Tools › Cheat sheets › Networking & Security
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Networking & Security cheat sheets
Connections, DNS, firewalls, SSH, certificates and subnets.
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SSHConnect, copy files, create keys and tunnel traffic.
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curlMake HTTP requests, send data and debug APIs.
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Linux networkingip, ss, ping, dig and friends for diagnosing connectivity.
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ufwManage the Ubuntu firewall with simple commands.
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OpenSSLKeys, certificates, CSRs and TLS checks.
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Certbot (Let's Encrypt)Get and renew free TLS certificates.
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Subnet / CIDRMasks and host counts from /8 to /30.
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iptablesList, add and delete Linux firewall rules, plus NAT.