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Interface Resets and lost carrier on 1750 router

slayerhawk
Level 1
Level 1

Hi all. I have users that are experiencing loss of service very intermittently without our HQ losing ping to the router. A sh tech produces the following on E0.

FastEthernet0 is up, line protocol is up

Hardware is PQUICC_FEC, address is 0001.422c.75e8 (bia 0001.422c.75e8)

Internet address is 192.168.18.1/24

MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

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

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Auto-duplex, 10Mb/s, 100BaseTX/FX

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:01, output 00:00:00, output hang never

Last clearing of "show interface" counters never

Queueing strategy: fifo

Output queue 0/40, 0 drops; input queue 0/75, 4 drops

5 minute input rate 3000 bits/sec, 4 packets/sec

5 minute output rate 9000 bits/sec, 4 packets/sec

3994218 packets input, 754940862 bytes

Received 76878 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog

0 input packets with dribble condition detected

5690378 packets output, 166480342 bytes, 0 underruns(11118/19841/0)

19647 output errors, 30959 collisions, 2 interface resets

0 babbles, 0 late collision, 0 deferred

6 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

Should I be concerned about the interface resets and lost carrier? In my mind, it points to a bad cable.

8 Replies 8

paolo bevilacqua
Hall of Fame
Hall of Fame

Hi, you have a lot of collisions, either set the 1750 to half-duplex, or both devices to full.

Hope this helps, please rate post if it does!

This is the interface on my switch. It doesn't show any resets, etc, so wouldn't it point to a cable issue or a fa0 issue on the router?

Ethernet 0/10 is Enabled

Hardware is Built-in 10Base-T

Address is 0003.6BFB.774A

MTU 1500 bytes, BW 10000 Kbits

802.1d STP State: Forwarding Forward Transitions: 1

Port monitoring: Disabled

Unknown unicast flooding: Enabled

Unregistered multicast flooding: Enabled

Description:

Duplex setting: Half duplex

Back pressure: Disabled

--More--

Receive Statistics Transmit Statistics

------------------------------------- -------------------------------------

Total good frames 36944 Total frames 33327

Total octets 21719159 Total octets 5330105

Broadcast/multicast frames 1378 Broadcast/multicast frames 2663

Broadcast/multicast octets 127838 Broadcast/multicast octets 192596

Good frames forwarded 36458 Deferrals 201

Frames filtered 486 Single collisions 59

Runt frames 0 Multiple collisions 66

No buffer discards 0 Excessive collisions 0

Queue full discards 0

Errors: Errors:

FCS errors 0 Late collisions 0

Alignment errors 0 Excessive deferrals 0

Giant frames 0 Jabber errors 0

Address violations 0 Other transmit errors 0

If you look at it carefully you will 201 deferrals, 66 multiple collisions, etc.

So please configure the 1750 for half duplex because now it not set like that.

I think cabling is fine so pls report after the change to either to full or half duplex on both sides.

This made no change today. The site mentioned that the problem started after receiving a new pc. How can I check for a jabbering nic?

It looks like a physical layer issue to me. If you suspect it may be the new NIC then check the switchport to which the new PC is connected to. You may see errors or excessive amount of traffic coming from that host.

HTH

Sundar

Here is a show interface of my catalyst 1900 for the port that has the pc that may be jabbering. Do you notice anything unusual?

Ethernet 0/15 is Enabled

Hardware is Built-in 10Base-T

Address is 0003.6BFB.774F

MTU 1500 bytes, BW 10000 Kbits

802.1d STP State: Forwarding Forward Transitions: 1

Port monitoring: Disabled

Unknown unicast flooding: Enabled

Unregistered multicast flooding: Enabled

Description:

Duplex setting: Half duplex

Back pressure: Disabled

--More--

Receive Statistics Transmit Statistics

------------------------------------- -------------------------------------

Total good frames 13169 Total frames 83400

Total octets 2736691 Total octets 7562356

Broadcast/multicast frames 575 Broadcast/multicast frames 70780

Broadcast/multicast octets 81590 Broadcast/multicast octets 5046683

Good frames forwarded 13169 Deferrals 186

Frames filtered 0 Single collisions 56

Runt frames 0 Multiple collisions 57

No buffer discards 0 Excessive collisions 0

Queue full discards 0

Errors: Errors:

FCS errors 0 Late collisions 0

Alignment errors 0 Excessive deferrals 0

Giant frames 0 Jabber errors 0

Address violations 0 Other transmit errors 0

As you can see the error counters are all 0s except the few collisions and deferred frames and thus there mayn't be a problem there. Try hardcoding the duplex to full on both the router and switch. If that doesn't help then you may have to start swapping out cable or moving the router connection to a different port on the switch.

HTH

Sundar

This is after replacing the cable from the router to switch yesterday. This is the show interface from fa0 on the 1700 router. I'm concerned about the "lost carrier". Should I be?

chr01rt01ec#sh int fa0

FastEthernet0 is up, line protocol is up

Hardware is PQUICC_FEC, address is 0001.422c.75e8 (bia 0001.422c.75e8)

Internet address is 192.168.18.1/24

MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

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

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Half-duplex, 10Mb/s, 100BaseTX/FX

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:11, output 00:00:01, output hang never

Last clearing of "show interface" counters 1d15h

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 1000 bits/sec, 1 packets/sec

222433 packets input, 46597044 bytes

Received 5074 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog

0 input packets with dribble condition detected

289627 packets output, 143297346 bytes, 0 underruns(676/1338/0)

1273 output errors, 2014 collisions, 0 interface resets

0 babbles, 0 late collision, 0 deferred

18 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

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