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Cisco 1841 FastEthernet0 is up, line protocol is down.

JOSIAH BOZIAH
Level 1
Level 1

I have a Fortigate Fortiwifi 60E and  3  Cisco 1841 Routers  connected.  LAN PORT 2 on Fortigate is connected to Cisco Router1 F0/0

From Cisco Router1 1841 F0/1 is connected to another Cisco 1841 Router2 F0/0 ,  F0/1 on that router2 is connected to another Cisco Router3 F0/1. F0/0 on Router3  is connected to Fortigate Fortiwifi 60E  LANPORT3. F0/1 on Router1  connected  to F0/0 Router2 shows link light just fine.      I receive no links light On Router2 F0/1 and Router3 F0/1 , when i issue the command show interface Fastethernet 0/1 on Both Router2 and Router3 it shows   FastEthernet0/1 is up, line protocol is down . But no link light from F0/1 on Router2 to F0/1 on Router3.I checked the  duplex and speed of both interfaces and they are both on auto. Not sure whats happening here.  When i plug another device like switch the link lights come on,also link  is on on F0/0 on Router3 connected to Fortigate Fortiwifi 60E . link light is on from Router1 F0/1 to Router2 F0/0, just dont know why its not on from Router2 F0/1 to Router3 F0/1.... i am missing some setting between Router2 and Router 3 

8 Replies 8

use the cable connect R1-R2 in connection between R2-R3 and check 

Nope did not work.

R-R cable is not working between two other routers?

Please share

Show ip interface 

Show interface 

Complete output

Hi

 Make sure you dont have disabled mdix. You are probably using straitforward cable right? 

Device(config-if)# mdix auto

i tried the mdix auto on the interface but received unrecognized command or invalid input.

If yiu can not change the mdix config, then you need to use cross over cable as router to router must be cross over. 

Router to switch is straitforward cable and thats why when you plugged a switch instead router,  the link came up. 

Hello


@JOSIAH BOZIAH wrote:

 when i issue the command show interface Fastethernet 0/1 on Both Router2 and Router3 it shows   FastEthernet0/1 is up, line protocol is down . But no link light from F0/1 on Router2 to F0/1 on Router3.I checked the  duplex and speed of both interfaces and they are both on auto. Not sure whats happening here.  When i plug another device like switch the link lights come on


You will most probably require a cross-over cable  between the RTRs if the ports do not support MDIX which it sounds like they don’t


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Kind Regards
Paul

i will buy a crossover cable tomorrow....will update...

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