I am trying to set
exec-shield protection on Linux as described here but getting the following error on Ubuntu Linux server version 12.04 LTS:
sysctl -w kernel.exec-shield=1
error: “kernel.exec-shield” is an unknown key
How do I fix this problem and make sure exec-shield buffer overflow protection security feature turned on Ubuntu Linux?
I am under DoS attack. My cloud based server hosting company asked me to enable TCP SYN cookie protection to save my domain from SYN Attack. How do I turn on TCP Syn cookie protection under Ubuntu or CentOS Linux based server?
I run a BT client and few other server program on Linux. Sometime these programs get overloaded with too many connections and crashes. If I restart my apps, I see lots of old IPs in a TIME_WAIT state. How do I force and and close everything in a TIME_WAIT state under Linux operating systems?
How do I allow any ordinary users (such as my son or wife) to mount CD-ROMs, DVDs, USB drives, and other removable media on our home server powered by FreeBSD operating systems?
I‘m trying to use Cinelerra video editing and compositing software under Linux operating systems. However, I’m getting the following error:
MWindow::init_shm: /proc/sys/kernel/shmmax is 0×1000000.
It should be at least 0x7ffffff for cinelerra.
How do I fix this problem?
How do I find out that how many files are open and how many allowed in Linux server operating systems?
I setup a CentOS Linux based Linux server running as a gateway and firewall server. However, I’m getting the following messages in the /var/log/messages log file:
Dec 20 00:41:01 fw01 kernel: Neighbour table overflow.
Dec 20 00:41:01 fw01 last message repeated 20 times
OR
Dec 20 00:41:01 fw03 kernel: [ 8987.821184] Neighbour table overflow.
Dec 20 00:41:01 fw03 kernel: [ 8987.860465] printk: 100 messages suppressed.
Why does kernel throw “Neighbour table overflow” messages in syslog? How do I fix this problem under Debian / CentOS / RHEL / Fedora / Ubuntu Linux?