How to know is the unmanageable router is it hard code with duplex
herewith example
ISP Router hard code with duplex
Router#sh run int fa0/1
Building configuration...
Current configuration : 166 bytes
!
interface FastEthernet0/1
ip address 10.154.88.1 255.255.255.0
no ip redirects
no ip proxy-arp
ip mtu 1400
ip tcp adjust-mss 1300
speed 100
full-duplex
end
Router#
Manageable Switch
Switch#sh int fa0/2
FastEthernet0/2 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is 9caf.cab5.eb02 (bia 9caf.cab5.eb02)
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, 100Mb/s, media type is 10/100BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:10, output 00:00:00, 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: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
405 packets input, 55364 bytes, 0 no buffer
Received 129 broadcasts (23 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 23 multicast, 0 pause input
0 input packets with dribble condition detected
2147 packets output, 183411 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
Switch#sh run int fa0/2
Building configuration...
Current configuration : 33 bytes
!
interface FastEthernet0/2
end
Switch#
Logging from manageable switch
*Mar 1 01:34:08.938: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on FastEthernet0/2 (not full duplex)
From above I know that the ISP/unmanageable router is hard code with duplex.
This also apply to laptop or server which hard code with duplex.
herewith my laptop hard code with duplex full duplex
Switch#sh int fa0/5
FastEthernet0/5 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is 9caf.cab5.eb05 (bia 9caf.cab5.eb05)
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, 100Mb/s, media type is 10/100BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 00:00:01, 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: fifo
Output queue: 0/40 (size/max)
5 minute input rate 1000 bits/sec, 1 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
1449 packets input, 143021 bytes, 0 no buffer
Received 1274 broadcasts (194 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 194 multicast, 0 pause input
0 input packets with dribble condition detected
1292 packets output, 97129 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
Switch#
