What Are Static Routes; Static Routes Example - 3Com SUPERSTACK 3 WEBCACHE 3000 User Manual

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HAPTER TATIC
What are Static
Routes?
Static Routes
Example
R
OUTES
Routes to remote networks are typically obtained dynamically through
routing protocols. However, you can also choose to provide routes
manually. These routes are referred to as Static Routes. A static route is
associated with an interface that represents the remote network. Unlike
dynamic routes, static routes are retained even if the router is restarted or
the interface is disabled.
Static routes are important for web caching because they allow you to
specify different default routers for particular networks or hosts. The
default router for the Webcache can sometimes be entirely the wrong
router to use for a particular network or server. Static routes provide
greater flexibility in transparent and inline deployments of the Webcache
within your network.
You can configure a static route on the Webcache by entering the IP
address and subnet mask of the remote network and the IP address of
the router for that network.
Static routes are essential in the following scenario:
The Webcache is deployed in Transparent mode with a SuperStack 3
I
Switch 4400.
For further information, see
4400, 4924 or 4950 with the Webcache"
The default router is on the WAN side of the Switch.
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There is also a LAN-side server.
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A request comes from the WAN to the Webcache for the LAN-side server.
If the request is a cache miss the Webcache has to retrieve the content
from the LAN-side server. To do this it sends a GET request to the default
router with the expectation that the packet will be routed to the LAN side
server.
However, the route to the LAN-side server from the default router is
through the Switch 4400. Subsequently the request is sent from the
default router to the Switch 4400 and is then again redirected to the
Webcache. The packet becomes trapped in an endless loop between the
Webcache, the default router and the Switch 4400, resulting in no
connectivity and eventually failure of the request.
"Deploying the SuperStack 3 Switch
on page 38.