I hva e4 routers, 2 1600s, 2 2500s and 1 2600. When I connect the serial interfaces back to back, configure IP addresses on the inrerfaces, the Serial interfaces do not come up. I thought I had a problem with cabling, so I purchased new DCE/DTE cables but the interfaces still do not come up even if I issue the no shut commands.
I have tried configuring both ends with the clock rate command to no avail. When I do show controllers, I see not connected or there is nothing that comes to indicate which side is the DTE or DCE. I cannot imagine all thes e interfaces are bad.
Here is an output for show controllers on the 2600:
Interface Serial0/0
Hardware is PowerQUICC MPC860
No serial cable attached
idb at 0x80F9C4C8, driver data structure at 0x80F9E06C
SCC Registers:
General [GSMR]=0x2:0x00000030, Protocol-specific [PSMR]=0x8
Events [SCCE]=0x0300, Mask [SCCM]=0x001F, Status [SCCS]=0x03
Transmit on Demand [TODR]=0x0, Data Sync [DSR]=0x7E7E
Interrupt Registers:
But I know ther is a cable attached to derial0 0n the 1600 router.
I see this in the logs of the 1600:
QUICC_ETHER-1-LOSTCARR: Unit 0, lost carrier. Transceiver problem?
%LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0, changed state to up
%LINK-3-UPDOWN: Interface Serial1, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to down
%LINK-3-UPDOWN: Interface Serial1, changed state to down
%LINK-3-UPDOWN: Interface Serial1, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to up
ALl show controllers outputs do not give me usefull information
What am I doing wrong or what am I missing.
Thanks,
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that1guy15 is correct, you need to set the clock rate on the DCE side of the connection. Set a low clock rate like 64 or 128 . . . I don't know what a 1600 serial interface will handle but surely it will handle 64k. Did you set encapsulation to PPP on both sides? HDLC?
Post your config.
Good luck,
SteveJ
Thank you for all your responses. I did something that I thought was strange when the the the started working. I had two serial cables that I connected back to back with DB25s. I saw the interfaces come up. After that I tried my new cbles that have DCE and DTE ends, and the whole thing started working. I did that for all the interfaces that were not working and now I have all my routers connected and working correctly. I ahve no idea why it worked after trying the connections with the DB25s
With the old cables were you able to set the clock rate on both sides? if so then you only had DCE cables set up. Cisco routers automatically recognize if the cable is DCE or DTE and you will get an error when trying to set the clock rate on the DTE side. You can only set the clock rate on the DCE side.
that1guy15,
I think the autosense cable feature may be hardware / IOS / state dependent. I am fairly sure that the old 2621s I used to play with let you set clock when no cable was plugged in (how would it know what you intended to plug in??). . . or when the cable was plugged into the cisco box but not plugged into a a CSU/DSU or a DTE cable.
Steve
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by: cnelissenPosted on 2007-09-04 at 14:28:46ID: 19828657
So you are connecting two routers directly to each other with a serial cable? Meaning, you are not using some sort of Frame Relay or Point to Point connection in between correct?