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New Member

CTS is down

I have two LANS which I have connected using 2611 and 1601 cisco routers interfaced by codex modems on each end and a 14.4 k data line.My problem is when I ping my serial interfaces, the suceess rate ranges from 40 to 60 % which to me shows something is not ok. When I checked the interface i.e s1/3 statistics on the 2611 router which I am using to connect to the other router I have noted the following on the last line of the interface statistics:

DCD=up DSR=up DTR=up RTS=up CTS=down

I dont know if the loss of the packets is ralated to the CTS being down or I dont know what causes CTS to be down? The rest of the statistics of the interface is as shown dowm.

Serial1/3 is up, line protocol is up

Hardware is CD2430 in sync mode

Description: Connecting xxxxxxxx

Internet address is 192.168.40.6/24

MTU 1500 bytes, BW 128 Kbit, DLY 20000 usec, rely 245/255, load 9/255

Encapsulation HDLC, loopback not set, keepalive set (10 sec)

Last input 00:00:00, output 00:00:01, output hang 06:53:34

Last clearing of "show interface" counters never

Input queue: 0/75/0 (size/max/drops); Total output drops: 72

Queueing strategy: weighted fair

Output queue: 0/1000/64/70 (size/max total/threshold/drops)

Conversations 0/13/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

5 minute input rate 1000 bits/sec, 4 packets/sec

5 minute output rate 4000 bits/sec, 4 packets/sec

41641 packets input, 2363638 bytes, 0 no buffer

Received 14124 broadcasts, 0 runts, 0 giants, 0 throttles

864379 input errors, 535651 CRC, 0 frame, 0 overrun, 0 ignored, 328726 abort

81934 packets output, 20944585 bytes, 0 underruns

0 output errors, 0 collisions, 35651 interface resets

0 output buffer failures, 0 output buffers swapped out

32 carrier transitions

DCD=up DSR=up DTR=up RTS=up CTS=down

Cisco_2611_IT#

2 REPLIES
Bronze

Re: CTS is down

If your link is full duplex then RTS/CTS should always be up. For half duplex they should toggle between up/down. CTS is raised be the DCE device ie the modem.

Looking at the number of input and CRC errors however, you definately have a physical level problem on this link. Could be a fault cable, electrical interference or a Telco issue.

New Member

Re: CTS is down

yes?how to explain the following :

ybc2sgm#sh int s0/1

Serial0/1 is up, line protocol is up

Hardware is DSCC4 Serial

Description: connected to sgm by satellite

Internet address is 10.4.1.13/30

MTU 1500 bytes, BW 128 Kbit, DLY 20000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation PPP, loopback not set

Keepalive set (10 sec)

LCP Open

Open: IPCP

Last input 00:00:05, output 00:00:05, output hang never

Last clearing of "show interface" counters 1d02h

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: weighted fair

Output queue: 0/1000/64/0 (size/max total/threshold/drops)

Conversations 0/1/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

Available Bandwidth 96 kilobits/sec

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

2393 packets input, 40056 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

6218 packets output, 93582 bytes, 0 underruns

0 output errors, 0 collisions, 949 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

DCD=up DSR=down DTR=up RTS=up CTS=down

the protocol is up,but the DSR=down CTS=down,why? please help me.thanks.

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