ā06-05-2013 12:01 AM - edited ā03-07-2019 01:43 PM
I have C3750X with C3KX-NM-10G, and have-T SFP in slot 3 ( means it is not in SFP+ slot ).
I need to set speed&duplex hard to 100/Full, but if I do the link goes down. I have the same settings on the other side, only IOS version is different.
I tried other speeds - 10 and 1000, but no one works with Full. When I change duplex to Auto it works fine.
The reason why I am doing this on C3KX-NM-10G is because I need to use NetFlow and cannot use the chassis' copper port. At the moment the ports are connected through a copper patch cord, but in full production there will be a radio link in between that requires 100M/Full to be set hard.
I am trying to search for any document that would describe this limitation, but cannot find any. Also port capabilities do not indicate duplex could not be set to full:
show interfaces g1/1/3 capabilities
GigabitEthernet1/1/3
Model: WS-C3750X-48P
Type: 10/100/1000BaseTX SFP
Speed: 10,100,1000,10000,auto
Duplex: half,full,auto
Trunk encap. type: 802.1Q,ISL
Trunk mode: on,off,desirable,nonegotiate
Channel: yes
Broadcast suppression: percentage(0-100)
Flowcontrol: rx-(off,on,desired),tx-(none)
Fast Start: yes
QoS scheduling: rx-(not configurable on per port basis),
tx-(4q3t) (3t: Two configurable values and one fixed.)
CoS rewrite: yes
ToS rewrite: yes
UDLD: yes
Inline power: no
SPAN: source/destination
PortSecure: yes
Dot1x: yes
Any help is appreciated.
Solved! Go to Solution.
ā06-10-2013 08:09 AM
Sounds to me like you don't have the correct cable and auto mdix is correcting for it . Auto mdix "only" works as auto/auto and it will take the ports down if not auto . You would need a crossover cable if you want to hardcode the ports.
ā06-05-2013 12:08 AM
I am very sure GLC-T is set to 1 Gbps, full duplex and no less.
Can you post the output to the command "sh interface Gig 1/1/3 status"?
ā06-05-2013 12:28 AM
If the port settings are
speed auto 10 100
on both sides ( duplex is auto by default )
I get the link up
sh int g1/1/3
GigabitEthernet1/1/3 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 4403.a7c7.6d33 (bia 4403.a7c7.6d33)
Description:
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 100Mb/s, link type is auto, media type is 10/100/1000BaseTX SFP
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, 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: fifo
Output queue: 0/40 (size/max)
5 minute input rate 58000 bits/sec, 63 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
187640 packets input, 21534917 bytes, 0 no buffer
Received 156115 broadcasts (135450 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 135450 multicast, 0 pause input
0 input packets with dribble condition detected
10717 packets output, 1576239 bytes, 0 underruns
0 output errors, 0 collisions, 3 interface resets
120 unknown protocol drops
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
If the port settings are
speed 100
duplex full
on both sides
I get the link down. The same applies if I change the speed to any speed 10, 100 or 1000.
sh int g1/1/3
GigabitEthernet1/1/3 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet, address is 4403.a7c7.6d33 (bia 4403.a7c7.6d33)
Description:
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 100Mb/s, link type is auto, media type is 10/100/1000BaseTX SFP
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:27, output 00:00:23, 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 51000 bits/sec, 56 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
198105 packets input, 22717767 bytes, 0 no buffer
Received 164553 broadcasts (142758 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 142758 multicast, 0 pause input
0 input packets with dribble condition detected
11417 packets output, 1641822 bytes, 0 underruns
0 output errors, 0 collisions, 3 interface resets
127 unknown protocol drops
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
ā06-05-2013 12:34 AM
Just adding sh int status for the two cases
#sh int g1/1/3 status
Port Name Status Vlan Duplex Speed Type
Gi1/1/3 connected trunk a-full a-100 10/100/1000BaseTX SFP
l
#sh int g1/1/3 status
Port Name Status Vlan Duplex Speed Type
Gi1/1/3 notconnect trunk full 100 10/100/1000BaseTX SFP
ā06-10-2013 07:09 AM
Good morning Vladimir.
I see a lot of duplex mismatch in the logs:
Jun 5 08:02:04.355: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on GigabitEthernet3/1/3 (not full duplex), with lonn2025 GigabitEthernet1/1/3 (full duplex). (lonn2001-3)
Upon initialization, each device transmits a 16 bit message called a fast link pulse burst, because of fastethernet to its link partner, which is used to negotiate, if you hardcode the interface in one end, the fast link pulse burst will sent 16 bit message with all its bits turned off, and the neighbor won't be able to understand that message.
Action plan:
Hard code both interfaces.
Loop the wire between the two copper interfaces in the C3KX module, interface 2 and 4 if I'm not mistaken. ( is it coming up?)
What is it connected in the other side?
Regards
Wilson B
ā06-10-2013 08:09 AM
Sounds to me like you don't have the correct cable and auto mdix is correcting for it . Auto mdix "only" works as auto/auto and it will take the ports down if not auto . You would need a crossover cable if you want to hardcode the ports.
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