The easiest way to determine if your external IP address is static is to do the following:
Visit a site that will display your current external IP address, such as http://whatismyip.com . From Terminal, Mac and Linux users can try the command
Write down the address.
Restart your router.
Check your external IP address again, and compare it. If it has changed, you have a dynamic external IP address. If it has not changed, you may have a static IP address.
How to Check an IP Address
o get the depth information of your network interfaces like IP Address, MAC Address information, use the following command as shown below.
# ip addr show $ sudo ip addr show
mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 00:0c:29:28:fd:4c brd ff:ff:ff:ff:ff:ff inet 192.168.50.2/24 brd 192.168.50.255 scope global eth0 inet6 fe80::20c:29ff:fe28:fd4c/64 scope link valid_lft forever preferred_lft forever 3: eth1: mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 00:0c:29:28:fd:56 brd ff:ff:ff:ff:ff:ff inet 192.168.50.5/24 scope global eth1 inet6 fe80::20c:29ff:fe28:fd56/64 scope link valid_lft forever preferred_lft forever
Execute the following command from a terminal:
If your internal IP address is set as dynamic, it should contain something along the lines of
iface eth0 inet dhcp
And if it is static, it will contain
iface eth0 inet static