Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations Mike Lewis on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Cannot keep interface up

Status
Not open for further replies.

TSupportEngineer

Technical User
Aug 2, 2005
53
US
Hello. I am setting up a lab for CCNA and seem to have a problem keeping serial interfaces up. I have started from the setup utility and enabled IP. I have a 1600 connected to a 2500 via a crossover cable. The 1600 is the DCE with a clockrate set. I will post both configs (they are basic) but even with "no shutdown", the interfaces and protocols stay down. It is probably something stupid, but would appreciate any help. Also, the router asks for User Access Verification and I would like to turn that off. Thanks in advance.


1600 Router

GAD#sho run
Building configuration...

Current configuration:
!
version 11.1
no service udp-small-servers
no service tcp-small-servers
!
hostname GAD
!
enable secret 5 $1$QHC7$MPa9Y87puWBbIVeNGkV3F1
enable password cisco
!
!
interface Ethernet0
no ip address
shutdown
!
interface Serial0
ip address 192.168.15.1 255.255.255.0
no fair-queue
clockrate 56000
!
no ip classless
logging buffered
!
line con 0
password cisco
login
line vty 0 4
password cisco
login
!
end

2500 router
BHM#sho run
Building configuration...

Current configuration:
!
version 11.1
service slave-log
service udp-small-servers
service tcp-small-servers
!
hostname BHM
!
enable secret 5 $1$lq97$ffkDXpNNtsQygyklcYx/C0
enable password cisco
!
!
interface Ethernet0
no ip address
shutdown
no mop enabled
!
interface Serial0
ip address 192.168.15.2 255.255.255.0
!
interface Serial1
ip address 192.168.15.3 255.255.255.0
!
router rip
network 192.168.2.0
network 172.16.0.0
network 192.168.15.0
!
no ip classless
!
!
line con 0
line aux 0
line vty 0 4
password cisco
login
!
end
 
(PS - The User Access Verification shows before the user EXEC mode password is displayed) - TSEngineer.
 

How do you have the serial interfaces connected?
Is GAD connected to the DCE end of the cable?
 
GAD (1600 - DCE) ----- BHM (2500 - DTE) via serial crossover cable. Here is the show interfaces:

GAD (1600)

GAD#sho interfaces
Ethernet0 is administratively down, line protocol is down
Hardware is QUICC Ethernet, address is 0010.7b5a.103a (bia 0010.7b5a.103a)
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, rely 252/255, load 1/255
Encapsulation ARPA, loopback not set, keepalive set (10 sec)
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 01:43:46, output hang never
Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 input packets with dribble condition detected
2 packets output, 367 bytes, 0 underruns
2 output errors, 0 collisions, 1 interface resets
0 babbles, 0 late collision, 0 deferred
2 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Serial0 is down, line protocol is down
Hardware is QUICC Serial
Internet address is 192.168.15.1/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation HDLC, loopback not set, keepalive set (10 sec)
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 216 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=down RTS=down CTS=up
GAD#

BHM (2500)

BHM#sho interfaces
Ethernet0 is administratively down, line protocol is down
Hardware is Lance, address is 0000.0c8d.cece (bia 0000.0c8d.cece)
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, rely 217/255, load 1/255
Encapsulation ARPA, loopback not set, keepalive set (10 sec)
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 01:33:04, output hang never
Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 input packets with dribble condition detected
30 packets output, 1838 bytes, 0 underruns
30 output errors, 0 collisions, 4 interface resets
0 babbles, 0 late collision, 0 deferred
30 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Serial0 is down, line protocol is down
Hardware is HD64570
Internet address is 192.168.15.2/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation HDLC, loopback not set, keepalive set (10 sec)
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/64/0 (size/threshold/drops)
Conversations 0/0 (active/max active)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 194 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=down RTS=down CTS=up
Serial1 is down, line protocol is down
Hardware is HD64570
Internet address is 192.168.15.3/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation HDLC, loopback not set, keepalive set (10 sec)
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/64/0 (size/threshold/drops)
Conversations 0/0 (active/max active)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 169 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=down RTS=down CTS=up
BHM#
 
Configure encapsulation on both sides.

!
interface Serial0/0
ip address 192.168.15.2 255.255.255.0
encapsulation ppp
no ip mroute-cache
!

Serial0/0 is up, line protocol is up
Hardware is PQUICC with Fractional T1 CSU/DSU
Internet address is 192.168.15.2/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
 
Are your interfaces up, up?
Display the config again and post it. You should be able to ping.
 
What type of cable are you using? I am using Rj45s on my T1 Module. If it's a cisco serial cable you my need to specify DTE on the serial interface.
 
I'm using a serial crossover cable w/DCE and DTE labeled ends. The 1600 I have used before and was working, the 2500 I just got recently.
 
I think you'll need to specify DCE or DTE on one of the applicable sides.

Are you interfaces up, up?
 
No, that is the problem, they are down, down. Even when I incorporate "no shutdown" I cannot ping the interface.
 
Got it!
set the clockrate for both sides

clockrate 56000
 
if you do a
"show contollers serial 0" and serial 1 on the other router

do they show dce and dte respectivly?

just make sure that your DCE end is the one youve specified the clockrate on.
 
Yes---post a show contr and show diag. I can tell you issued the "no shut" command, because the interfaces would say they were administratively down, not just down. You have a layer one problem, with either the serial interface on the 2500 (UNLIKELY), OR THE CABLE (MOST LIKELY). i HAVE GOTTEN INTO THE HABIT OF PUTTING THE CLOCKRATE (damn caps button) on both DTE and DCE interfaces myself. It doesn't cause any problems, and I don't have to pay attention to which is which. Besides, line protocol is layer two. Your problem is definitely layer one related. Good luck.

Tim
 
pconrad, Ru55ell, plshlpme, and fartingfrog: Thanks all, I never remember having to set timing on both ends of the connection, but I did and changed the cable. Still had the problem until I noticed the encapsulation was different on both interfaces (ppp and hdlc). Changed both to hdlc (for now), and I'm pinging like nobody's business. Thanks for all the help! TSEngineer
 
Little late to the party on this one but just wanted to state that A) You should'nt have needed to configure PPP as it was already configured with an encapsulation (HDLC by default) and B) If you had to set the clock rate on both ends it means you set it on the first end wrong. The clock rate only needs to be set on the DCE side (but as fartingfrog mentioned, doesn't hurt to do both).

After seeing your config and int status the next thing to look at would've been "show controller serial 0 | i V.35" the output will show you which side is DCE and which is DTE.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top