Recent posts (paged)
As an IT professional it's quite common to have to connect to web servers with invalid certificates, for different reasons. For example, opening a management GUI of an appliance may be necessary to change its own certificate or TLS settings. Problem: sometimes Chrome won't let you open this website, and gives you no ...
Problem: In syslog you find a line like this: smartd[1514]: Device: /dev/sda [SAT], Failed SMART usage Attribute: 5 Reallocated_Sector_Ct. But when you check with "smartctl -a" you find a reallocated sector count of zero: # smartctl -a /dev/sda ... ID# ATTRIBUTE_NAME FLAG TYPE UPDATED WHEN_FAILED RAW_VALUE 5...
Problem: When pasting commands to the shell, the shell no longer executes the command but shows the pasted text highlighted and shows the line feed but does not process it. Discussion: Devuan4 and Debian11 upgraded the readline library with a new default "feature" that should prevent noobs from accidentally pasting...
Every Cisco switch has a serial number that shows information about its production location and year. SW# show version Cisco IOS Software, C3560 Software (C3560-IPBASE-M), Version 12.2(35)SE5, RELEASE SOFTWARE (fc1) Copyright (c) 1986-2007 by Cisco Systems, Inc. Compiled Thu 19-Jul-07 18:15 by nachen Image text-bas...
Some protocols need more than one TCP or UDP connection. For NAT to work the firewall needs to open additional ports to allow client-server connections automatically. Examples are FTP (port 21 handshake, additional ports for data), PPTP (port 1723 for handshake, proto GRE 47 for payload) Since Linux kernel (~) 4.7 th...
Problem: curl php wget and others show a cert error like the following since 6. Oct 2021, even though the cert has not expired: curl: (60) SSL certificate problem: certificate has expired More details here: https://curl.haxx.se/docs/sslcerts.html curl performs SSL certificate verification by default, using a "bundle...
Admins who prefer a Unix-style operating system and don't like the centralized "one tool doing it all" approach of systemd, switch to Devuan. This mostly improves uptime over boot time. Admins of servers don't care about boot time and prefer uptime. This list keeps track of the related versions of Devuan and Debian....
There are at least two pieces of software you can update in a Cisco ASR-1001-X. The ROMMON (firmware) and the IOS itself. This router uses "Cisco IOS XE Software", which is an IOS process on a Linux kernel as far as I know. Cisco recommends specific ROMMON releases for different generations of software. You can look...
DHCP relaying is used to forward DHCP requests to a DHCP server if the client and the server are not on the same network. One standard implementation of this is isc-dhcp-relay which is part of the isc-dhcp package. Problem: The dhcrelay is forwarding the dhcp request to the dhcp server and the dhcp server is respond...
After Devuan 3 update ls output showed characters that are not really in the directory listing. The reason is that "ls" draws quotes around filenames with spaces. This is a bug from my point of view, ls should never change the actual filenames. If a filename has quotes or double quotes it's even weirder. "ls" adds...