Troubleshooting guide

11-23
ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-01
Chapter 11 Troubleshooting Layer 3 Network Connections
Troubleshooting Half- or Full-Duplex Negotiation
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Switch#
Step 2 Check the Auto-duplex, Auto Speed, 100BaseTX fields. They should have the following default
configuration:
• Auto-duplex—Auto duplex negotiation
• Auto-Speed—Auto speed negotiation
• 100BASE-TX—100-Mbps BASE-TX
If they do not, check the peer interface and determine whether it is capable of this configuration.
Step 3 Use the show controllers fastEthernet card/subcard/port command to check the half-duplex and
full-duplex autonegotiation configuration.
Note The show controllers command for a specific interface has different information depending on the
IOS software version running on your Layer 3 enabled ATM switch router.
Step 4 Use the show controllers fastEthernet card/subcard/port command to check the configuration.
The following example uses the Cisco IOS Release 12.0(5)W5(13b) and later display:
Switch# show controllers fastEthernet 3/0/0
IF Name: FastEthernet3/0/0
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(Information Deleted)
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MII registers:
Control Register (0x0): 0x1000 (Auto negotiation enabled)
Status Register (0x1): 0x782D (Auto negotiation complete)
PHY Identification Register 1 (0x2): 0x7810
PHY Identification Register 2 (0x3): 0x43
Auto Neg. Advertisement Reg (0x4): 0x1E1 (Speed 100 ,Duplex Full )
Auto Neg. Partner Ability Reg (0x5): 0x81 (Speed 100 ,Duplex Half )
Auto Neg. Expansion Register (0x6): 0x0
Mirror Register (0x10): 0x630
Interrupt Enable Register (0x11): 0x0
Interrupt Status Register (0x12): 0x4000
Configuration Register (0x13): 0x0 (UTP, Tx Enabled)
Chip Status Register (0x14): 0x28C9 (Link Up,a-Half,a-100 )
Link Status Register [3-0]|[7-4]: 0x1|0x0
Counters :
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(Information Deleted)
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