I have written a short bash function for measuring website metrics such as DNS lookup, redirects, redirect time, the first byte (TTFB), connect time and the total time. Short version (Only TTFB) function ttfb() { if [ $# -eq 0 ] then echo “Usage: ttfb url” else curl -o /dev/null \ -H ‘Cache-Control: no-cache’ \…
How to get the real IP address on Nginx when you use Cloudflare. If you want to get the real IP address on Nginx when you use Cloudflare, you can use the ngx_http_realip_module module. You can find here more information regarding this module: http://nginx.org/en/docs/http/ngx_http_realip_module.html On Nginx, http section: http { …… … other options ……
How to block access by user agent in Nginx. In this configuration, i will use ngx_http_map_module. Inside http section: include /etc/nginx/blacklist; Inside server section (virtual host). We will return 444 status code. if ($block_ua) { return 444; } The blacklist file (example) map $http_user_agent $block_ua { default 0; ~*profound 1; ~*scrapyproject 1; ~*netcrawler 1; ~*nmap…
arp-scan is a very fast ARP packet scanner that shows every active IPv4 device on your subnet. Since ARP is non-routable, this type of scanner only works on the local LAN (local subnet or network segment). arp-scan shows all active devices even if they have firewalls. Devices cannot hide from ARP packets like they can…
Httping is like ‘ping’ but for http-requests. Give it an url, and it’ll show you how long it takes to connect, send a request and retrieve the reply (only the headers). Be aware that the transmission across the network also takes time! So it measures the latency of the webserver + network. Installing on Debian:…