troubleshooting, I finally isolated the problem to the… Read More »

Faster IPSET loading

IPSETs are a very efficient way to manage a large list of IP addresses for your iptables firewall. Rather than have an individual rule for each and every address or network that needs to be dropped or rejected, with ipsets you can have a single iptables rule that tests an entire list of addresses. The rule… Read More »

Botnet Attack

As has been extensively publicized elsewhere, a very large scale botnet has been organized to attack sites using WordPress. This site has the dubious honor to have been included this last weekend. The attack attempts to log in to the site using the user name “admin” or a number of variants on that name, then… Read More »

DD-WRT Update

It’s been over two years since I initially posted about all the <a title="Fun With DD-WRT" href="https://www losartan potassium 50 mg.n0dy.com/2011/01/fun-with-dd-wrt/”>fun I was having with DD-WRT and my Linksys WRT-600N wireless router. I thought it might be time to revisit the DD-WRT site and see if there have been any software updates since my last… Read More »

ISP Research

My son, Michael, and I generally get along pretty well. We share the household and keep out of each other’s way for the most part. Conflict does arise, though, when we’re both on the internet at the same time. He’ll be on YouTube and I’ll be trying to download some files. Or he’ll be gaming… Read More »

Using a Router with Verizon DSL

You’d think that something as commonplace as using a wireless router with your DSL connection would be very straightforward and easy these day. Well, it actually isn’t too hard, but you have to be aware of some things that Verizon tech support doesn’t seem to clue you in to. As usual, first let me tell you about the pain I suffered along the way. If you’re not interested in that, you can just skip down to the “Getting It to Work” section