Each PC on the NOBLE network must have an IP address to communicate on the network. IP addresses are assigned to each library in blocks of 254 addresses. It is the responsibility of the individual library to keep track of what addresses are in use, and what machines they belong to. It’s not a bad idea to keep a list and to label each PC with the last digit of it’s IP address.
Private Addresses
NOBLE has a firewall separating the NOBLE network (libraries as well as NOBLE itself) from the outside world. Behind the firewall we use what are known as private addresses. These addresses are non-routable on the Internet, which means that routers will ignore these addresses and not pass the information along. Private addresses are used as a security measure as well as a means to simplify a network.
The private addresses that NOBLE uses all start with 172.29.x.x or 10.x.x.x. These are the addresses that entered into each machine on the network. The private address for your workstation is at the top of this page.
Public Addresses
Public IP addresses are required if your PC is going to connect with the Internet. The firewall dynamically assigns a PC a public IP address number when it makes a connection to a resource on the Internet. The only address routers and computers on the Internet ever see is the public IP address.
The public address that NOBLE uses were assigned to us by our Internet Service Provider, which is Comcast. These address all start with 209.23.242..
The firewall assigns a number to each PC that browses the Internet. Each library has been assigned one number, and all outgoing connections from a library will use that same number. Each library has its own unique IP addresses to ensure that EBSCO and other vendors can determine which NOBLE library is trying to access their resources.
The only time you need to be aware of public IP addresses is when dealing with a vendor about authentication.