Articles in Category "Administration"

Update July 16th 2020: A reader has pointed out to me that the regular expression did not (or did not always) match if the filename of the attachment contained non-ASCII characters, opening a simple way to circumvent this header check. I was able to reproduce this behavior by sending a mail with a single attachment […]

I would like to emulate a public DNS entry that does not exist yet, while i am developing the service that will use this name on an intranet server. Let a public domain name i develop the service for be myservice.my-cool-domain.biz. When working in my intranet 192.168.2.0/24, i want to override whatever public DNS resolves […]

In my intranet, where hosts are in a subnet 192.168.2.0/24 and domain names in a domain mydomain, I use BIND9 as DNS, running on host intradns.mydomain , and NGINX as a webserver running on intraweb.mydomain. I would like to rewrite all subdomains of certain public domains (spammers and trackers) using my intranet DNS to a […]

The package of xrdp (Version 6.1.2) that is available in Debian does lack support for Copy&Paste. The “master” branch of xrdp on github provides this feature but is not packaged for Debian at the moment. To have it available, I built it manually on my Debian server. The procedure took about 1 hour, most of […]

Today I rebooted an Ubuntu 14.10 that was set up with LVM and encryption. It was unable to use the encrypted swapspace cryptswap1, which ultimately halted the boot procedure with a prompt (S for skip and M for manual resolution, i.e. single-user-mode prompt). The problem appears to be that the UUID (blkid) of the designated […]

Introduction ICMP (Internet Control Message Protocol) in IPv6 is used for a variety of purposes. As opposed to IPv4, support for some of the applications of ICMP by nodes participating in an IPV6 network is mandatory. On the other hand, due to the security-relvant nature of some of the applications, where in IPv4 it may […]

Written as a Bourne Shell-Script that invokes a Perl one-liner: LC_ALL=C df -kPT | perl -ane ‘!/(^Filesystem|tmpfs)/ && do { printf(“%-33s: %s\n”, $F[0], “*” x int((`tput cols`-35) * $F[3] / $F[2])) }’