|
WebProWorld Networking Forum |
Broadband
USB modem to wireless router
Grateful for assistance, easiest way is to describe the symptoms. I had 1 computer(a)
connected to the internet via a speedtouch USB broadband modem on wanadoo. Two
other computers (b) and (c) networked to this one. Bought linksys wireless router,
removed speedtouch modem, replaced with router...
Home
network priority
I have 2 PCs and 1 laptop connected through a Linksys router. Both PCs are wired,
and the laptop is wireless. One of the PCs is my work (home office) PC, so I would
like it to have the priority to connect to the internet. The other two are used
by the kids, which is fine, but they don't need to go so fast just for their games...
Problem
with Arial Font on PC
For some unknown reason, I can only use Arial (font) in bold, italic or bold and
italic. Regular has disappeared altogether. As a result, because I use Arial for
everything, I can only view my documents in Italic or Bold font which is doing
my head in. I have tried copying...
What's
the best backup option?
Here I am with a hard drive full of very interesting client folders, some as large
as 10Gigs (video etc.). All these folders are stored and worked off a 160Gb external
hard drive. I often (not often enough)backup to DVD - then promptly leave the
DVDs in the same...
|
| Recent
Articles |
Senator Proposes Net Neutrality Bill
Ron Wyden (D-Or) has introduced legislation to prevent telecoms and cable companies
from developing a two-tiered network where fees would be charged to content providers
to prioritize their Internet traffic. Wyden's 'Internet Nondiscrimination Act'
attempts to derail the likes of AT&T, BellSouth, and Verizon from imposing additional
fees on companies like Google...
Open Source Vyatta Takes On Hardware
After years of open source projects like Linux and MySQL taking share from proprietary
software companies, hardware makers like Cisco and Juniper get to experience the
heart-stopping terror of open source hardware hitting the market. If Vyatta
gets to market, of course. Given the favorable attention given to the company...
Secure Routers Go Through Ceiling In 2005
A new study from Infonetics Research reported big numbers for secure routers in
2005. While price pressure drove prices down along with overall revenues, the
number of units moved climbed 121%. According to Infonetics numbers, overall revenues
were down 3% to 3.3 billion from 2004's $3.4 billion...
Net
Neutrality Divides On Party Lines
The potential to future innovators to build on the success of the Internet may
well hinge on network neutrality, but the two major political parties in Congress
see the issue differently. In a nutshell, or at least in a story
appearing on ZDNet, Democrats noted in the article side with the...
What is Microsoft Terminal Server?
Microsoft Terminal Server is a component of the Windows operating system that
allows users to remotely access servers and applications over the internet or
a local area network. Terminal Server runs on Windows Server 2003, Windows 2000
Server and Windows NT 4 Terminal Server. Client devices connecting to a Terminal
Server can be Windows workstations, Macintosh or Linux machines, mobile devices
and dumb terminals...
|
|
|
03.06.06
Cisco
CCNP / BSCI Exam Tutorial: Route Summarization
 By
Chris Bryant
Preparing to pass the BSCI exam and earn your Cisco CCNP?
Route summarization is just one of the many skills you´ll have to master in order
to earn your CCNP. Whether it´s RIP version 2, OSPF, or EIGRP, the BSCI exam will
demand that you can flawlessly configure route summarization.
Route summarization isn´t just important for the BSCI exam. It´s a valuable skill
to have in the real world as well. Correctly summarizing routes can lead to smaller
routing tables that are still able to route packets accurately - what I like to
call "concise and complete" routing tables.
The first skill you´ve got to have in order to work with route summarization is
binary math more specifically, you must be able to take multiple routes and come
up with both a summary route and mask to advertise to downstream routers. Given
the networks 100.16.0.0 /16, 100.17.0.0 /16, 100.18.0.0 /16, and 100.19.0.0 /16,
could you quickly come up with both the summary address and mask? All you need
to do is break the four network numbers down into binary strings. We know the
last two octets will all convert to the binary string 00000000, so in this article
we´ll only illustrate how to convert the first and second octet from decimal to
binary.
100 16 = 01100100 00010000
100 17 = 01100100 00010001
100 18 = 01100100 00010010
100 19 = 01100100 00010011
To come up with the summary route, just work from left to right and draw a line
where the four networks no longer have a bit in common. For these four networks,
that point comes between the 14th and 15th bits. This leaves us with this string:
01100100 000100xx. All you need to do is convert that string back to decimal,
which gives us 100 for the first octet and 16 for the second. (The two x values
are bits on the right side of the line, which aren´t used in calculating the summary
route.) Since we know that zero is the value for the last two octets, the resulting
summary network number is 100.16.0.0.
But we´re not done! We now have to come up with the summary mask to advertise
along with the summary route. To arrive at the summary route, write out a mask
in binary with a "1" for every bit to the left of the line we drew previously,
and a "0" for every bit to the right. That gives us the following string:
11111111 11111100 00000000 00000000
Converting that to dotted decimal, we arrive at the summary mask 255.252.0.0.
The correct summary network and mask to advertise are 100.16.0.0 252.0.0.0.
For the BSCI exam, emphasis is put on knowing how to advertise these summary routes
in RIPv2, EIGRP, and OSPF. For RIP v2 and EIGRP, route summarization happens at
the interface level - it's not configured under the protocol. On the interface
that should advertise the summary route, use the command "ip summary-address".
Here are examples of how the above summary route would be configured on ethernet0
in both RIPv2 and EIGRP.
R1(config-if)#ip summary-address rip 100.16.0.0 255.252.0.0
R1(config-if)#ip summary-address eigrp 100 100.16.0.0 255.252.0.0
The main difference between the two is that the EIGRP command must specify the
AS number - that´s what the "100" is in the middle of the EIGRP command. Since
RIPv2 does not use AS numbers, there´s no additional value needed in the configuration.
For OSPF, the commands differ. If you´re configuring inter-area route summarization,
use the "area range" command. The number following "area" is the area containing
the routes being summarized, not the area receiving the summary.
R1(config)#router ospf 1
R1(config-router)#area 1 range 100.16.0.0 255.252.0.0
If you are summarizing routes that are being redistributed into OSPF, use the
summary-address command under the OSPF routing process on the ASBR.
R1(config)#router ospf 1
R1(config-router)#summary-address 100.16.0.0 255.252.0.0
I speak from experience when I tell you that practice makes perfect on the BSCI
exam, especially with binary and summarization questions. The great thing about
these questions is that there are no grey areas with these questions - you either
know how to do it or you don´t. And with practice and an eye for detail, you can
master these skills, pass the exam, and become a CCNP. Here´s to your success
on these tough Cisco certification exams!
About the Author:
Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (www.thebryantadvantage.com),
home of FREE CCNA and CCNP tutorials and daily exam questions, as well as The
Ultimate CCNA and CCNP Study Packages.
For a FREE copy of his latest e-books, "How To Pass The CCNA" or "How To Pass
The CCNP", and for free daily exam question, visit the website and download your
copies! |
