Serial interface up line protocol down

[bsludick]

Hope someone can help. I am setting up a lab with three Cisco 2500 routers.I am using DCE DTE crossover cables between the routers. On one link I am getting Serial interface up down. I have checked the keep alive settings are both interfaces are set to 10 sec and encapsulation settings are both set to HDLC. I have the clock rate configured on the DCE end (whch is where I get the up down)and I have changed the crossover cable and still no joy. Any ideas?

 

[chipk]

Post the "show interface" from both sides.

 

[bsludick]

Thanks hope this helps.....link is between router 1 and router 3

Router1#sh int serial 1
Serial1 is up, line protocol is down
Hardware is HD64570
Description: Link to Router 3
Internet address is 10.1.2.2/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input never, output 00:00:07, 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 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
89 packets output, 2819 bytes, 0 underruns
0 output errors, 0 collisions, 31 interface resets
0 output buffer failures, 0 output buffers swapped out
106 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
Router1#
***********************************************************
router3#
router3#sh int serial 1
Serial1 is up, line protocol is up
Hardware is HD64570
Description: serial link to router 1
Internet address is 10.1.2.3/24
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 00:00:03, output 00:00:04, 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: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/3/256 (active/max active/max total)
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
123 packets input, 3567 bytes, 0 no buffer
Received 123 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
293 packets output, 42809 bytes, 0 underruns
0 output errors, 0 collisions, 77 interface resets
0 output buffer failures, 0 output buffers swapped out
88 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
router3#

 

[namesrhard2pick]

What do you see if you do a show contollers serial X (X being the serial interface you configured the clockrate). You should see DCE cable, clockrate XXXXXX

 

[burtsbees]

Post a sh run
Also, do a clear counters

Burt

 

[dtrtel]

Sounds like a flaky serial port or connector wire or pin on the receive path to the router reporting line protocal down. The interface up just means it's not shutdown and it's trying to sync up.

There isn't much you can screw up with a lab-based cisco HDLC link.

You mentioned three routers, if all are connecting via serial port HDLC, like R1-R2-R3, troubleshoot the hardware by testing the other connection permutations: R1-R3-R2, or R2-R1-R3. If the problem stays on the same router port, it's got a bad port.

--jeff

http://linkedin.com/in/JeffLynch

 

[burtsbees]

Well, I doubt that...
he should still post a sh run from all 3 routers, or at least a sh int from the serial interface of R2 connecting the the up/down from R1.

Burt

 

[dtrtel]

Agree, config info always helps. But think about it, Burt. We're only talking about an L2 cisco HDLC sync issue. If he just rips out any attempts at modifying the hdlc parms, which I doubt there are any at this point, the only thing left is L1/Phy. They're not integrated CSU/DSU ports, he's using a DCE-DTE cable connection.

--jeff

http://linkedin.com/in/JeffLynch

 

[chipk]

I'm thinking physical layer problem as well.

 

[lerdalt]

Out of curiosity, you might want to try changing to ppp encapsulation. Also, judging by the sh int outputs, looks like there might be a difference in IOS version. Not that it should make a difference, but it might make things a little easier.

 

[burtsbees]

Well, the physical side is up, and line protocol is down. That's one, anyway---we still need the in-between router outputs...

Burt

 

[chipk]

Burt, are you saying a cable problem can't cause up/down status on an interface?

 

[t0mm0]

bsludick , what happened when you followed namesrhard2pick suggestion?

What do you see if you do a show contollers serial X (X being the serial interface you configured the clockrate). You should see DCE cable, clockrate XXXXXX


Also do the logs of R1 outline anything??

 

[burtsbees]

No, definitely not, chipk. I know line protocol down could very well be a cable problem I'm going on the fact that he said he has R2 to R3 working, and he took that cable from the working one and put it on the non-working one. I realize it could still be a bent pin on the card, and of course to troubleshoot physical problem, you always (well, if you can) take a known working card/cable and put it into the router in question, or take a known good router and put the serial card/cable in it. Once this is done with no luck, then we can look at other things...configs, ping outputs, etc. Of course we still need a sh run and a positive ID on his topology---judging from the IP addresses on the interfaces, it looks as if int s1, R1 is connected to int s1, R3...wonder where R2 fits in the picture. At first, I thought he was showing one end to the other (and it's still possible he is, in which case the IP addressing is wrong), like R1-----R2-----R3

Burt

 

[kajo]

perhaps he has it more of a triangle.... R1-----R3
\ /
\ /
R2

 

[bsludick]

Hi Guys, here is the configs of Router 1 and 3. Yes I do have it in a triangle with Router 1 at the top. It is the link from Router 1 to Router 3 that is giving me the problems.

Router1#
Router1#sh ip int brief
Interface IP-Address OK? Method Status Protocol
BRI0 unassigned YES NVRAM administratively down down
BRI0:1 unassigned YES unset administratively down down
BRI0:2 unassigned YES unset administratively down down
Ethernet0 192.168.0.20 YES NVRAM up up
Loopback0 10.1.10.2 YES NVRAM up up
Serial0 10.1.1.2 YES NVRAM up up
Serial1 10.1.2.2 YES NVRAM up down
Router1#
-----------------------------
Router1#sh run
Building configuration...

Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router1
!
enable password cisco
!
ip subnet-zero
ip dhcp excluded-address 192.168.0.1 192.168.0.101
!
ip dhcp pool lab
network 192.168.0.0 255.255.255.0
default-router 192.168.0.1
dns-server 192.168.0.1
lease infinite
!
!
!
!
interface Loopback0
ip address 10.1.10.2 255.255.255.0
no ip directed-broadcast
!
interface Ethernet0
ip address 192.168.0.20 255.255.255.0
no ip directed-broadcast
!
interface Serial0
description serial link to router 2
ip address 10.1.1.2 255.255.255.0
no ip directed-broadcast
no ip mroute-cache
no fair-queue
clockrate 56000
!
interface Serial1
description Link to Router 3
ip address 10.1.2.2 255.255.255.0
no ip directed-broadcast
no fair-queue
clockrate 56000
!
interface BRI0
no ip address
no ip directed-broadcast
shutdown
!
ip classless
no ip http server
!
!
banner motd ^C Welcome to the Cisco test lab - router1 ^C
!
line con 0
password cisco
login
transport input none
line aux 0
password cisco
login
line vty 0 1
password cisco
login
line vty 2 4
login
!
end

Router1#
-------------------------
Router1#
Router1#sh controllers serial 1
HD unit 1, idb = 0x16CEC8, driver structure at 0x1723B8
buffer size 1524 HD unit 1, V.35 DCE cable, clockrate 56000
cpb = 0x63, eda = 0x2940, cda = 0x2800
RX ring with 16 entries at 0x632800
00 bd_ptr=0x2800 pak=0x175954 ds=0x63C60C status=80 pak_size=0
01 bd_ptr=0x2814 pak=0x175718 ds=0x63BF50 status=80 pak_size=0
02 bd_ptr=0x2828 pak=0x1754DC ds=0x63B894 status=80 pak_size=0
03 bd_ptr=0x283C pak=0x1752A0 ds=0x63B1D8 status=80 pak_size=0
04 bd_ptr=0x2850 pak=0x175064 ds=0x63AB1C status=80 pak_size=0
05 bd_ptr=0x2864 pak=0x174E28 ds=0x63A460 status=80 pak_size=0
06 bd_ptr=0x2878 pak=0x174BEC ds=0x639DA4 status=80 pak_size=0
07 bd_ptr=0x288C pak=0x1749B0 ds=0x6396E8 status=80 pak_size=0
08 bd_ptr=0x28A0 pak=0x174774 ds=0x63902C status=80 pak_size=0
09 bd_ptr=0x28B4 pak=0x174538 ds=0x638970 status=80 pak_size=0
10 bd_ptr=0x28C8 pak=0x1742FC ds=0x6382B4 status=80 pak_size=0
11 bd_ptr=0x28DC pak=0x1740C0 ds=0x637BF8 status=80 pak_size=0
12 bd_ptr=0x28F0 pak=0x173E84 ds=0x63753C status=80 pak_size=0
13 bd_ptr=0x2904 pak=0x173C48 ds=0x636E80 status=80 pak_size=0
14 bd_ptr=0x2918 pak=0x173A0C ds=0x6367C4 status=80 pak_size=0
15 bd_ptr=0x292C pak=0x1737D0 ds=0x636108 status=80 pak_size=0
16 bd_ptr=0x2940 pak=0x173594 ds=0x635A4C status=80 pak_size=0
cpb = 0x63, eda = 0x3014, cda = 0x3014
TX ring with 4 entries at 0x633000
00 bd_ptr=0x3000 pak=0x000000 ds=0x6329E4 status=80 pak_size=22
01 bd_ptr=0x3014 pak=0x000000 ds=0x000000 status=80 pak_size=0
02 bd_ptr=0x3028 pak=0x000000 ds=0x000000 status=80 pak_size=0
03 bd_ptr=0x303C pak=0x000000 ds=0x000000 status=80 pak_size=0
04 bd_ptr=0x3050 pak=0x000000 ds=0x000000 status=80 pak_size=0
0 missed datagrams, 0 overruns
0 bad datagram encapsulations, 0 memory errors
0 transmitter underruns
0 residual bit errors

Router1#
---------------------------------

router3#
router3#sh ip int brief
Interface IP-Address OK? Method Status Protocol
Ethernet0 192.168.0.22 YES NVRAM up up
Serial0 10.1.3.3 YES manual up up
Serial1 10.1.2.3 YES NVRAM up up
router3#
router3#
--------------------------------

router3#sh run
Building configuration...

Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname router3
!
enable secret 5 $1$VtbO$CsNywhxYwKoJGQ7OT8oc2/
enable password copper01
!
ip subnet-zero
no ip routing
!
!
!
interface Ethernet0
ip address 192.168.0.22 255.255.255.0
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
!
interface Serial0
description serial link to Router 2
ip address 10.1.3.3 255.255.255.0
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
!
interface Serial1
description serial link to router 1
ip address 10.1.2.3 255.255.255.0
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
!
ip classless
!
!
line con 0
logging synchronous
transport input none
line aux 0
line vty 0 4
password cisco
login
!
end

router3#
-----------------------------

router3#sh controllers serial 1
HD unit 1, idb = 0xD5C50, driver structure at 0xDB0D8
buffer size 1524 HD unit 1, V.35 DTE cable
cpb = 0x82, eda = 0x3000, cda = 0x3014
RX ring with 16 entries at 0x823000
00 bd_ptr=0x3000 pak=0x0DD558 ds=0x82A5A4 status=80 pak_size=22
01 bd_ptr=0x3014 pak=0x0DE578 ds=0x82DB84 status=80 pak_size=0
02 bd_ptr=0x3028 pak=0x0DDD68 ds=0x82C094 status=80 pak_size=0
03 bd_ptr=0x303C pak=0x0DE374 ds=0x82D4C8 status=80 pak_size=0
04 bd_ptr=0x3050 pak=0x0DDB64 ds=0x82B9D8 status=80 pak_size=0
05 bd_ptr=0x3064 pak=0x0DD960 ds=0x82B31C status=80 pak_size=0
06 bd_ptr=0x3078 pak=0x0DD75C ds=0x82AC60 status=80 pak_size=0
07 bd_ptr=0x308C pak=0x0DD354 ds=0x829EE8 status=80 pak_size=0
08 bd_ptr=0x30A0 pak=0x0DD150 ds=0x82982C status=80 pak_size=0
09 bd_ptr=0x30B4 pak=0x0DCF4C ds=0x829170 status=80 pak_size=0
10 bd_ptr=0x30C8 pak=0x0DCD48 ds=0x828AB4 status=80 pak_size=0
11 bd_ptr=0x30DC pak=0x0DCB44 ds=0x8283F8 status=80 pak_size=0
12 bd_ptr=0x30F0 pak=0x0DC940 ds=0x827D3C status=80 pak_size=0
13 bd_ptr=0x3104 pak=0x0DC73C ds=0x827680 status=80 pak_size=0
14 bd_ptr=0x3118 pak=0x0DC538 ds=0x826FC4 status=80 pak_size=0
15 bd_ptr=0x312C pak=0x0DC334 ds=0x826908 status=80 pak_size=0
16 bd_ptr=0x3140 pak=0x0DC130 ds=0x82624C status=80 pak_size=0
cpb = 0x82, eda = 0x3800, cda = 0x3800
TX ring with 1 entries at 0x823800
00 bd_ptr=0x3800 pak=0x000000 ds=0x830D08 status=80 pak_size=22
01 bd_ptr=0x3814 pak=0x000000 ds=0x846408 status=80 pak_size=292
0 missed datagrams, 0 overruns
0 bad datagram encapsulations, 0 memory errors
0 transmitter underruns
0 residual bit errors
---------------------------------------

 

[bsludick]

Hi Again

The layout is something like this
R1
/\
R2-R3

 

[chipk]

I wonder if the framing or line code is wrong in one of the controller configs? I don't see that in any of the output. Usually this would be determined by your provider, but since you're just doing a point-to-point with a crossover, I wonder if that's the problem...

 

[jneiberger]

Take the working cable from the R1-R2 connection and move it to the R1-R3 connection and see if it comes up. This just sounds like a bad cable or bad interface to me.

 

[dtrtel]

As jneiberber says, yes.

You have these known-good scenarios:

R1(s1)clock ----- R2(sX)
R3(s0) ----- R2(sY) (who clocks this?)

So you may have a bad serial port (you proved cables good, yes?) on either: R1(s0) or R3(s1)

So connect
R1(s0)DCE-clock <----> R2(sY)DTE-no-clock
If line protocol comes up, R1(s0) is now known good, too. If not, you found your problem with R1(s0).

If line protocol comes up, then connect
R3(s1)DTE-no-clock <----> R2(sX)DCE-clock
Again, check line protocol, if it comes up, you know R3(s1) is good. Otherwise you have found your problem with R3(s1).

The only IOS config you would do is:
"clock rate 56000" on the DCE-cabled serial port and
"no clock rate 56000" on the DTE-cabled serial port
You don't even have to save the config for the tests.


--jeff

http://linkedin.com/in/JeffLynch