Static IP Setup

Setting up Static IP for Your Business

Use the links below, skip down to your topic of choice or simply scroll through the topics to learn more about setting up static IPs.


What is an IP Address?

An IP Address is a unique set of numbers (xxx.xxx.xxx.xxx) that identify each computer, cable modem, router, or other Internet capable device that is directly connected to the Internet. An IP address is required to navigate the Internet.

What is a Static IP Address?

A Static IP Address is a number that is assigned to a device to be its permanent address on the Internet.

What is a Dynamic IP Address?

When a customer logs on to the Internet, they receive a Dynamic IP Address (or temporary address) for the duration of that Internet session, or for some other specified amount of time. Once the customer disconnects from the Internet, the Dynamic IP address may return to the IP address pool so it can be assigned to another user. Even if the customer reconnects immediately, they may not be assigned the same IP address from the pool.

Does an RCN Business customer's Dynamic IP address change often on the RCN network?

Dynamic IP address can change without notice, although they change infrequently under normal RCN network operations. Below are some situations that can cause the Dynamic IP to change.

  • Lease expiration: Connected device is disconnected from the network for an extended period of time.
  • Network Reconfiguration: Adding network capacity can mean the addition, or the relocation of customers from one "chassis" to another. There are occasions when RCN will replace smaller network blocks. If a customer is on a block that is removed, their IP address will change.
  • Equipment change: In the event a customer with a "detached" router replaces that router, or connected device, to the modem.
  • Customers with a 3-in-1 or device with integrated modem/router will get a new IP address if their modem/router combo is replaced or changed. This is another example of new equipment.
  • Note: Swapping a *MODEM* by itself does not change the customer’s IP address.
  • The systems are setup to prevent an IP number change. In many instances, customers have held the same IP address for an extended period of time.

Why would you need a Static IP?

  1. Static IP addresses are intended to be used to host Web or E-mail Servers, in addition to normal Internet activities. If a customer is planning to host their own E-Mail or FTP server, or Virtual Private Network, they will need a Static IP.
  2. If you wish to send more than 400 email messages per hour, a Static IP is required. A Static IP will automatically boost the outgoing mail quota from 400 to 5,000 messages per hour. A customer who hosts a newsletter or mailing list would also benefit from a Static IP.
  3. Telecommuters who require access to their company's local network, often need to supply their company's firewall administrator with a Static IP. This will permit the administrator to set up secure access.

Does RCN assign a "true" permanent Static IP?

Yes. A Static IP by definition is an address that does not change. The IP address that the modem has will not change except in those unforeseen circumstances.

Are Static IPs associated with a particular device or piece of hardware?

An IP address by its nature is associated through a duration of time with a particular piece of hardware. However, The Static IP address can be utilized for different customer equipment, assuming the equipment resides in the same location.

Are customers allowed to attach Web servers or e-mail servers to the RCN network via a Static IP?

Yes. At this time, customers are allowed to attach a Web server or e-mail server to the RCN network. Customers with Dynamic IP addresses are NOT permitted to host servers.

How many Static IPs may I have?

Customers may purchase subnet blocks utilizing one, five or 13 usable Static IP addresses.

Will my Static IP ever change?

A customer’s Static IP address will remain the same for a long period of time. On occasion, RCN will need to move equipment and reallocate addresses. If this occurs, RCN will give the customer as much notice as possible for the shift to minimize the inconvenience.

How long does it take before the customer has the Static IP?

The Static IP is available immediately after the modem goes online.

How many dynamic IPs does RCN provide?

RCN provides customers with one Dynamic IP address with your cable modem service. Additional Dynamic IPs can be purchased separately.

How many email messages can the customer send per hour with a Static IP?

5,000 per hour

Are Outbound Ports 80 and 25 blocked for customers with a Static IP?

No, however these ports are blocked for customers with a Dynamic IP.

How to Manually Assign IP Addresses for Subnet IP Subscribers in all Supported Operating Systems

Operating System Step by Step Set-up
Windows 2000
  1. Right click My Network Places >> Click Properties
  2. Right click the Local Area Connection icon >> Click Properties >> Highlight Internet Protocol TCP/IP by clicking on it >> Click the properties button
  3. Select the Use the following IP address radio button >> Enter the IP the customer wants to use for this device in the IP Address field.
  4. Remember, the first two IP addresses and the Last IP address are not useable addresses
      Enter the Subnet Mask in In the Subnet Mask field
    • If the customer subscribes to a 16 IP block the subnet is always - 255.255.255.240
    • If the customer subscribes to a 8 IP block the subnet is always - 255.255.255.248
    • Enter the Default Gateway
    • The Default gateway is always the Second IP address in the subnet block.
  5. Select the Use the following DNS server addresses radio button >> Enter the standard RCN DNS (207.172.3.8, 207.172.3.9, 207.172.3.10, 207.172.3.11) >> Click OK >> Restart the computer if prompted.
Windows XP
  1. Click Start | Control Panel -- OR -- Start | Settings | Control Panel when in the Classic Start Menu >> Click Network and Internet Connections >> Click Network Connections >> When in classic view double click network connections.
  2. Right click the Local Area Connection icon >> Click Properties >> Highlight Internet Protocol TCP/IP by clicking on it >> Click the properties button
  3. Select the Use the following IP address radio button >> Enter the IP the customer wants to use for this device in the IP Address field.
  4. Remember, the first two IP addresses and the Last IP address are not useable addresses
      Enter the Subnet Mask in In the Subnet Mask field
    • If the customer subscribes to a 16 IP block the subnet is always - 255.255.255.240
    • If the customer subscribes to a 8 IP block the subnet is always - 255.255.255.248
    • Enter the Default Gateway
    • The Default gateway is always the Second IP address in the subnet block.
  5. Select the Use the following DNS server addresses radio button >> Enter the standard RCN DNS (207.172.3.8, 207.172.3.9, 207.172.3.10, 207.172.3.11) >> Click OK >> Restart the computer if prompted.
Windows Vista/7/8
  1. Click Start | Control Panel -- OR -- Start | Settings | Control Panel when in the Classic Start Menu >> Click Network and Internet >> Click Network Connections >> Click Network and Sharing Center >> Click Manage network connections from the left menu
  2. Right click the Local Area Connection icon >> Click Properties >> Click Continue if presented with "Windows needs your permission to continue" >> Highlight Internet Protocol Version 4 (TCP/IPv4) by clicking on it >> Click the properties button
  3. Select the Use the following IP address radio button >> Enter the IP the customer wants to use for this device in the IP Address field.
  4. Remember, the first two IP addresses and the Last IP address are not useable addresses
      Enter the Subnet Mask in In the Subnet Mask field
    • If the customer subscribes to a 16 IP block the subnet is always - 255.255.255.240
    • If the customer subscribes to a 8 IP block the subnet is always - 255.255.255.248
    • Enter the Default Gateway
    • The Default gateway is always the Second IP address in the subnet block.
  5. Select the Use the following DNS server addresses radio button >> Enter the standard RCN DNS (207.172.3.8, 207.172.3.9, 207.172.3.10, 207.172.3.11) >> Click OK >> Restart the computer if prompted.
Mac OS X.x
  1. Click the Apple Menu | System preferences >> Click Network >> Select Built In Ethernet from the Show drop down menu
  2. Click the Configure IPv4 drop down menu >> Select Manually
  3. Select the Use the following IP address radio button >> Enter the IP the customer wants to use for this device in the IP Address field.
  4. Enter the IP you to use for this device in the IP Address field. Remember, the first two IP addresses and the Last IP address are not useable addresses
      Enter the Subnet Mask in In the Subnet Mask field
    • If the customer subscribes to a 16 IP block the subnet is always - 255.255.255.240
    • If the customer subscribes to a 8 IP block the subnet is always - 255.255.255.248
    • Enter the Default Gateway
    • The Default gateway is always the Second IP address in the subnet block.
  5. Select the Use the following DNS server addresses radio button >> Enter the standard RCN DNS (207.172.3.8, 207.172.3.9, 207.172.3.10, 207.172.3.11) >> Click OK >> Restart the computer if prompted.