Routing help with CCNA Lab

[telnettech]

I am working on my CCNA with no help from any formal training class and no one in my whole company is CCNA certified or even attempted this. I am using the Sybex book from Lammle and also "Test Out" PC program to accomplish this. I have read the IP routing and Routing protocol chapters of the book numberous times and have reached a point that i cant figure this problem out.

I have a Lab setup that I bought off Ebay that has 3 routers (2610) and 2 switches (1900 series). This is what I have seen many people on this site recommend to have to practice with.

My Router "A" is programmed as following:

LAB_Top#sh ip int brief
Interface IP-Address OK? Method Status Prot
ocol
Ethernet0/0 192.168.5.1 YES NVRAM up up

Serial0/0 192.168.6.1 YES NVRAM up up

Also the IP Protocol is as follows:

LAB_Top#sh ip proto
Routing Protocol is "rip"
Sending updates every 30 seconds, next due in 11 seconds
Invalid after 180 seconds, hold down 180, flushed after 240
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Redistributing: rip
Default version control: send version 1, receive any version
Interface Send Recv Triggered RIP Key-chain
Ethernet0/0 1 1 2
Serial0/0 1 1 2
Automatic network summarization is in effect
Maximum path: 4
Routing for Networks:
192.168.5.0
192.168.6.0
Routing Information Sources:
Gateway Distance Last Update
192.168.6.2 120 00:05:43
Distance: (default is 120)

The following IP routes are in the list:

Gateway of last resort is not set

C 192.168.5.0/24 is directly connected, Ethernet0/0
C 192.168.6.0/24 is directly connected, Serial0/0
R 192.168.1.0/24 [120/1] via 192.168.6.2, 00:00:00, Serial0/0

My other Router "B" has the following setup

LABMiddle#sh ip int brief
Interface IP-Address OK? Method Status Prot
ocol
Ethernet0/0 192.168.1.180 YES NVRAM up up

Serial0/0 192.168.6.2 YES NVRAM up up

Serial0/1 unassigned YES NVRAM administratively down down

Routing Protocol is "rip"
Sending updates every 30 seconds, next due in 18 seconds
Invalid after 180 seconds, hold down 180, flushed after 240
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Redistributing: rip
Default version control: send version 1, receive any version
Interface Send Recv Triggered RIP Key-chain
Serial0/0 1 1 2
Automatic network summarization is in effect
Maximum path: 4
Routing for Networks:
192.168.1.0
192.168.6.0
Passive Interface(s):
Ethernet0/0
Routing Information Sources:
Gateway Distance Last Update
192.168.6.1 120 00:00:24
Distance: (default is 120)

And the routing is as follows:

LABMiddle#sh ip rout

Gateway of last resort is not set

R 192.168.5.0/24 [120/1] via 192.168.6.1, 00:00:09, Serial0/0
C 192.168.6.0/24 is directly connected, Serial0/0
C 192.168.1.0/24 is directly connected, Ethernet0/0


The 192.168.1.0 is the company network and when i try to ping it from Router "A" I am not to get a response back from it. Also 192.168.5.0 on Router "B" is a 1900 series switch that I can ping to it from Router "B" but the pc connected to this switch need to be able to go out to the 192.168.1.0 network so that it can get an ip address from the DHCP server.

Can anyone help figure out what i am doing wrong as I am not able to figure it out thru the book's help.

Brian

To error is human.....if the machine doesnt work, then KICK IT !!!!!!!!!!!!!

 

[CiscoGuy33]

telnettech,

You said - " I have a Lab setup that I bought off Ebay that has 3 routers (2610) and 2 switches (1900 series). This is what I have seen many people on this site recommend to have to practice with."

Yes, 3 routers and 2 switches are what most call for here but NOT the 1900s anymore - they are no longer supported on the CCNA exam. For at least the past year we have been calling for 2950s or at the least 2924s - the CAT IOS on those 1900s are not close to what you will see or need to know on the CCNA!!

As for the DHCP - when I ran a setup like this across a "test" network of 6 different networks we had to use a "helper" command to forward the DHCP broadcasts (routers stop brodcasts) - I will need to look up the command and post for you!

Hope this helps!



E.A. Broda
CCNA, CCDA, CCAI, Network +

 

[telnettech]

anybody have any suggestions?

Brian

To error is human.....if the machine doesnt work, then KICK IT !!!!!!!!!!!!!

 

[CiscoGuy33]

Brian,

I think this will work, tell the routers where the DHCP server is and then it will allow the DHCP broadcasts (UDP)

Command:
ip helper-address

Mode:
Router(config-if)#

Syntax:
ip helper-address address

no ip helper-address address

Syntax Description:

address Destination broadcast or host address to be used when forwarding UDP broadcasts. There can be more than one helper address per interface.

Command Description:
To have the Cisco IOS software forward User Datagram Protocol (UDP) broadcasts, including BOOTP, received on an interface, use the ip helper-address interface configuration command. To disable the forwarding of broadcast packets to specific addresses, use the no form of this command.

Example:
Router(config-if)#ip helper-address 121.24.43.2

Hope this helps!




E.A. Broda
CCNA, CCDA, CCAI, Network +

 

[burtsbees]

From Router A...
ping 192.168.1.180
this fails?

Burt

 

[brianinms]

On the 1.x network what is your default gateway? It sounds like your local network doesn't know to send requests for the 5.x and 6.x network to 1.180.

 

[telnettech]

Burtsbees,

Yes I am able to ping the 192.168.1.180 address and as you see, the routing is there to point to the 1.x to go out the 192.168.6.2 on Router A. I thought Router B would see the incoming and look at the destination address and realize that it should send it out the 192.168.1.180 address on Eth0 to reach the 1.x network.

BrianinMS,

The default gateway for the 1.x network is 1.1. Again on Router A there is a route that states that 192.168.6.2 is the path to the 1.x network. the 192.168.6.2 connects to the S0 interface and connects to Router B. If I read Todd's book right, router B should look at the destination address and send it to the 1.x network. The DHCP is at 192.168.1.20.

Brian

To error is human.....if the machine doesnt work, then KICK IT !!!!!!!!!!!!!

 

[brianinms]

You need a route on router 1.1 that sends traffic for 5.x and 6.x to 1.180

 

[CiscoGuy33]

Brian,

You are trying to send a broadcast from one subnet 192.168.1.0 to 192.168.6.0

DHCP sends UDP packets as a broadcast and routers do not forward broadcasts as a rule. Routers define broadcast domains!

We had this same trouble when we setup a Microsoft DHCP lab in a classroom - the Windows server doing DHCP was on one subnet and the Windows workstations were on 5 other different subnets. To get the routers to forward the broadcasts we had to use the IP helper command I listed above.

Unless I am missing something - this is a broadcast issue!


E.A. Broda
CCNA, CCDA, CCAI, Network +

 

[burtsbees]

Gene's right. I missed that...I was concentrating on this statement..."I am not to get a response back from it"...does that mean that you cannot or should not?
For forwarding broadcasts, you do need ip helper-address or ip forward-protocol...

http://cisco.com/univercd/cc/td/doc/product/software/ios113ed/cs/csprtn1/csipadr.htm#xtocid2736518

http://cisco.com/univercd/cc/td/doc/product/software/ios113ed/cs/csprtn1/csipadr.htm#xtocid2736522

http://cisco.com/univercd/cc/td/doc/product/software/ios113ed/cs/csprtn1/csipadr.htm

Burt

 

[CiscoGuy33]

Thanks Burt - I thought I was missing something!!! ;-)

E.A. Broda
CCNA, CCDA, CCAI, Network +