Serial interface issue. Mineseen = 0

Hey guys. I have a problem in my lab that I cant seem to figure out... its been over 6 hours now and I am ready to start throwing things out the window... Pls help me out.

I have two 2501 routers setup with a serial connection. S1 on one and S0 on the other...

I know for a fact that the S0 interface on one of the routers is ok bc I tested it with another port and it worked fine. However the S1 on my other router does not seem to work at all...

SO.. 2501C with S0 serial that I know works and 2501B with S1 that seems to not work.
Its not a cabling issue bc I have switched it out with 3 others that I know work on other identical connections. The cable is a DCE/DTE back to back...

Here is the sh con from both so we can eliminate the clockrate/DCE/DTE answers:

This is the 2501B S1 which I can not get to work with any router...

2501B#show controller s 1
HD unit 1, idb = 0x964B8, driver structure at 0x9A0E0
buffer size 1524  HD unit 1, V.35 DCE cable, clockrate 64000
cpb = 0x62, eda = 0x3000, cda = 0x3014
RX ring with 16 entries at 0x623000
00 bd_ptr=0x3000 pak=0x09CE28 ds=0x62D468 status=80 pak_size=22
01 bd_ptr=0x3014 pak=0x09BFC8 ds=0x629EA8 status=80 pak_size=0
02 bd_ptr=0x3028 pak=0x09CA90 ds=0x62C6F8 status=80 pak_size=0
03 bd_ptr=0x303C pak=0x09C8C4 ds=0x62C040 status=80 pak_size=0
04 bd_ptr=0x3050 pak=0x09C6F8 ds=0x62B988 status=80 pak_size=0
05 bd_ptr=0x3064 pak=0x09C52C ds=0x62B2D0 status=80 pak_size=0
06 bd_ptr=0x3078 pak=0x09C360 ds=0x62AC18 status=80 pak_size=0
07 bd_ptr=0x308C pak=0x09C194 ds=0x62A560 status=80 pak_size=0
08 bd_ptr=0x30A0 pak=0x09BDFC ds=0x6297F0 status=80 pak_size=0
09 bd_ptr=0x30B4 pak=0x09BC30 ds=0x629138 status=80 pak_size=0
10 bd_ptr=0x30C8 pak=0x09BA64 ds=0x628A80 status=80 pak_size=0
11 bd_ptr=0x30DC pak=0x09B898 ds=0x6283C8 status=80 pak_size=0
12 bd_ptr=0x30F0 pak=0x09B6CC ds=0x627D10 status=80 pak_size=0
13 bd_ptr=0x3104 pak=0x09B500 ds=0x627658 status=80 pak_size=0
14 bd_ptr=0x3118 pak=0x09B334 ds=0x626FA0 status=80 pak_size=0
15 bd_ptr=0x312C pak=0x09B168 ds=0x6268E8 status=80 pak_size=0
16 bd_ptr=0x3140 pak=0x09AF9C ds=0x626230 status=80 pak_size=0
cpb = 0x62, eda = 0x3814, cda = 0x3814
TX ring with 2 entries at 0x623800
00 bd_ptr=0x3800 pak=0x000000 ds=0x646148 status=80 pak_size=289
01 bd_ptr=0x3814 pak=0x000000 ds=0x646148 status=80 pak_size=17
02 bd_ptr=0x3828 pak=0x000000 ds=0x631964 status=80 pak_size=22
0 missed datagrams, 0 overruns
0 bad datagram encapsulations, 0 memory errors
0 transmitter underruns
0 residual bit errors

Here is the 2501C S0 that I had tried with other routers and it worked just fine...

2501C#show controller s 0
HD unit 0, idb = 0x8ED7C, driver structure at 0x92A18
buffer size 1524  HD unit 0, V.35 DTE cable
cpb = 0x81, eda = 0x4940, cda = 0x4800
RX ring with 16 entries at 0x814800
00 bd_ptr=0x4800 pak=0x094E64 ds=0x81D188 status=80 pak_size=0
01 bd_ptr=0x4814 pak=0x094C98 ds=0x81CAD0 status=80 pak_size=0
02 bd_ptr=0x4828 pak=0x094ACC ds=0x81C418 status=80 pak_size=0
03 bd_ptr=0x483C pak=0x094900 ds=0x81BD60 status=80 pak_size=0
04 bd_ptr=0x4850 pak=0x094734 ds=0x81B6A8 status=80 pak_size=0
05 bd_ptr=0x4864 pak=0x094568 ds=0x81AFF0 status=80 pak_size=0
06 bd_ptr=0x4878 pak=0x09439C ds=0x81A938 status=80 pak_size=0
07 bd_ptr=0x488C pak=0x094004 ds=0x819BC8 status=80 pak_size=0
08 bd_ptr=0x48A0 pak=0x093E38 ds=0x819510 status=80 pak_size=0
09 bd_ptr=0x48B4 pak=0x093C6C ds=0x818E58 status=80 pak_size=0
10 bd_ptr=0x48C8 pak=0x093AA0 ds=0x8187A0 status=80 pak_size=0
11 bd_ptr=0x48DC pak=0x0938D4 ds=0x8180E8 status=80 pak_size=0
12 bd_ptr=0x48F0 pak=0x095760 ds=0x81F320 status=80 pak_size=0
13 bd_ptr=0x4904 pak=0x095594 ds=0x81EC68 status=80 pak_size=0
14 bd_ptr=0x4918 pak=0x0953C8 ds=0x81E5B0 status=80 pak_size=0
15 bd_ptr=0x492C pak=0x0951FC ds=0x81DEF8 status=80 pak_size=0
16 bd_ptr=0x4940 pak=0x095030 ds=0x81D840 status=80 pak_size=0
cpb = 0x81, eda = 0x5000, cda = 0x5000
TX ring with 2 entries at 0x815000
00 bd_ptr=0x5000 pak=0x000000 ds=0x831964 status=80 pak_size=22
01 bd_ptr=0x5014 pak=0x000000 ds=0x831964 status=80 pak_size=22
02 bd_ptr=0x5028 pak=0x000000 ds=0x845A90 status=80 pak_size=286
0 missed datagrams, 0 overruns
0 bad datagram encapsulations, 0 memory errors
0 transmitter underruns
1 residual bit errors

Here is the show run from both.

2501C#show run
Building configuration...

Current configuration:
!
version 11.2
!
hostname 2501C
!
!
ip subnet-zero
no ip domain-lookup
!
interface Ethernet0
 ip address 172.16.50.1 255.255.255.0
!
interface Serial0
 ip address 172.16.40.2 255.255.255.0
!
interface Serial1
 no ip address
 shutdown
!
ip classless
banner motd ^CThis is the 2501C Router!^C
!
line con 0
 logging synchronous
line aux 0
line vty 0 4
 logging synchronous
 no login
!
end

2501B#show run
Building configuration...

Current configuration:
!
version 11.2
!
hostname 2501B
!
!
ip subnet-zero
!
interface Ethernet0
 ip address 172.16.30.1 255.255.255.0
!
interface Serial0
 ip address 172.16.20.2 255.255.255.0
 clockrate 64000
!
interface Serial1
 ip address 172.16.40.1 255.255.255.0
 clockrate 64000
!
ip classless
banner motd ^CThis is the 2501B Router!^C
!
line con 0
 logging synchronous
line aux 0
line vty 0 4
 logging synchronous
 no login
!
end

I dug around on this site and MANY others and I found the "debug serial interface" and this is what it says on the S1 port of 2501B. The same one I believe has a issue...

2501B#debug serial interface
Serial network interface debugging is on
2501B#
HD(0): New serial state = 0x005F

HD(0): DTR is up.
HD(1): got an interrupt state = 0x8055
HD(1): New serial state = 0x0055

HD(1): DTR is down.
HD(0): New serial state = 0x005F

HD(0): DTR is up.
HD(1): got an interrupt state = 0x805F
HD(1): New serial state = 0x005F

HD(1): DTR is up.
2501B#
Serial0: HDLC myseq 48, mineseen 48*, yourseen 49, line up
HD(1): Reset from 0x302680E
Serial1: HDLC myseq 48, mineseen 0*, yourseen 49, line down
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to down
2501B#
Serial0: HDLC myseq 49, mineseen 49*, yourseen 50, line up
Serial1: HDLC myseq 49, mineseen 0*, yourseen 50, line up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to up
2501B#
Serial0: HDLC myseq 50, mineseen 50*, yourseen 51, line up
HD(1): Reset from 0x302680E
Serial1: HDLC myseq 50, mineseen 0*, yourseen 51, line up
2501B#
HD(0): New serial state = 0x005F

HD(0): DTR is up.
HD(1): got an interrupt state = 0x8055
HD(1): New serial state = 0x0055

HD(1): DTR is down.
HD(0): New serial state = 0x005F

HD(0): DTR is up.
HD(1): got an interrupt state = 0x805F
HD(1): New serial state = 0x005F

HD(1): DTR is up.
2501B#

Now I am no genius, but I believe that mineseen = 0 is a problem. I cant seem locate what it means but my guess is that in the sequence on the port I am not seeing jack... ?

Any help guys pls pls pls...

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Comments

LOkrasa

I figured I would through in the ip int as well...

2501B#show ip int brief
Interface              IP-Address      OK? Method Status                Protocol
Ethernet0              172.16.30.1     YES NVRAM  up                    down
Serial0                172.16.20.2     YES NVRAM  up                    up
Serial1                172.16.40.1     YES NVRAM  up                    down

2501C#show ip int brief
Interface              IP-Address      OK? Method Status                Protocol
Ethernet0              172.16.50.1     YES manual up                    down
Serial0                172.16.40.2     YES manual up                    down
Serial1                unassigned      YES manual administratively down down

and on the 2501B the S1 is flapping... up/down/up/down/up/down/up/down....

tech-airman

LOkrasa,

Questions:

On router 2501B, did you try "ping 172.16.40.2?"
On router 2501C, did you try "ping 172.16.40.1?"
How come there's no routing protocols configured, not even static routes in the "running-config?"

LOkrasa

Yes. I knew i was missing something... here you go

2501B#ping 172.16.40.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.40.2, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

2501C#ping 172.16.40.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.40.1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

LOkrasa

I also can not ping the interfaces from the routers themselves... meaning from 2501B to the S1 interface on the router and on 2501C to the S0... both also come back just the same as above.

tech-airman

LOkrasa wrote:

I also can not ping the interfaces from the routers themselves... meaning from 2501B to the S1 interface on the router and on 2501C to the S0... both also come back just the same as above.

LOkrasa,

Looks like you replied twice while I was editing my post. Therefore, I'd like to ask why there is no routing protocol configured?

LOkrasa

I was going to setup static routes but I just wanted to make sure my connections were all good before I got into it... I am basically setting it all up for the first time.

tech-airman

LOkrasa wrote:

I was going to setup static routes but I just wanted to make sure my connections were all good before I got into it... I am basically setting it all up for the first time.

LOkrasa,

How about just configuring RIP for the time being?

LOkrasa

Configure RIP on just both the routers? I can do that...

LOkrasa

Ok I set it up... Is their something you would like me to run? I dont think setting up RIP is going to fix the connection issue... If I cant ping from one to the other across the connection, the RIP updates wont go across either.

tech-airman

LOkrasa wrote:

Ok I set it up... Is their something you would like me to run? I dont think setting up RIP is going to fix the connection issue... If I cant ping from one to the other across the connection, the RIP updates wont go across either.

LOkrasa,

Did you know that "ping packets" which are technically ICMP packets also need to be routed therefore need a routing protocol?

LOkrasa

tech-airman wrote:

LOkrasa wrote:

Ok I set it up... Is their something you would like me to run? I dont think setting up RIP is going to fix the connection issue... If I cant ping from one to the other across the connection, the RIP updates wont go across either.

LOkrasa,

Did you know that "ping packets" which are technically ICMP packets also need to be routed therefore need a routing protocol?

I think if you are pinging b/w directly connected devices you don't need a routing protocol. You would if their was another router involved...

dtlokee

LOkrasa wrote:

I think if you are pinging b/w directly connected devices you don't need a routing protocol. You would if their was another router involved...

You are correct, there is no need for a routing protocol or static routes in this case. You are also correct int the sequence numbers not being correct, they should look line this:

*Mar  7 06:35:05.211: Serial1/1: HDLC myseq 0, mineseen 0*, yourseen 1, line up 
R5(config-if)#
*Mar  7 06:35:11.627: %OSPF-5-ADJCHG: Process 1, Nbr 4.4.4.4 on Serial1/1 from LOADING to FULL, Loading Done
R5(config-if)#
*Mar  7 06:35:15.211: Serial1/1: HDLC myseq 1, mineseen 1*, yourseen 2, line up 
R5(config-if)#
*Mar  7 06:35:25.211: Serial1/1: HDLC myseq 2, mineseen 2*, yourseen 3, line up 
R5(config-if)#
*Mar  7 06:35:35.211: Serial1/1: HDLC myseq 3, mineseen 3*, yourseen 4, line up 
R5(config-if)#
*Mar  7 06:35:45.211: Serial1/1: HDLC myseq 4, mineseen 4*, yourseen 5, line up 
R5(config-if)#
*Mar  7 06:35:55.211: Serial1/1: HDLC myseq 5, mineseen 5*, yourseen 6, line up 
R5(config-if)#
*Mar  7 06:36:05.211: Serial1/1: HDLC myseq 6, mineseen 6*, yourseen 7, line up 
R5(config-if)#
*Mar  7 06:36:15.211: Serial1/1: HDLC myseq 7, mineseen 7*, yourseen 8, line up

I see some messages in there about DCD dropping out, what do you see in the output of "show interfaces serial 0"

R5#sh interfaces serial 1/1
Serial1/1 is up, line protocol is up 
  Hardware is QUICC Serial
  Internet address is 144.16.45.5/24
  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 00:00:03, output 00:00:02, output hang never
  Last clearing of "show interface" counters never
  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 1158 kilobits/sec
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     147 packets input, 12074 bytes, 0 no buffer
     Received 68 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     144 packets output, 11648 bytes, 0 underruns
     0 output errors, 0 collisions, 4 interface resets
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions
     DCD=up  DSR=up  DTR=up  RTS=up  CTS=up

Notice the last line, it needs to have all of them up, these are pins n the interface itself that tell the router the status of the other side and report the status of this side to the other side.

I have seen similar problems in the labs at my school, a couple of times it was because somone connected the serial cable upside down, one would think that would be impossible because it's a D shaped connector, but it can be done.

LOkrasa

I checked the cable and it is in correctly (not upside down). I know what you mean bc I once did put it in upside down... I dont know how it happened but it fit. hehe Here are the show interfaces:

S0 from 2501C

2501C#show interfaces serial 0
Serial0 is up, line protocol is down
  Hardware is HD64570
  Internet address is 172.16.40.2/24
  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 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 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     10 packets output, 734 bytes, 0 underruns
     0 output errors, 0 collisions, 11 interface resets
     0 output buffer failures, 0 output buffers swapped out
     12 carrier transitions
     DCD=up  DSR=up  DTR=up  RTS=up  CTS=up

S1 2501B

2501B#show interfaces s 1
Serial1 is up, line protocol is down
  Hardware is HD64570
  Internet address is 172.16.40.1/24
  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 00:00:00, output 00:00:00, 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  0/1 (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
     15 packets input, 589 bytes, 0 no buffer
     Received 15 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     24 packets output, 2310 bytes, 0 underruns
     0 output errors, 0 collisions, 8 interface resets
     0 output buffer failures, 0 output buffers swapped out
     9 carrier transitions
     DCD=up  DSR=up  DTR=up  RTS=up  CTS=up

Yeah it stays up like that for all of them the whole time on both interfaces... I never saw it go to a down state once yesterday either.

mwgood

Your config looks fine to me. There is no need for a routing protocol to ping a node on a connected network.

My guess is that you may have a bad serial port on one side or the other. I suggest trying the other serial ports.

dtlokee

Yeah mist likely a bad interface, or a bad connector on the interface. Your output shows 24 packet output on RouterC and no packets input on RouterB. I would try connecting RouterC to a different serial interface that you know works and eliminate the bad interface

LOkrasa

Thats what I was afraid of...

Yeah the 2501C interface works fine when I use it with other routers but the serial on 2501B doesn't seem to work no matter what I hook it up to... I guess its cheaper to just buy a whole new 2501 router then to go and replace the interface huh?

manic

somewhat irrelevant but it would be good practice to only use /30 subnets for the serial connections

LOkrasa

Yeah this is what the lab in the Sybex book wanted so I just went with their scheme of things.