Static Routes Example

Adding and Managing Static Routes

The figure below shows the network configuration for the example:


In this example Gateway 1 (GW-1) is connected to the Internet. There is no routing occurring on the interface connected to the Internet (no OSPF, or BGP). Between Switch 1 (SW-1) and Switch 2 (SW-2) there is a corporate WAN. There is also no routing occurring on this link. We want the remote PC LAN to have Internet access. To reduce the amount of traffic on the corporate WAN and comply with the Internet provider, we will use static routes.

Static routes are routes that are administered manually. They do not change and are not dynamic (hence the name). If a link goes down, there is no fail over method for static routes. Although this is not a issue on single link connections (connections that rely on one link for connectivity) it makes debugging of link failures more difficult. You do however reduce the amount of traffic by eliminating the routing updates that routing protocols require.

There are many areas where static routes apply, such as in connections to the Internet, across corporate WANs, and to create routing boundaries between two areas.

Creating/Removing Static Routes

For the above example we will create one static default route to the Internet through 22.1/22, and a static route across the Corporate WAN to the remote PC LAN across 26.68/30.

Static Default Route

  1. Use clearVISN IP Switch Managerto connect to Gateway 1.
  2. Click .
  3. Click the Static Routes link in the Routing Configuration section.
  4. Click the on radio button in the Default Static Route field.
  5. Click .
  6. In the default gateway IP Address edit box enter: 205.226.22.1.
  7. Click .
    You should now have one static default route in your routing tables on Gateway 1. In order for the rest of the network to know about this route you must then advertise the static route to OSPF. See redistributing From Static Routes to OSPF External . After completing this task any Gateway connected to Switch 1 will have this default route of 22.1 in the routing tables. Any packet not destined for the 22.0/22 net will then be directed towards 22.1.
  8. Connect to Switch 2 using clearVISN IP Switch Manager and repeat steps 2-7 replacing the default gateway address with 205.226.26.69.

Static Routes (non default)

  1. Click .
  2. Click the Static Routes link in the Routing Configuration section.
  3. In the Network Prefix for New Static Route edit box enter: 205.226.24.0.
  4. In the Mask Length edit box enter: 24.
  5. In the Next Hop edit box enter: 205.226.26.70.

    If you have configured OSPF or RIP on your remote office network then you will now have connectivity to the Internet.

Copyright © 1997 Ipsilon Networks, Inc.
Portions copyright © Digital Equipment Corporation 1998. All rights reserved.
Updated January 8, 1998
Send comments to Digital Equipment Corporation, doc-quality@lkg.mts.dec.com