Trouble routing fast ethernet interfaces between Cisco 2811 and 1841

[rirest]

Hello Guys,

Having trouble routing fast ethernet interfaces between Cisco 2811 and Cisco 1841 routers? I think I checked everything, but may have missed something. This is my lab I'm doing for my class. Please help. Let me know what you need to see.

Thanks

[balaji.bandi]

Can you post the configuration of both the device  - explain what interface you having an issue ?

[rirest]

Hi, balaji bandi

Both my ports on both routers are showing up and down.

1841 config
ISP#sh run
Building configuration...

Current configuration : 911 bytes
!
! Last configuration change at 20:02:05 UTC Sat Nov 30 2019
version 15.1
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname ISP
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
!
dot11 syslog
ip source-route
!
!
!
!
!
ip cef
no ipv6 cef
!
multilink bundle-name authenticated
!
crypto pki token default removal timeout 0
!
!
!
!
license udi pid CISCO1841 sn FTX1129W1CK
!
redundancy
!
!
!
!
!
!
!
!
!
interface FastEthernet0/0
ip address 100.100.100.1 255.255.255.252
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 200.200.200.1 255.255.255.0
duplex auto
speed auto
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
!
ip route 0.0.0.0 0.0.0.0 100.100.100.2
!
!
!
!
!
!
!
control-plane
!
!
!
line con 0
line aux 0
line vty 0 4
login
transport input all
!
scheduler allocate 20000 1000
end

2811 config
R1#sh run
Building configuration...

Current configuration : 1112 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!
logging message-counter syslog
!
no aaa new-model
!
dot11 syslog
ip source-route
!
!
ip cef
!
!
no ipv6 cef
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
voice-card 0
!
!
!
!
!
archive
log config
hidekeys
!
!
!
!
!
!
!
!
!
interface FastEthernet0/0
ip address 100.100.100.2 255.255.255.252
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
duplex auto
speed auto
!
interface Serial0/0/0
no ip address
shutdown
clock rate 2000000
!
interface Serial0/0/1
ip address 10.0.0.1 255.255.255.252
clock rate 64000
!
ip forward-protocol nd
ip route 192.168.10.64 255.255.255.192 10.0.0.2
ip route 192.168.10.192 255.255.255.192 10.0.0.2
ip route 200.200.200.0 255.255.255.0 100.100.100.1
no ip http server
no ip http secure-server
!
!
!
!
!
!
!
!
!
control-plane
!
!
!
!
mgcp fax t38 ecm
!
!
!
!
!
!
line con 0
line aux 0
line vty 0 4
login
!
scheduler allocate 20000 1000
end

[Richard Burts]

When I look at the configs that you posted I see the 1841 with 2 configured FastEthernet interfaces but the 2811 with only 1 configured FastEthernet interface. Is that correct? Can you check the wiring and verify that you are connecting the correct interfaces? As a way of doing that would you connect to the console of the router, disconnect one of the cables, check the log messages to make sure that the correct interface changed state to down?

Would you post the output from both routers to these commands

show ip interface brief

show interface

HTH

Rick

[Georg Pauwen]

Hello,

if you are doing this in Packet Tracer, you need a cross cable (the dotted cable) to connect the routers to each other...

If you are using real routers, you need a cross cable as well (ping 1/3 and 2/6 reversed)...

[rirest]

No, this is my routers I have at home to do my labs for school.

[balaji.bandi]

ok as per your description I understand this is physical devices, then I would suggest checking the physic connection.

[rirest]

Hi,
Have a cross over cable, when you say 1/3 and 2/6 what am I pinging?

[Richard Burts]

1/3 and 2/6 refer to individual pins in the Ethernet connector. You would be pinging 100.100.100.1 from 100.100.100.2 or pinging 100.100.100.2 from 100.100.100.1.

If the output of show ip interface brief (or of show interface or of show ip interface) shows the interface state as up/down it is most likely a problem with the cable used to connect the routers. You are probably using a standard (straight through) Ethernet cable and need to use a cross over cable.

HTH

Rick

[luis_cordova]

Hi @rirest 

Query:

 What connectivity test are you performing? Why do you conclude that the problem is the connection between these two routers?

Regards

[Richard Burts]

I am basing my comments on this statement from the original poster

Both my ports on both routers are showing up and down.

HTH

Rick

[rirest]

Using a crossover between the routers, even tried other crossover in case this one is bad, still not getting anything.
Even swapped ports on routers to see if problem followed. Can it be anything else?
Thanks

[balaji.bandi]

this suspects different problems ( as you mentioned tried different Cross cables ?)

the question here is - where did you get this device from eBay?

another quick test i suggest test is, connect the laptop to the port and see if the port comes up and you able to configure your PC same IP address and able to ping?

Try both routers and confirm device ports come and working as expected?

[rirest]

Hi, 

I used these before with no problems.

I just swapped the ports that go between the routers and still shows protocol down. 

Thanks

[Georg Pauwen]

Hello,

try and set duplex and speed:

duplex full

speed 100