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New Member

DSR & CTS down

Hi all while executing Show int command on one of our remote site , seems Data Set Ready and Clear To Send are on down state , as shown below.......

Serial0/1/0 is up, line protocol is up

  Hardware is GT96K Serial

  Backup interface Dialer1, failure delay 0 sec, secondary disable delay 60 sec,

  kickin load not set, kickout load not set

  MTU 1500 bytes, BW 64 Kbit/sec, DLY 20000 usec,

     reliability 255/255, txload 15/255, rxload 7/255

  Encapsulation PPP, LCP Open, multilink Open

  Link is a member of Multilink bundle Multilink1, 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 1w4d

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

  Queueing strategy: fifo

  Output queue: 0/40 (size/max)

  5 minute input rate 2000 bits/sec, 3 packets/sec

  5 minute output rate 4000 bits/sec, 7 packets/sec

     4797364 packets input, 390759527 bytes, 0 no buffer

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

     16 input errors, 16 CRC, 2 frame, 0 overrun, 0 ignored, 4 abort

     2951233 packets output, 200799167 bytes, 0 underruns

     0 output errors, 0 collisions, 1 interface resets

     0 unknown protocol drops

     0 output buffer failures, 0 output buffers swapped out

     0 carrier transitions

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

what may be the causes for this , as remote site doen't have any connectivity issues .

Thanks & Regards,


Hall of Fame Super Silver

DSR & CTS down


There might be several things that could explain what you are seeing and the lack of impact.

- I see that this interface is a member of a multilink  bundle. It is possible that the other members of the multilink are carrying traffic and that is why the remote site is not experiencing connectivity issues.

- we do not know what is physically connected there and whether that device generates DSR or CTS or not. Is it possible that the device does not generate these signals and works normally without them?

- we do not know how the interface is configured and whether there might be something in the config that could help to explain what is going on. Perhaps you can post the config of the interface.

- the fact that it shows line is up and line protocol is up seem to indicate that the interface is operating ok. If you do a show interface, wait a bit, then do another show interface are the counters of packets going in and going out increasing?



New Member

DSR & CTS down

Hi Rick .....

-well . actually its a DTE site and we use V.35 interface standard and use Smart Serial .

We have DCE which is a Telco Operator .

-Its a part of Multilink bundle . But its other member is none other than a virtual  Multilink interface .

-Packets are  flowing as usual.

-Actually if a DTE is connected to DCE and DCE is working fine . then both DSR and CTS must be Up ??

- these are our serilal and multilink conf templates :

interface Serial0/1/0

backup delay 0 60

backup interface Dialer1

no ip address

encapsulation ppp

no fair-queue

ppp multilink

ppp multilink group 1

crypto map **

interface Multilink1

ip address *****************

no ip redirects

no ip proxy-arp

ip ospf authentication message-digest

ip ospf message-digest-key 156 md5 7 0337594A250A77795C2C49412714

ppp multilink

ppp multilink interleave

ppp multilink group 1

ppp multilink fragment delay 10

crypto map ***************

max-reserved-bandwidth 90

service-policy output QOS


- Rick one more thing we have around 190 remote sites  , and only this site shows this thing interesting !!

- If any issue with V.35 cable , will this error occur ???

Thanks & Regards,


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