Vou começar citando o bit relevante da documentação do nmap:
--host-timeout <time>
(Give up on slow target hosts)Some hosts simply take a long time to scan. This may be due to poorly performing or unreliable networking hardware or software, packet rate limiting, or a restrictive firewall. The slowest few percent of the scanned hosts can eat up a majority of the scan time. Sometimes it is best to cut your losses and skip those hosts initially. Specify --host-timeout with the maximum amount of time you are willing to wait. For example, specify 30m to ensure that Nmap doesn't waste more than half an hour on a single host. Note that Nmap may be scanning other hosts at the same time during that half an hour, so it isn't a complete loss. A host that times out is skipped. No port table, OS detection, or version detection results are printed for that host.
Isso significa que, se você chamar o nmap com --host-timeout 201
, ele
tentará obter informações para cada host varrido no máximo 201
segundos e, em seguida, se o host ainda não responder ou se houver
ainda restantes informações para obter a partir deste host, a varredura será
abandonado. Quanto ao valor específico 201, ou três minutos e vinte
um segundo, parece ser um valor de exemplo arbitrário.