Question

Routing two different address ranges with Cisco 6500

Asked by: linesplice

Question to all the Cisco smarty's:

Our ISP has given us a /26 block of IP's and a /30 block of IP's.  The /30 block is for our routers (we have two).  The /26 block is for all of our machines.  I think we have extra IP's available to use in the /30, but I'm not sure how to get it routed, not being a Cisco wiz.  Can anyone help?  I can clarify if necessary.  I want to route one or two of the /30 IP's to an internal interface.

Thanks!

Here's the config of our primary router (IP's replaced with dummy's):


Router-1#show config                      
Using 1392 out of 129016 bytes                              
!
! Last configuration change at 08:19:37 EDT Tue Aug 12 2003                                                          
! NVRAM config last updated at 08:19:45 EDT Tue Aug 12 2003                                                          
!
version 12.2            
service timestamps debug uptime                              
service timestamps log datetime                              
service password-encryption                          
!
hostname router-1                  
!
logging buffered 4096 debugging                              
enable password 7 1414430800C52F393E                                    
!
clock timezone EDT -5                    
ip subnet-zero              
!
!
!
!
!
!
interface FastEthernet0/0                        
 description Uplink to ISP                        
 ip address 123.456.789.150 255.255.255.252                                        
 speed 100          
 full-duplex            
!
interface FastEthernet0/1                        
 description Customer inside int                                
 ip address 987.654.321.3 255.255.255.192                                        
 no ip redirects                
 speed 100          
 full-duplex            
 standby ip 987.654.321.1                        
 standby priority 250                    
 standby preempt                
 standby track FastEthernet0/0 100                                  
 standby 1 ip 987.654.321.2                          
 standby 1 priority 200                      
 standby 1 preempt                  
!
interface Ethernet1/0                    
 description Crosslink to rtr b                              
 ip address 123.456.789.157 255.255.255.252                                        
 half-duplex            
!
interface Ethernet1/1                    
 no ip add        
 half-duplex            
!
interface Ethernet1/2                    
 no ip address              
 shutdown        
 half-duplex            
!
interface Ethernet1/3
 no ip address
 shutdown
 half-duplex
!
ip classless
ip route 0.0.0.0 0.0.0.0 123.456.789.149
ip route 0.0.0.0 0.0.0.0 123.456.789.158 10
ip route 987.654.321.0 255.255.255. 123.456.789.158 10
no ip http server
!
!
line con 0
line aux 0
line vty 0 4
 password 7 0007430B081A0F1415
 login
!
ntp clock-period 17179912
ntp server 543.345.678.1
end

router-1#



This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.

Subscribe now for full access to Experts Exchange and get

Instant Access to this Solution

  • Plus...
  • 30 Day FREE access, no risk, no obligation
  • Collaborate with the world's top tech experts
  • Unlimited access to our exclusive solution database
  • Never be left without tech help again

Subscribe Now

Asked On
2003-08-15 at 08:51:03ID20710823
Tags

6500

,

cisco

,

routing

,

ip

Topic

Network Routers

Participating Experts
2
Points
250
Comments
5

Trusted by hundreds of thousands everyday for fast, accurate and reliable tech support.

  • "The time we save is the biggest benefit of Experts Exchange to Warner Bros. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange." Mike Kapnisakis, Warner Bros.
  • "Our team likes having a resource that is more secure than just using Google and most experts using this service really know their stuff. It's nice to look here first versus using Google." Dayna Sellner, Lockheed Martin
  • "Anytime that I've been stumped with a problem, 9 out of 10 times Experts Exchange has either the accepted solution or an open discussion of the potential solution to the problem." Kenny Red, eBay Inc.

See what Experts Exchange can do for you.

Got a question?

We've got the answer.

Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.

Screenshot of Experts Exchange Knowledgebase

Need individual assistance?

Our experts are ready to help.

If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.

Screenshot of Experts Exchange Knowledgebase

Want to learn from the best?

Read articles from industry experts.

Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.

Screenshot of an Article

Working on a long term project?

Store your work and research.

Save solutions to your questions, answers you’ve discovered through searching plus helpful articles in your personal knowledgebase for easy future access.

Screenshot of Experts Exchange Knowledgebase

Access the answers to your technology questions today.

Subscribe Now

30-day free trial. Register in 60 seconds.

What Makes Experts Exchange Unique?

Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.

Trusted by the world's most respected brands.

image of each brand's logo

Faithfully serving IT professionals since 1996.

Experts Exchange Logo

Try it out and discover for yourself.

Subscribe Now

30-day free trial. Register in 60 seconds.

Related Solutions

  1. Command "ip classless' on Cisco
    Hi! I see an comman "ip classless" on Cisco router, and I don't know what does it use for? How can you help me? Thanks
  2. Cisco for Identifying Uplink ports
    We have 1800 switches in our network. I need to locate which port on whitch switch is used as an uplink port. We uses only Cisco Swtiches. Is it possible to use CiscoWorks for this task? How?
  3. How can I configere the IP Classless for Cisco router 1841?
    I have onfigured a Cisco router in location1 with the following: interface FastEthernet0/0 ip address 172.31.58.234 255.255.255.252 duplex auto speed auto ! interface FastEthernet0/1...
  4. Classful and Classless Network
    Can someone tell me the difference between classful network and classless network? is it the subnet mask that determines if a network is classful or classless? example :15.14.20.11/8 it looks to me classful because of the first octet (15) and the /8 10.0....

Free Tech Articles

  1. WARNING: 5 Reasons why you should NEVER fix a computer for free.
    It is in our nature to love the puzzle. We are obsessed. The lot of us. We love puzzles. We love the challenge. We thrive on finding the answer. We hate disarray. It bothers us deep in our soul. W...
  2. SCCM OSD Basic troubleshooting
    SCCM 2007 OSD is a fantastic way to deploy operating systems, however, like most things SCCM issues can sometimes be difficult to resolve due to the sheer volume of logs to sift through and the dispe...
  3. Migrate Small Business Server 2003 to Exchange 2010 and Windows 2008 R2
    This guide is intended to provide step by step instructions on how to migrate from Small Business Server 2003 to Windows 2008 R2 with Exchange 2010. For this migration to work you will need the fo...
  4. Create a Win7 Gadget
    This article shows you how to create a simple "Gadget" -- a sort of mini-application supported by Windows 7 and Vista. Gadgets can be dropped anywhere on the desktop to provide instant information, ...
  5. Outlook continually prompting for username and password
    There have been a lot of questions recently regarding Outlook prompting for a username and password whilst using Exchange 2007. There are a few reasons why this would happen and I will try to cover t...
  6. Backup Exchange 2010 Information Store using Windows Backup
    There seems to be quite a lot of confusion around the ability to backup Exchange 2010 using the built in Windows Backup feature. This stems from the omission of this feature prior to Exchange 2007 s...

Cloud Class Webinars

  1. Avoiding Bugs in Microsoft Access
    Alison Balter takes and in-depth look at avoiding bugs in Access. In this webinar you will learn about using the immediate window to debug your applications, invoking the debugger, using breakpoints to troubleshoot, stepping through code, setting the next statement to execute, ...
  2. Top 10 Best New Features in Visio 2010
    Scott Helmers gives live demonstrations of the top 10 new features in Visio 2010. This webinar will teach you how to create compelling diagrams by adding shapes to the page with a single click, linking the shapes in a diagram to data in Excel (or SQL Server, or SharePoint), ...
  3. IT Consultant Business Secrets Revealed
    Michael Munger, Experts Exchange tech pro and IT consultant, pulls back the curtain on his very successful businesses and answers question on every IT consultant and business owner should know about. He shares secrets on what he did to solve the 5 most common problems in IT, ...
  4. Disaster Recovery and Business Continuity
    Quest CTO, Mike Billon, gives an overview of the steps involved in building a dunamic disaster recovery plan. Through case studies and an examination of software/hardware tooles for monitoring and testing, you'll gain a better understandin of where you are, where you want ...
  5. Organize Your Visio Diagrams with Containers and Lists
    Scott Helmers uses cross functional flowcharts, wireframe diagrams, data graphic legends and seating charts to teach you: how to ustilize all three new structured diagram components in Visio 2010, the best practices for organizeing shapes in previous version of Visio, how to organize ...
  6. How to Us Objects, Properties, Events and Methods in Microsoft Access
    Alison Dalter gives an in-depbth look at objects, properties, events and methods in Microsoft Access. In this webinar you will learn about using the object browser, referring to objects, working with properties and methods, working with object variables, understanding the ...

Join the Community

Give a Little. Get a Lot.

Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.

Join the Community

Answers

 

by: davorinPosted on 2003-08-16 at 04:47:02ID: 9165217

/30 block has 4 IP addresses: one is used for network adderess, one for broadcast and two are avaible for interfaces- no spare.
I think the only option is NAT.


 

by: linesplicePosted on 2003-08-16 at 08:06:12ID: 9165656

Well, the strange thing is that these are the addresses I see on the current config of the two routers.  Did my ISP provision more than a /30?  In any event, if we made believe I had more than just 4 available IP's how would I configure the router to route .155?

Currently in the config's:

router 1
...150
...157
...159
...158

router 2
...154
...158
...153
...157

Thanks!

 

by: lrmoorePosted on 2003-08-17 at 13:32:26ID: 9169710

>I want to route one or two of the /30 IP's to an internal interface
You have one /30 subnet between you and your ISP  ...150 --> ..149  <-- this is your gateway ..155=broadcast
You have one /30 subnet between you and RouterB   ...157 --> ..158   ...159=broadcast

There are no available host addresses on either one.
There is no .155 available to route to.

I'll break it down a little more:
Subnet mask /30 255.255.255.252
1.2.3.148 = network ID = not available for host
1.2.3.149 = Host1
1.2.3.150 = Host2
1.2.3.151 = Broadcast = not available for host
1.2.3.152 = network ID
1.2.3.153 = Host1
1.2.3.154 = Host2
1.2.3.155 = Broadcast
1.2.3.156 = network ID
1.2.3.157 = Host1
1.2.3.158 = Host2
1.2.3.159 = Broadcast

You cannot necessarily assume that the ISP has allocated  the .152-.154 subnet to you. It could very well be used with a different customer.

If these do belong to you, and you want to use them on Router B, you would have to configure the Ethernet interface as ..153/30
and add a static route on this router:
ip route 1.2.3.4.152 255.255.255.252 123.456.789.158

That would only give you 1 IP address to play with (.154) as a host address. If that host is a firewall running NAPT, you're good to go..

 

by: linesplicePosted on 2003-08-18 at 06:19:05ID: 9173215

Thank you, lrmoore.
I think that's the missing information I was looking for!

 

by: lrmoorePosted on 2003-08-18 at 07:28:53ID: 9173748

Glad to help!

20120131-EE-VQP-002

3 Ways to Join

30-Day Free Trial

The Experts

98% positive feedback on 31,087 answers since March 2000. angeliii is a Microsoft Most Valuable Professional for his work with MS SQL Server & Develoment.

He has also proven his knowledge of Visual Basic Programming, PHP Scripting and Oracle Databases.

The Experts

97% positive feedback on 10,752 answers since July 2000. lrmoore has more than 18 years experience in the networking industry.

The six-time Mircosoft MVPs specialties include firewalls, virtual private networking, and network management.

Testimonials

"...and excellent source for support... Kind of like having your very own IT dept." Electriciansnet

Testimonials

"I was apprehensive at signing up at first. However... it has already made my life as an IT administrator much easier." JaCrews

Testimonials

"WOW! You guys have great, active, and knowledgeable people on here." moore50

Business Clients

Business Clients

In the Press

"If you’ve got a question... Experts Exchange can supply an answer.”

In the Press

"...an invaluable aid for both IT professionals and those who require tech support."

In the Press

"where IT professionals provide quick answers on just about any topic"

Business Account Plans

Loading Advertisement...