03-31-2011 07:45 AM - edited 03-06-2019 04:22 PM
I can't seem to get any of my serial connections to ping. I have three routers. One of the routers has multiple serial interfaces that branch out to the others. I went through all steps in my CCNA workbook, following everything to a T, but still nothing pings. (Protocol down on everything) I configured the clock rate on the two DCE routers. (clock rate 64000) - still nothing. Any ideas? These routers are 2600s two on outside running 12.4. The one in the middle 12.3 IOS.
Lab_A#sh ip int brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 172.168.10.1 YES NVRAM up down
Serial0/0 172.16.20.1 YES NVRAM up down
Lab_B>sh ip int brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 unassigned YES NVRAM up down
Serial1/0 172.16.20.2 YES NVRAM up down
Serial1/1 172.16.30.1 YES NVRAM up down
Serial1/2 unassigned YES NVRAM administratively down down
Serial1/3 unassigned YES NVRAM administratively down down
Lab_C#sh ip int brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 172.16.40.1 YES NVRAM up down
Serial0/0 172.16.30.2 YES NVRAM up down
03-31-2011 08:06 AM
sounds strange, first point would be to ensure the DTE router clocking is being received correctly.
do a: show controllers serial x/x for the three routers and post the results pls.
03-31-2011 08:18 AM
03-31-2011 08:13 AM
what cables are you using?DCE DTE?
03-31-2011 08:23 AM
The cables are both labeled on one side DTE, and on the other side they are labeled DCE.
Lab_B or the middle router has the two DTE connections. Lab_A and Lab_C ,or my two outside routers, have the DCE side of the connections. They are the routers I have added the clocking to.
03-31-2011 08:27 AM
Can you post the configs for all the routers, that would help to see what the issue may be.
Mike
03-31-2011 08:38 AM
03-31-2011 11:38 AM
i looked through the files. nothing stands out that could be obviously wrong. Then again i'm a novice, did anyone pick up anything when looking tru the config files?
03-31-2011 04:54 PM
can you post some traceroutes as well??
03-31-2011 06:43 PM
Here you go.....Lab A - Lab B - Lab C. I couldnt understand why you were giving your interface an 172 address and the frame relay portion a 10 address, this might be valid but I have never seen it before (and I have seen very little frame relay...but wanted this challange).
Your pings wont work, but I will leave that for you towork on now
Good luck
Jimmy
The config below work, its staying up/up.
Current configuration : 191 bytes
!
interface Serial0/0
ip address 172.16.20.1 255.255.255.0
encapsulation frame-relay
serial restart-delay 0
clock rate 2016000
no frame-relay inverse-arp
frame-relay intf-type dce
end
Lab_A#sh ip int br
Interface IP-Address OK? Method Status Protocol
Serial0/0 172.16.20.1 YES manual up up
Lab_B#sh run int s0/0
Building configuration...
Current configuration : 116 bytes
!
interface Serial0/0
ip address 172.16.20.2 255.255.255.0
encapsulation frame-relay
serial restart-delay 0
end
Lab_B#sh ip int br
Interface IP-Address OK? Method Status Protocol
Serial0/0 172.16.20.2 YES manual up up
04-04-2011 03:31 PM
I tried your fix of changing the clock rate to it's highest setting and it didn't work. It seems that you didn't even attempt to fix the issue but instead set up your own network using my ip addresses. This does not help. If you have a more specific idea of what changes to make please advise.
04-04-2011 06:35 PM
Changing the clockrate alone wont help. I took your configs, put them into devices, cabled, and watch the line protocol go up/down just as you said. I then looked over the configs, saw some items I didnt understand or agree with. I also used the debug command (the first time I ran this I saw no LMI events, so I knew where to start looking). I just posted the relevant parts of the config, hope it helped.
04-04-2011 06:44 PM
Could you be a little more specific? What commands do I type in the prompt? Thanks.
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