1. route - show / manipulate the IP routing table
see also: ip route
2. nslookup
3. ifconfig -a
4. hostname
5. ping
6. ethtool eth0
7. netstat -rn
8. top
9. vmstat
10. w
11.uptime
12. ps
13. free
14. iostat
15.sar
16. mpstat
17.pmap
18. /proc file system - various kernet stats# cat /proc/cpuinfo
# cat /proc/meminfo
# cat /proc/zoneinfo
# cat /proc/mounts
# cat /proc/version
19. lsof
20. last
21. df
22. du
23. kill
24. traceroute
25. rsync
26. rpm
27. tar
28. pwd
29. lsb_rlease -a
30. uname -a [-prints the name, version and other details about the current machine and the operating system running on it.]