I run a web-server and I would like to log packets with un-routable source addresses on Linux operating system. How can I log spoofed packets on Debian / Ubuntu / CentOS / RHEL / Linux based server? How can I log a Martian packet (packet from Mars) on Linux operating systems?


I am using NFS server version 4.x on a CentOS/RHEL based system. I’m mounting my shared /var/www/ directory on five Apache based nodes using the following syntax:

mount -t nfs4 -o rw,intr,hard,proto=tcp rocknas02:/httproot/www /var/www/

I noticed that due to bug in my app user can sometime upload executable or other device files to get out of chrooted Apache server. How can I prevent such security issues on a CentOS or RHEL based NFS client and sever setup?


I manage MS-Windows server and recently started to play with OpenBSD server. How do I reload or restart the dhcpd server on OpenBSD using shell command line option?

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I am running Red Hat Enterprise Linux on IBM based system. How do I display bandwidth usage on an interface by host in real time using command line option? How do I monitor bandwidth usage in a real time on RHEL or CentOS Linux based server? How can I install iftop utility on CentOS or RHEL server using the yum command?


I am a new CentOS Linux sysadmin. How can I add static route On CentOS Enterprise Linux server running on HP amd64 server?

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How do I find out what is listing or using tcp port number 80 on Linux based systems using command line options?


I know how to send WOL command using Linux or FreeBSD wake command. But, how do I send Wake on LAN (WOL) frames to hosts on a local Ethernet network using Apple OS X Unix operating systems to wake up my servers or nas devices?