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linux:sysadmin:net:network_lookup_and_scanning

Network Lookup and Scanning

See which application is listening on which interfaces and ports:

netstat -l -n -p -t -u -w

Scanning with nmap

Command Description
nmap -sP -v 147.87.80*scann the subnet for reachable hosts
nmap -oX <filename> -v -sS <ip>tcp syn-scann, saves the output to a file
nmap -oX <filename> -v -sU -P0 <ip>same as above for udp but without pinging

Get DNS information

Command Description
dig <domainname> +recurseget informations about the domain (recursive)
dig @<ip> <domainname> axfrget all information about the ns
dig <domainname> nssame as above
nslookup <domainname>simpler tool as dig, not recursive
host -a <hostname>finds host information (NS, SOA …) ! name server must exist

Analyze network traffic whit tcpdump

Command Description
tcpdump -v -i <interface> -p tcplistening on TCP network traffic on specified interface (verbose output)

Using good old ping

Command Description
ping -c / -f / -i / -I / -n / -R / -sping with options: count / flood/ wait / device / numeric / record route / size
/srv/wiki.niwos.com/data/pages/linux/sysadmin/net/network_lookup_and_scanning.txt · Last modified: 2010/10/19 08:37 (external edit)