Re: DUPLEX MIsmatch Issue

raza · ‎09-22-2004

I have this seniorio

2600 FE0/0----Aperto-------Wireless Link---E0/1 3600

All interfaces are Fullduplex but still getting

on 2600

%CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on FastEthernet0/0 (not half duplex), with 3640 Ethernet0/1 (half duplex).

On 3600

%CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on Ethernet0/1 (not full duplex), with 2600 FastEthernet0/0 (full duplex).

Kevin Dorrell · ‎09-22-2004

It would seem that your 3600 is configured half-duplex. Alternatively, it might be configured auto and the wireless link kit is not negotiating. With the wireless link, you will probably have to force the duplex on both sides. Of course, you will have to set it according to the capabilities of the wireless link.

Kevin Dorrell

Luxembourg

raza · ‎09-22-2004

Ok thanks but configrution at both ends is FDX

Regards

Kevin Dorrell · ‎09-22-2004

That may be configured, but the CDP is telling you a different story. So either the CDP is lying, or the interfaces are not doing what is configured.

Let's look at your messages:

On 2600: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on FastEthernet0/0 (not half duplex), with 3640 Ethernet0/1 (half duplex). This seems to be saying that the 3640 is running half-duplex on E0/1.

On 3600 : %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on Ethernet0/1 (not full duplex), with 2600 FastEthernet0/0 (full duplex). This also seems to be saying that the 3640 is running half-duplex.

Please could you post the "show int E0/1" and the "show run int E0/1" from the 3640.

What module are you using for the Ethernet? Is it an NM-4E or is it an NM-2E2W? The NM-2E2W supports full-duplex only from IOS 12.0(4)T onwards. Could this be the problem? What version are you running? See:

http://www.cisco.com/warp/public/107/nm-e2w.shtml

Kevin Dorrell

Luxembourg

raza · ‎09-22-2004

Thanks for reply This is NM2E2W but IOS is 12.2(1),

Pls see

Cisco Internetwork Operating System Software

IOS (tm) 3600 Software (C3640-IS-M), Version 12.2(1), RELEASE SOFTWARE (fc2)

Compiled Fri 27-Apr-01 03:19 by cmong

Image text-base: 0x60008950, data-base: 0x61156000

ROM: System Bootstrap, Version 11.1(19)AA, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)

3640 uptime is 3 days, 2 hours, 55 minutes

System returned to ROM by power-on

System restarted at 00:44:00 PST Mon Mar 8 1993

System image file is "flash:c3640-is-mz.122-1.bin"

cisco 3640 (R4700) processor (revision 0x00) with 61440K/4096K bytes of memory.

Processor board ID 11877871

R4700 CPU at 100Mhz, Implementation 33, Rev 1.0

Bridging software.

X.25 software, Version 3.0.0.

2 Ethernet/IEEE 802.3 interface(s)

4 Serial network interface(s)

8 Low-speed serial(sync/async) network interface(s)

DRAM configuration is 64 bits wide with parity disabled.

125K bytes of non-volatile configuration memory.

16384K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102

interface Ethernet0/1

description ***Khi_***Aperto Wireless Bridge***

ip address 145.17.63.242 255.255.255.252

ip ospf cost 400

load-interval 30

full-duplex

!

Kevin Dorrell · ‎09-23-2004

OK, that eliminates the IOS as the culprit. And I do see that full-duplex is configured. Please could you do a "show int E0/1"? And also a "show cdp neighbor E0/1 detail"?

Thanks.

Kevin Dorrell

Luxembourg

raza · ‎09-23-2004

sh int e0/1

Ethernet0/1 is up, line protocol is up

Hardware is AmdP2, address is 0050.7343.dec2 (bia 0050.7343.dec2)

Description: ***Khi_DRP-AMZ***Aperto Wireless Bridge***

Internet address is 145.17.63.242/30

MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,

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

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

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

Last input 00:00:00, 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, 0 drops

30 second input rate 17000 bits/sec, 6 packets/sec

30 second output rate 8000 bits/sec, 7 packets/sec

1084017 packets input, 681491984 bytes, 0 no buffer

Received 49813 broadcasts, 0 runts, 0 giants, 0 throttles

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

0 input packets with dribble condition detected

1112731 packets output, 163192486 bytes, 0 underruns(0/0/0)

8 output errors, 0 collisions, 5 interface resets

0 babbles, 0 late collision, 0 deferred

8 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

Kevin Dorrell · ‎09-23-2004

It's strange it does not specify the duplex. Normally I would expect to see that between the "Keepalive" line and the "ARP" line. However, I see that there have been no collisions at all, so I can believe it really is full duplex.

It is beginning to look as if the CDP is lying. What do you get for "show cdp neighbor E0/1" ?

Kevin Dorrell

Luxembourg

raza · ‎09-23-2004

Pls see

2600#sh cdp neighbors detail

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

Device ID: 3640

Entry address(es):

IP address: 145.17.63.242

Platform: cisco 3640, Capabilities: Router

Interface: FastEthernet0/0, Port ID (outgoing port): Ethernet0/1

Holdtime : 133 sec

Version :

Cisco Internetwork Operating System Software

IOS (tm) 3600 Software (C3640-IS-M), Version 12.2(1), RELEASE SOFTWARE (fc2)

Compiled Fri 27-Apr-01 03:19 by cmong

advertisement version: 2

Duplex: half

===========================================================================

3640#sh cdp neighbors detail

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

Device ID: 2600

Entry address(es):

IP address: 145.17.63.241

Platform: cisco 2651XM, Capabilities: Router Switch

Interface: Ethernet0/1, Port ID (outgoing port): FastEthernet0/0

Holdtime : 165 sec

Version :

Cisco Internetwork Operating System Software

IOS (tm) C2600 Software (C2600-IS-M), Version 12.2(11)T3, RELEASE SOFTWARE

(fc2)

TAC Support: http://www.cisco.com/tac

Compiled Sun 22-Dec-02 07:28 by ccai

advertisement version: 2

VTP Management Domain: ''

Duplex: full

Note in 3600 default speed is auto and I saw somewhere that we cannot change default Half duplex unless speed is non auto More I cannot change speed on this ethernet'

Kevin Dorrell · ‎09-23-2004

Speed and duplex negotiation works on FastEthernet interfaces. Normal 'E' interfaces are fixed at 10 Mbps, so there is no negotiation, i.e. no "auto". On an 'E' interface, the default (in fact the only option) is fixed 10 Mbps. Only the duplex can be changed, if the IOS permits.

The CDP seems to be convinced that it is half-duplex. But the collisions=0 tells me it is full- duplex. This looks to me like a bug in the CDP, but I couldn't find any reference to it in the bug database. I think you should raise a TAC case through your support channel.

Sorry I cannot solve it for you.

Kevin Dorrell

Luxembourg.

wmeech · ‎09-23-2004

On the 3600 try this command and check the duplex setting on line 9 of the output:

show controllers ethernet 0/1

You might find that your Full Duplex configuration command is being ignored.

Regards

raza · ‎09-23-2004

Thanks for reply

sh contr e0/1

Interface Ethernet0/1

Hardware is AMD Presidio2

ADDR: 61E6DE98, FASTSEND: 6002C048, MCI_INDEX: 0

DIST ROUTE ENABLED: 0

Route Cache Flag: 1

LADRF=0x0080 0x0000 0x0002 0x0000

CSR0 =0x00000072, CSR3 =0x00001044, CSR4 =0x0000491D, CSR15 =0x00000000

CSR80 =0x0000D900, CSR114=0x00000000, CRDA =0x03D3F2E0, CXDA =0x03D3F840

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

BCR9 =0x00000001 (full-duplex)

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

HW filtering information:

Promiscuous Mode Disabled, PHY Addr Enabled, Broadcast Addr Enabled

wmeech · ‎09-26-2004

Oh well. That's all I can think of.

I would say this is confirmation that the port is indeed operating in FDX mode.