Planning an IP Routing Solution

Plan a TCP / IP network infrastructure strategy.

• Plan an IP routing solution.

In this section, we analyze how to plan an IP routing solution. First, let's briefly review what IP routing is. A router is a device that looks at a packet that comes in one of its interfaces, analyzes the packet against its routing table (which can be dynamically or statically configured), and decides what segment of the network the packet needs to go to based on that table. In other words, if you have a router configured on your network (as your default gateway), and packets coming from the 10.10.1.0 segment need to get to 10.10.2.0, the router makes that decision. You can set up the router with static IP routes, which means that you hand-pick specific routes and enter them into the table manually, or you can have the router set up dynamically via a routing protocol such as Routing Information Protocol ( RIP ) or Open Shortest Path First ( OSPF ) . So, before we get into specifics, let's look at what you can use as a router.

If you have a large environment or depend heavily on your routing infrastructure, you may opt to use a hardware routing device such as one from Cisco, Nortel, or 3Com. If you are interested in saving money and using a software-based router, Windows Server 2003 can provide such a tool. A software-based routing solution, such as one using the Routing and Remote Access Service (RRAS) can be ideal on a small, properly segmented network with relatively light traffic between subnets. This doesn't mean you should use one over the other; it just means you can select one based on preference or the best price solution after you have performed a cost analysis. Regardless, knowledge of general routing and routers is needed for the 70-293 exam.

RRAS can provide a software-based router on top of Windows Server 2003. We will examine using RRAS to configure routing in detail in Chapter 4, "Planning, Implementing, and Maintaining Routing and Remote Access."