Static and Portable IP blocks

SoftLayer currently offers 2 different types of IP blocks, Static and Portable. The different types of IP blocks are designed to be used in different ways. Below is a brief description on each type of block that is offered by SoftLayer as well as a section on using these IP addresses within a Virtual Machine.

 

Static IP Block

The most popular type of IP block within the SoftLayer network is the Static IP block. A Static IP block is a block of IP’s that are routed directly to a specific IP on our network. Every IP address in a Static block is usable on the server. One of the primary benefits to a Static block of IP’s is that you do not lose the first two and last IP from the block. Below is an example of a small Static IP block 192.168.0.4/30.

·192.168.0.4 – Usable Address

·192.168.0.5 – Usable Address

·192.168.0.6 – Usable Address

·192.168.0.7 – Usable Address

As this example shows, all 4 IP’s in this block would be available to the server, while with a portable block, only a single IP from this block would actually be useable on the server due to the network, gateway and broadcast IP’s being bound directly to the VLAN.  Note:  There is a special caveat to be able to use all of the IPs though, as using the assigned subnet mask will only let you use all but one (the broadcast IP) of the IPs.  In order to use all of the IPs, the trick is to use the subnet mask of 255.255.255.255 instead.  That will allow you to use all of the IPs in the subnet, rather than missing out on the broadcast IP.

Portable IP Block

A SoftLayer Portable IP block is considered to be any IP block that can be used on multiple servers within a single VLAN concurrently. We currently offer two different types of Portable IP blocks. The first type of Portable IP block is a “Routed to VLAN” block. This is a Static IP block that is routed to an entire VLAN rather than a specific IP address. The other type of Portable IP Block is “Secondary on VLAN”. A Secondary on VLAN block is designed to be used within a Virtual Environment.

The primary difference between the two is the number of IP’s that are available for use. A Routed to VLAN block, like a static block provides the user access to all IPs within the block. A Secondary on VLAN block however requires that the Network, Gateway and Broadcast IP’s be bound directly to the VLAN rendering them unusable by the user. A Routed to VLAN block would be used when the user wanted to use any IP within that block on any server within the VLAN at any time. The Secondary on VLAN block is used in conjunction with a Virtual Machine. More information on Secondary on VLAN blocks is provided under the IP’s for Virtual Machines section.

When ordering a Portable IP block, by default SoftLayer will provide you with a Secondary on VLAN block. If you wish to have this block converted to a Routed to VLAN block for use on your servers within a single VLAN, please open a support ticket requesting that this block be converted to a Routed to VLAN block
 

IP’s in PODs that support Hot Standby Router Protocol (HSRP)

It is important to note that PODs that take advantage of the Hot Standby Router Protocol (HSRP) utilize 2 more IPv4 addresses, one for the Vlan interface of each participating router, out of every “Secondary on VLAN” block configured on the Vlan.

Below is an example of a Secondary on VLAN block 192.168.0.4/28 being used for multiple Virtual Machines in a HRSP POD.

 

 

·192.168.0.0 –  Network Address
·192.168.0.1 –  Gateway Address
·192.168.0.2 –  Router A Vlan Interface
·192.168.0.3 –  Router B Vlan Interface
·192.168.0.4 –  VPS1
·192.168.0.5 –  VPS2
·192.168.0.6 –  VPS3
·192.168.0.8 –  VPS4
·192.168.0.9 –  VPS5
·192.168.0.10 – VPS6
·192.168.0.11 – VPS7
·192.168.0.12 – VPS8
·192.168.0.13 – VPS9
·192.168.0.14 – VPS10
·192.168.0.15 – Broadcast Address

 

IP’s for Virtual Machines

Virtual Machines are growing in popularity every day. This section will provide you with the information on what type of IP blocks are required to be used in a VM. The information provided is based on Microsoft Hyper-V which is supported by SoftLayer.

Every Virtual Machine that will be connected to the SoftLayer network in a virtual environment requires a primary IP address from a portable block of IP’s. The reason for this, is that Hyper-V requires each Virtual Machine to provide a Network, Gateway and Broadcast address on the same subnet as the primary IP assigned to the Virtual Machine. One advantage to our network configuration is that a single Secondary on VLAN block can be used for multiple Virtual Machines. Below is an example of a Secondary on VLAN block 192.168.0.4/29 being used for multiple Virtual Machines

·192.168.0.0 – Network Address

·192.168.0.1 – Gateway Address

·192.168.0.2 – VPS1

·192.168.0.3 – VPS1

·192.168.0.4 – VPS1

·192.168.0.5 – VPS2

·192.168.0.6 – VPS3

·192.168.0.7 – Broadcast Address

As the example shows, this Secondary on VLAN block provides 5 usable IP address out of the 8 IP addresses in the block bound across 3 different Virtual Machines. This brings up the question “how do I add more IP’s to a Virtual Machine if all the IP’s on the Portable block are used?”. This problem can be resolved through the use of a Static block, or a Routed to VLAN Portable block.

To use a Static Block within a Virtual Machine, first order a new Static IP block from the portal. When you order this block you will be able to select the IP address you wish to have this block routed to. By selecting the IP address that is assigned to the Virtual Machine. The new block will be routed specifically to that Virtual Machine. You will then be able to bind the new block of IP’s directly to that Virtual Machine and begin using them immediately.

Alternately, if you wish for the new block to be usable by more than one Virtual Machine, this is done by using a Routed to VLAN block. A Routed to VLAN block is available by purchasing a Portable IP block from the portal and selecting the VLAN that the IP address of the Virtual Machine resides. Once the IP block is created, it will then be available for use on any Server or Virtual Machine on that VLAN.

For specific instructions on how to bind your portable IP's to a Virtual Machine please see Virtual Machine Network Setup.