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linux:sysadmin [2018/07/24 16:56]
mstraub [/etc/crontab]
linux:sysadmin [2020/08/20 11:59]
mstraub [Check Open Ports & Connections]
Line 677: Line 677:
 <code bash> <code bash>
 netstat -a           # print open & listening internet connections and Unix domain sockets netstat -a           # print open & listening internet connections and Unix domain sockets
-netstat -a -t        # print only tcp connections (-u for udp) +netstat -a -t -p     # print only tcp connections (-u for udp) and the associated pid
 netstat -s           # print statistics about e.g. nr of received packets netstat -s           # print statistics about e.g. nr of received packets
 netstat -r           # print the kernel routing table netstat -r           # print the kernel routing table
Line 686: Line 686:
 nmap localhost ​      # print open ports on current machine (only a selection of common ports) nmap localhost ​      # print open ports on current machine (only a selection of common ports)
 nmap -p 1-9999 host  # print open ports on a host (with a defined port range) nmap -p 1-9999 host  # print open ports on a host (with a defined port range)
 +nmap -Pn -p 1-9999 host  # as above, but skip host discovery (helpful if above probe fails) ​
 nmap -A -T4 host     # print open ports with enabled version detection (-A) and don't wait too long (-T4) nmap -A -T4 host     # print open ports with enabled version detection (-A) and don't wait too long (-T4)
 </​code>​ </​code>​
linux/sysadmin.txt ยท Last modified: 2020/08/20 11:59 by mstraub