Configuring Cisco Routers

Posted on 2008-06-23
Last Modified: 2011-10-19
I have 2 routers and 4 switches

Router1 has 3 interfaces , 2 interfaces connected to 2 switches (separate subnets ) and one interface is connected to Router2
Router2 has 3 interfaces 2 interfaces connected to 2 switches (separate subnets ) and one interface is connected to Route1
These routers and swicthes are all in the same building, different floors.
I need help to configure router1 and router2 to get all hosts in all networks able to talk to each other.
I also want both routers to be DHCP servers.
I need an expert to write to me the configuration needed and explain to  me if it's a Must or Optional, for instance:
Interfaces configuration ( is it a Must or optional)?
Do I need default route or static route? or should I use Dynamic Routing?
If I need  to advertize the network (if I will have to) ex: ROuter1(config)# Network
If I need to config default router ex:ROuter1(config)# Default router


Question by:jskfan
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Expert Comment

by:Andres Perales
ID: 21846370
What are the specific models of  your devices...

Author Comment

ID: 21846759
2900 series
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Expert Comment

by:Andres Perales
ID: 21847819
So you have 2900 series switches?

1st of all you really only need one router...this router would take care of all of your internal routing...this would be connected to what you would call a core switch.  The connection between this router and switch should be trunked.

then you would connect all of the other switches to this core switch and trunk those ports as well...trunk ports allow those devices to pass all traffic that it knows about to the next device.

You can then configure your router and core switch to do vlans, these are virtual lans...and be propogated all the way down to your clients...something like the image below...

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Author Comment

ID: 21849537
in this case, I will have to configure VLANs in the core switch.
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Expert Comment

by:Andres Perales
ID: 21849586
yes you will need to configure vlans in the core switch and they should propogate down to the floor switches at which point you configure each port to a different vlan if you need too...

Author Comment

ID: 21849733
if I have a second  router available , can't I just go ahead and use it.
in this case, since the 2 routers will be connected directely, do I need to configure just the interfaces on both routers and the routing table will be built automatically? or there is morte than configuring just interfaces?
LVL 17

Accepted Solution

Andres Perales earned 500 total points
ID: 21857117
Where would you like to put that second router, what we have done in the past is copy the configuration of the active router to the second router and use it as a standby, make sure it is exactly the same...also can be used when it is time to upgrade IOS you would use the standby one as your updated router and then all you have to do is unplug active router and plug in the updated router, then update the older router to maintain the same configurations...

If you want to get fancy dancy you can setup HSRP...lots of documentation on the Cisco website for HSRP

Author Comment

ID: 21858815
the point in setting up this is to learn the Cisco routers configuration:
-In case 2 routers are connected directly through their ethernet interface or serial interface, all needed is to go to each router interface and set up its IP address then the Hosts from both networks will start talking to each other. Correct?
- default route ex: IP route  I can use it just in case I have 3 routers lined up, then I will configure this default route in the routers that are located at both ends. Correct?
- static route ex: IP route it is like default gateway , telling it send packets to network through router interface
In this case what is the difference between using the IP route command and using ip default-network command or ip default-gateway command?
-we advertize network only if we use a routing protocol such as RIP. correct
 routerA(config)#router RIP
Correct?  in this case do we still need to configure IP address on the interfaces of routers?

Thanks a lot!

Author Comment

ID: 21874659
amy updates???

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