Networking

Multicast DNS (mDNS) is a networking protocol designed to resolve hostnames to IP addresses within small networks, without the need for a local DNS server. It requires no configuration (zero-configuration) and uses the same programming interfaces, packet formats and operational semantics as unicast Domain Name System (DNS). It was designed to work as either a standalone protocol or alongside standard DNS servers. mDNS can work together with DNS Service Discovery (DNS-SD), a complementary zero-configuration networking technique specified separately in RFC 6763. …

A couple of months ago I moved the DHCP and DNS services to my home Linux router and left the Pi-Hole 5 service on a separate virtual machine. Despite everything working perfectly, I hit a snag: troubleshooting from PiHole is complicated because all DNS queries are resolved by the router and PiHole sees nothing. So I decided to redesign the setup. In this post I describe how I install Pi-Hole 6 on my Linux router so it provides DNS, DHCP (with dnsmasq) and ad sinkholing. This involves undoing the native dnsmasq installation. …

In this post I describe how I’ve evolved my home DHCP and DNS server. Until now I had a PiHole dedicated on the network to DHCP, DNS and ad sinkhole. I’ve decided to migrate to a different configuration, move both DNS and DHCP services to the home router (Linux). I realized that when PiHole went down, the rest of the home services would spiral out of control, despite having the router and internet working, so I’m leaving PiHole exclusively as the ad sinkhole. …

I’m sharing my home networking setup with the option to knock on the door for on-demand access from the Internet. Today’s home networks end up supporting multiple services, and with the rise of home automation things get complicated, so I’ve decided to document it to keep track of everything in the future. The number of devices grows and maintaining the network of a smart and automated home becomes a priority. I dedicate this post to those Geeks or Techies who, like me, have been deep into the complexity of networking in a home automation network for a long time. …

In this post I explain how I launch a network traffic capture (tcpdump) on a remote Linux machine (Pi2 with Gentoo) and have it forwarded to Wireshark running on my computer (Mac). We’ll get tcpdump’s output to become Wireshark’s input. It seems like magic but you’ll see it’s extremely simple. You’ll need to know ssh and sudo, a couple of prerequisites for making this so easy. …

Not long ago I came across PeakHour, a tool that lives in the macOS menu bar with a very pleasant look & feel, capable of visualizing your home network traffic in real time. To achieve this it uses the SNMP protocol — you register all devices that support the protocol and it polls them sequentially, displaying the traffic passing through them. …