If you need to automate firewall settings for AWS by service this is a real time source of info you can pro grammatically use. https://ip-ranges.amazonaws.com/ip-ranges.json nJoy 😉
Edit /etc/sysconfig/network and set “NETWORKING_IPV6” to “no” For 5.4 and later, replace in /etc/modprobe.conf alias ipv6 off by options ipv6 disable=1 Alternative (which might be easier and works on any release with /etc/modprobe.d): # touch /etc/modprobe.d/disable-ipv6.conf # echo "install ipv6 /bin/true" >> /etc/modprobe.d/disable-ipv6.conf For CentOS 5.3 or older, add the following to /etc/modprobe.conf :…
To monitor TCP and UDP connections the following command is very useful: netstat -t -u to have a continuous update use the watch command: watch netstat -t -u There is a much stronger tool for real time analysis called iptraf. It is quite self explanatory : at command line run iptraf This tool has many functions…
Display default route The following three commands display the current routing table: # route Output: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.1.0 * 255.255.255.0 U 0 0 0 ra0 default dsl-router 0.0.0.0 UG 0 0 0 ra0 # /sbin/route Output: Kernel IP routing table Destination Gateway Genmask Flags Metric…
The following command gives a neat list of the Devices and their IPs / details without all the gruesome details. ifconfig | egrep  "Link|inet" A sample result would be: [root@testarossa-00-0c-29-47-8f-35 vm]# ifconfig | egrep "Link|inet" eth0 Link encap:Ethernet HWaddr 00:0C:29:47:8F:2B inet addr:192.168.47.135 Bcast:192.168.47.255 Mask:255.255.255.0 eth1 Link encap:Ethernet HWaddr 00:0C:29:47:8F:35 inet addr:192.168.1.71 Bcast:192.168.1.255 Mask:255.255.255.0 lo Link…
