About VXLAN From Wikipedia: Virtual eXtensible LAN (VXLAN) is a network virtualization technology that uses a VLAN-like encapsulation technique to encapsulate OSI layer 2 Ethernet frames within layer 4 UDP datagrams, using 4789 as the default IANA-assigned destination UDP port number, although many implementations that predate the IANA assignment use port 8472. VXLAN attempts to […]
I, for one, was quite excited when IKEA announced new Matter-based affordable smart home devices in 2025. I finally got to buy some of them and I was going to add them in my existing Home Assistant system. Specifically, for this test, I bought: They are talking with each other using Matter over Thread, the […]
I’ve recently used various kinds of message queues when building various apps that have needs to communicate with other parts of the app. For remote use, when the messaging parties are not on the same host, I’ve mostly used Amazon SQS, the Simple Queue Service. When using the SQS ReceiveMessage API call you can select […]
I have made occasional contributions to the Wireshark project for over five years now. I started with small documentation updates, and later I have added two new protocol dissectors (Zabbix and Z21) as well as improved some other dissectors. It can be several months between contributions though, so this post is my own memo about […]
One of the new features in Zabbix 7.0 LTS is proxy load balancing. As the documentation says: Proxy load balancing allows monitoring hosts by a proxy group with automated distribution of hosts between proxies and high proxy availability. If one proxy from the proxy group goes offline, its hosts will be immediately distributed among other […]
One of the built-in security features in Zabbix is TLS (Transport Layer Security) support for external connections. This means that when your distributed Zabbix proxies or Zabbix agents connect to the Zabbix server (or vice versa), TLS can be used to encrypt all the connections. When the connections are encrypted, third parties cannot read the […]
A user has a Zabbix agent that collects the used disk space information on a host. The item interval is one minute: However, the user complains that Zabbix fails to collect to data appropriately as the graph has empty areas with occasional dots: In Zabbix implementations with very high NVPS (new values per second) this […]
As https://learn.microsoft.com/en-us/windows-server/networking/technologies/pktmon/pktmon puts it: Packet Monitor (Pktmon) is an in-box, cross-component network diagnostics tool for Windows. It can be used for packet capture, packet drop detection, packet filtering and counting. Nice thing about it is that it is present by default on all modern Windows versions, so you can do a quick packet capture when […]
One of the features of Zabbix proxy is that it can buffer the collected monitoring data if connectivity to Zabbix server is lost. In this post I will show it happening, using packet capture, or packet analysis. Zabbix setup and capturing Zabbix proxy traffic This is the setup in this demo: For simplicity, the agent […]
Let’s see how the Zabbix active agent autoregistration works in the communication. I have configured the Zabbix agent (version 6.2.3) on the Linux host at 192.168.7.17 with this configuration: ServerActive=192.168.7.15 Hostname=Test-agent After restarting the agent, the Zabbix server (version 6.2.3) at 192.168.7.15 logged immediately in /var/log/zabbix/zabbix_server.log: cannot send list of active checks to “192.168.7.17”: host […]