Networking
- How I check an IP address without overtrusting geolocation
An IP lookup can show useful network context, but it does not prove a person’s exact physical location. The IP & Geolocation Lookup tool helps me inspect the input and output without writing a one-off script …
- How I check common port numbers when debugging a service
Port numbers are labels for network services, but a port number alone does not guarantee what is actually running there. The Port Reference tool helps me inspect the input and output without writing a one-off script …
- How I expand and read IPv6 addresses without guessing
IPv6 addresses can be compressed, which is convenient for typing but sometimes confusing when comparing or documenting them. The IPv6 Expander tool helps me inspect the input and output without writing a one-off script …
- How I generate MAC addresses for tests without colliding with real devices
Generated MAC addresses are useful for examples, tests, lab configs, and mock network data. The MAC Address Generator tool helps me inspect the input and output without writing a one-off script first.
- How I look up a MAC address vendor from the first bytes
A MAC vendor lookup uses the first part of a MAC address to identify the organization that registered that prefix. The MAC Address Lookup tool helps me inspect the input and output without writing a one-off script first.
- How I plan a small IPv4 subnet without doing binary math in my head
A subnet is a range of IP addresses. CIDR notation like 192.168.1.0/24 describes the size of that range. The IPv4 Subnet Calculator tool gives me a safe place to test the idea before I put it into a script, server, or …
- How I think about SSH tunnels before copying the command
SSH tunnels are powerful, but the flags are not friendly at first sight: ssh -L 8080:localhost:80 user@example.com The command is short, but the meaning is not obvious. Which machine is localhost?
- How I turn an IPv4 range into CIDR blocks
Many firewalls and cloud tools want CIDR blocks, but humans often receive IP ranges with a start and end address. The IPv4 Range Expander tool helps me inspect the input and output without writing a one-off script first.
- How I use DNS lookup when a domain does not work
DNS is the phonebook layer that turns names into records such as IP addresses, mail servers, and verification TXT values. The DNS Lookup tool gives me a safe place to test the idea before I put it into a script, server, …