Interface S0, CTS=down

jeff.yau · ‎10-23-2003

Hi,

I have come across error after I change a new router.

Now I can ping and telnet the router, but two network communications are down.

When I telnet to the router and type sh int, it shows that CTS=down and a lot of input error appear, as below:

ASM-SH#sh int s0

Serial0 is up, line protocol is up

Hardware is PowerQUICC Serial

Description: 256 Frame-Relay line SH to STJ

Internet address is 10.206.2.2/24

MTU 1500 bytes, BW 256 Kbit, DLY 20000 usec,

reliability 181/255, txload 1/255, rxload 1/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

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

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 234

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 1000 bits/sec, 2 packets/sec

5 minute output rate 1000 bits/sec, 2 packets/sec

109306 packets input, 14420879 bytes, 0 no buffer

Received 5711 broadcasts, 7 runts, 0 giants, 0 throttles

260059 input errors, 6787 CRC, 252924 frame, 0 overrun, 0 ignored, 348 abort

238717 packets output, 26842280 bytes, 0 underruns 0 output errors, 0 collisions, 34 interface resets 0 output buffer failures, 0 output buffers swapped out 0 carrier transitions

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

Would anybody tell me what is the source of error? I have changed a new router and V.35 cable but nothing improved.

Any comment will be appreciated, thank you!

aslam · ‎10-23-2003

Check out this link

http://www.cisco.com/univercd/cc/td/doc/cisintwk/itg_v1/tr1915.htm

jolmo · ‎10-23-2003

CTS = Clear to send.

This signal is output by the DCE to acknowledge RTS and to indicate that it is ready for data transmission.

So if your serial interface is acting as DTE, there's a problem with the CSU/DSU or modem.

HTH

jeff.yau · ‎10-26-2003

After I change the modem, the CTS shows "up" status again.

However, there was still a lot of input, CRC and frame error on the serial interface, as below: