How To: Resolve Multicast DNS (mDNS) using Dig in Linux
Sometimes it can be nice to verify that the hostname on your box (printer, raspberry pi, whatever) is resolving to the correct IP-address on the LAN. Whether it’s published via Avahi, Bonjour or something similar. An mDNS request resolves to. IPv4 address 224.0.0.251 or IPv6 address ff02::fb UDP port 5353 This can be achieved with…
How To: Redirect HTTP Traffic to Proxy Using iptables
Proxy Madness Using Squid or any other proxy for transparent caching/filtering of HTTP traffic has many benefits, being for logging purposes or the aforementioned use-cases, keeping every client configured can be a nuance. Networking equipment from Cisco and Juniper has the ability to redirect all passing HTTP traffic, in IOS and JunOS respectively, to the…
How To: Netcat – Check for open ports with the command line
Kitty Port-checking When troubleshooting a network integration or any other connection issue in Linux, step one is usually a matter of checking to see if the network port on the other side is even responding. Netcat -The network Swiss Army knife (Hobbit, not nmap)- is the right tool for the job. Before we begin, NetCat…
How To: Encrypt/Decrypt File with OpenSSL
Encrypt/Decrypt File When security and integrity of a file is critical, such as with x509 certificates or other important documents, OpenSSL or other variant can be used to secure the file. With strong encryption and -hopefully- a strong password. OpenSSL is generally available on all UNIX variants, downloadable as an executable for Windows and is…