Tools
Cygwin packages a large set of open source Unix tools for Windows. These are the ones I reach for when a network problem needs diagnosing, plus a few that only run on Linux.
The table shows where each tool comes from on each platform: a Cygwin package on Windows, and a dnf or apt package on Fedora and Ubuntu. N/A in the Cygwin column means the tool is not packaged for Cygwin. Several of those have native Windows builds instead; each tool’s own page has the details.
Open Source Tools
| Command Line Tool | Cygwin Package | Fedora (dnf) | Ubuntu (apt) | Usage |
|---|---|---|---|---|
| curl | curl | curl | curl | command line tool for sending/receiving web requests |
| dig | bind-utils | bind-utils | bind9-dnsutils | DNS lookup tool, like nslookup but more useful |
| delv | bind-utils | bind-utils | bind9-dnsutils | DNS lookup with full DNSSEC validation and tracing |
| drill | N/A | ldns-utils | ldnsutils | dig-like DNS tool with DNSSEC signature chasing |
| git | git | git | git | version control; useful for debugging SSH/TLS transport issues |
| ipcalc | ipcalc | ipcalc | ipcalc | IP addressing calculator for subnet in CIDR notation |
| iperf3 | N/A | iperf3 | iperf3 | measure throughput between two machines |
| mtr | N/A | mtr | mtr-tiny | traceroute that keeps running and tracks per-hop loss |
| netcat | nc, nc6 | nmap-ncat | netcat-openbsd | swiss army knife for testing network connectivity |
| netstat | Windows netstat.exe | net-tools (or ss) | net-tools (or ss) | show listening ports and open connections |
| ntttcp | N/A | build from source | build from source | Microsoft’s network throughput benchmark |
| openssl | openssl | openssl | openssl | toolkit for testing SSL/TLS connections and certificates |
| openssh | openssh | openssh-clients | openssh-client | ssh, sftp, and scp |
| rsync | rsync | rsync | rsync | resumable, bandwidth-limited file synchronization over SSH |
| strace | N/A | strace | strace | trace the system calls a process makes (Linux) |
| tcpdump | N/A | tcpdump | tcpdump | capture packets for reading in Wireshark |
| testssl | runs in Cygwin bash | testssl | testssl.sh | scan a webserver’s TLS protocols, ciphers, and certificates |
| trippy | N/A | copr or cargo | PPA or cargo | mtr with a nicer live terminal UI |
| unfrl/dug | N/A | GitHub .rpm | GitHub .deb | query DNS servers worldwide to check propagation |
| watch | procps | procps-ng | procps | re-run a command on an interval and watch its output |
| whois | whois | whois | whois | look up who owns a domain, IP, or AS number |