Keep an Inventory of Your Network
Use Nmap to keep track of the devices and services on your network.
As we saw in
Nmap (http://www.insecure.org/nmap/) is free a tool
that can be used to conduct various sorts of scans on networks.
Normally when people think of using Nmap, they assume
it’s used to conduct some sort of nefarious network
reconnaissance in preparation for an attack. But as with all powerful
For example, simple TCP connect scans can be conducted without needing root privileges:
nmap rigelStarting nmap 3.48 ( http://www.insecure.org/nmap/ ) at 2003-12-15 17:42 MST Interesting ports on rigel (192.168.0.61): (The 1595 ports scanned but not shown below are in state: filtered) PORT STATE SERVICE 7/tcp open echo 9/tcp open discard 13/tcp open daytime 19/tcp open chargen 21/tcp open ftp 22/tcp open ssh 23/tcp open telnet 25/tcp open smtp 37/tcp open time 79/tcp open finger 111/tcp open rpcbind 512/tcp open exec 513/tcp open login 514/tcp open shell 587/tcp open submission 4045/tcp open lockd 7100/tcp open font-service 32771/tcp open sometimes-rpc5 32772/tcp open sometimes-rpc7 32773/tcp open sometimes-rpc9 32774/tcp open sometimes-rpc11 32775/tcp open sometimes-rpc13 32776/tcp open sometimes-rpc15 32777/tcp open sometimes-rpc17 Nmap run completed -- 1 IP address (1 host up) scanned in 75.992 seconds
This is tremendously useful for checking on the state of your own machines. You could probably ...