01-27-2009 11:57 PM - edited 03-06-2019 03:42 AM
Hi, all
I wonder the meaning of "link type is auto"
that was shown in the output of command
"show int fa1/0"
GGJU4F_SSW_S4507#2#sh int fastEthernet 4/25
FastEthernet4/25 is up, line protocol is up (connected)
Hardware is Fast Ethernet Port, address is 001e.f7d9.ede8 (bia 001e.f7d9.ede8)
Description: ## Vlan 920 ##
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)
Carrier delay is 0 msec
Full-duplex, 100Mb/s, link type is auto, media type is 10/100BaseTX
input flow-control is unsupported output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters 00:20:48
Input queue: 0/2000/0/0 (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
1158 packets input, 92184 bytes, 0 no buffer
Received 0 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
1928 packets output, 152207 bytes, 0 underruns
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
Solved! Go to Solution.
01-29-2009 05:50 PM
Sorry i thought it was mdix at first glance and the previous comments on this thread.
4503-1(config-if)#do show run int g1/1
Building configuration...
Current configuration : 141 bytes
!
interface GigabitEthernet1/1
speed nonegotiate
end
4503-1(config-if)#do show int g1/1 | i Mb
Full-duplex, 1000Mb/s, link type is force-up, media type is 1000BaseSX
It has to do with 'speed nonegotiate'. I believe it has to do with if you copper to fiber conversion. Meaning you have this command available on fiber GBIC ports so you can attempt to negotiate with a remote copper end if necessary. Honestly, I am not 100% sure, but this command is only there on fiber ports and it does change the link type from auto.
01-28-2009 01:22 AM
Hello Sanghee,
the meaning is that the port has not been hard coded for a specific speed and duplex but it will try to negotiate with the NIC of the device connected to it both speed and duplex.
if instead you configure
int fas0/1
speed 100
duplex full
in sh int fas0/1 you should see
link type is 100 Full
Hope to help
Giuseppe
01-28-2009 04:53 PM
Thanks for your reply.
as you saying, I checked the configuration.
but it has been configured with speed 100 and duplex full already.
Um....
device is cat4507 with IOS_12.2(25)EWA10.bin
would you give me more explanation?
01-28-2009 05:42 PM
Hi hsh7603,
There are switches with more than one type of media for an interface. For exemple, a single interface can have two connector: a SPF (gbic) or rj-45. In such type of interface you may want to indicate using a command which one you will use. The configuration you choose is reflected in "link type".
int f0/24
media-type sfp
end
01-28-2009 06:36 PM
Thanks for your reply.
but the switch supports just RJ45 type.
I attatch the show module.
GGJU4F_SG_S4507#1#sh mod
Chassis Type : WS-C4507R
Power consumed by backplane : 40 Watts
Mod Ports Card Type Model Serial No.
---+-----+--------------------------------------+------------------+-----------
1 2 Supervisor IV 1000BaseX (GBIC) WS-X4515 JAE1126NBSK
2 2 Supervisor IV 1000BaseX (GBIC) WS-X4515 JAE1132SYPC
3 48 10/100BaseTX (RJ45) WS-X4148-RJ JAE1123KAJ7
5 6 1000BaseX (GBIC) WS-X4306-GB JAE1129R244
7 48 10/100BaseTX (RJ45) WS-X4148-RJ JAE1142070E
as you recommend
I try it, but media-type command are unseen.
Of course it is right because it doen't support any media-type except RJ45.
In this case,
Link type is shown as auto?
Um....I don't know....
01-28-2009 06:45 PM
mdix is probably what it is.
it is used to detect rx from tx incase you ran out of xover cables
'no mdix auto'
01-29-2009 07:00 AM
I have read that command "show int fa1/0" does not give a clue about speed or duplex being AUTO. So, I don't think that refers to speed or duplex settings.
Can that "link type auto" be related to auto-negotiate trunking?
01-29-2009 05:18 PM
So do I.
I can't find the "no mdix auto" in configuration.
It doen't seen in both global and interface configuration level.
I am finding the relationship with trunking.
Anyone knows about this issue??
01-29-2009 05:50 PM
Sorry i thought it was mdix at first glance and the previous comments on this thread.
4503-1(config-if)#do show run int g1/1
Building configuration...
Current configuration : 141 bytes
!
interface GigabitEthernet1/1
speed nonegotiate
end
4503-1(config-if)#do show int g1/1 | i Mb
Full-duplex, 1000Mb/s, link type is force-up, media type is 1000BaseSX
It has to do with 'speed nonegotiate'. I believe it has to do with if you copper to fiber conversion. Meaning you have this command available on fiber GBIC ports so you can attempt to negotiate with a remote copper end if necessary. Honestly, I am not 100% sure, but this command is only there on fiber ports and it does change the link type from auto.
01-29-2009 06:10 PM
Thanks for your reply.
It is very helpful to me.
I think it seems to be not necessary for fastehternet because it does not force interface into nonegotiate.
although I change the speed and duplex into 100/full, but "show interface" shows link type is auto.
so link type in fast-ethernet will seem to be auto always.(I am not 100% sure ^^)
Thanks a lot.
01-30-2009 05:06 AM
Maybe you have the "negotiation auto" configured in the port.
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