02-26-2016 02:21 PM - edited 03-08-2019 04:45 AM
Hi guys,
on one of my switch, I found this interface on a show run:
XXX#show interface description
Interface Status Protocol Description
Vl1 admin down down
Vl9 up up
Vl200 admin down down
Fa0/1 down down Disponibile
Fa0/2 up up Utilizzata
Fa0/3 down down Utilizzata
Fa0/4 down down Utilizzata
Fa0/5 up up Utilizzata
Fa0/6 down down Utilizzata
Fa0/7 up up Utilizzata
Fa0/8 down down Disponibile
Fa0/9 down down Utilizzata
Fa0/10 down down Disponibile
Fa0/10.15 down down
Fa0/11 down down Disponibile
Fa0/12 up up Disponibile
it seems a "subif" but it had never happened before, can anyone help?
regards
02-27-2016 01:08 PM
Hi,
Can you post the output of "show run" and "show ver"?
03-01-2016 11:48 AM
show run
interface FastEthernet0/10
description x
switchport access vlan x
switchport mode access
switchport voice vlan 153
no logging event link-status
no snmp trap link-status
storm-control broadcast level 10.00
storm-control action shutdown
no cdp enable
spanning-tree portfast
spanning-tree bpduguard enable
!
interface FastEthernet0/10.15
!
interface FastEthernet0/11
description x
switchport access vlan x
switchport mode access
switchport voice vlan 153
no logging event link-status
no snmp trap link-status
storm-control broadcast level 10.00
storm-control action shutdown
no cdp enable
spanning-tree portfast
spanning-tree bpduguard enable
!
show ver
show version
Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6K2L2Q4-M), Version 12.1(22)EA14, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by cisco Systems, Inc.
02-29-2016 03:32 AM
Hello,
It's just a subinterface. You can create a virtual interface from an physical one. The command is as simple as typing in global config : interface fa 0/nn.nn
03-01-2016 11:51 AM
ok, as I imagined it is a subif. What use i can make of a subif on a device like a 2950?
03-01-2016 12:22 PM
As far as I know you can't make any use of it.
In fact I am surprised it let you create it because a subinterface is associated with a L3 port and the 2950 is a L2 not a L3 switch.
Never seen that before.
Jon
03-01-2016 12:43 PM
Me too never seen that before, that's why I asked. Ok, summarize: it's a subif, and it's useless on a level 2 device....right? :D
03-01-2016 01:08 PM
As far as I can tell yes because you cannot assign an IP to that subinterface.
Jon
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