|
|
|
|
Home / Computers / Computer Certification
Cisco CCNP Certification / BSCI Exam Tutorial: Floating Static Routes
By:Chris Bryant, CCIE #12933
Passing the BSCI exam and earning your CCNP certification demands that you add greatly to the networking skills foundation you created when you studied for your CCNA certification. You learned quite a bit about static routing and default static routing when you passed the CCNA test, and it does seem like that should be all you need to know about static routing, right?
One thing you'll learn as you continue to earn Cisco certifications is that there's always something else to learn! You may have heard the term "floating static route", which does suggest some interesting mental pictures. "Floating"? Floating on what?
In a way, a floating static route is "floating" in your routing table. A floating static route is a route that will be used only if routes for the same destination but with a lower administrative distance are removed from the table. For example, you could be using an OSPF-discovered route as your primary route to a given destination, and the floating static route would serve as a backup route that would be used only if the OSPF route leaves the routing table.
Now, how can that happen? After all, OSPF has an administrative distance of 110 and static routes have ADs of one or zero, depending on whether it's configured with a next-hop IP address or a local exit interface. One way or the other, 1 and 0 are still less than 110!
When you want to configure a floating static route, you must assign the route an AD higher than that of the primary route. In this case, we've got to create a static route with an AD higher than 110. We do this by using the "distance" option at the end of the "ip route" command.
R1(config)#ip route 110.1.1.0 255.255.255.0 172.12.123.1 ?
<1-255> Distance metric for this route
name Specify name of the next hop
permanent permanent route
tag Set tag for this route
R1(config)#ip route 110.1.1.0 255.255.255.0 172.12.123.1 111
The number entered at the very end of the "ip route" command is the AD of that route. If there is an OSPF route for 110.1.1.0 /24, that will be the primary route, and the floating static route will not be used unless the OSPF route is taken out of the routing table.
Floating static routes aren't just a good thing to know for the BSCI exam and your CCNP certification pursuit - they're very practical in the real world as well.
Article Source: http://www.dailynewarticles.com
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage, home of free CCNP and CCNA tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages.
For a FREE copy of his latest e-books, “How To Pass The CCNA” and “How To Pass The CCNP”, just visit the website! You can also get FREE CCNA and CCNP exam questions every day! Pass the www.thebryantadvantage.com/CCNPStoreBSCI.htm ">CCNP exam with The Bryant Advantage!
More Articles from Computer Certification Category:
Cisco CCNP Certification / BCMSN Exam Tutorial: Writing QoS Policy
Cisco CCNP / BCSI Exam Tutorial: Configuring EIGRP Packet Authentication
Cisco CCNP / BSCI Certification: Introduction To ISIS Terminology
What To Expect When Taking Your First Cisco Certification Exam
Cisco CCNA / CCNP Home Lab: Why You Need An ISDN Simulator
Be Certifiable! The Basics Of MCSE And MCP
Cisco CCNP / BCSI Exam Tutorial: Broadcasts And The IP Helper-Address Command
Webroot Window Washer
Cisco CCNA / CCNP Home Lab Tutorial: Using 2520 Routers
CCNA / CCNP Home Lab Tutorial: The VLAN.DAT File
Cisco CCNP / BCMSN Exam Tutorial: Changing Root Bridge Election Results
CCNP Certification / BCMSN Exam Tutorial: HSRP MAC Addresses And Timers
Cisco CCNP / BCMSN Exam Tutorial: Switches, QoS, And Cisco's Networking Model
Cisco CCNA Exam Tutorial: Troubleshooting Directly Connected Serial Interfaces
How To Earn Cisco’s Firewall Specialist Certification
|
|
