Refer to the exhibit.
Clients in VLAN 10 complain that they cannot access network resources and the Internet. When
you try to ping the default gateway from one of the affected clients, you get ping timeouts. What is
the most likely cause of this issue?
A.
VLAN 10 is only enabled on trunk interfaces.
B.
VLAN 10 is not created in the switch database.
C.
STP is not running on the switch.
D.
IP routing is disabled on the switch.
E.
The switch CAM table is corrupted.
Explanation:
Troubleshooting the Autostate Feature on IOS Based Switches
Perform these troubleshooting steps if the VLAN interface is down.
This is the symptom of a VLAN interface being in up/down status.
Corgon-6000#sh int vlan 151
Vlan151 is up, line protocol is down
!— Line protocol on interface VLAN 151 is down.
!— You need to investigate why this line protocol is not up
!— (at least one L2 port exists, and there should be a
!— link up on this VLAN).
Check to make sure that VLAN 151 exists in the VLAN database and is active. The command
below shows that the VLAN exists and is active on the switch.
Corgon-6000#sh vlan 151 | i 151
151 VLAN151 active Gi4/10
151 enet 100151 1500 – – – – – 0 0
Corgon-6000#
!— VLAN 151 exists in VLAN database and is active.
!— L2 port Gig4/10 is assigned to VLAN 151.
Check the status of interface gig 4/10 assigned to VLAN 151.
Corgon-6000#sh int gig 4/10GigabitEthernet4/10 is up, line protocol is down (notconnect)
Corgon-6000#sh run int gig 4/10
Building configuration…
Current configuration : 182 bytes
!
interface GigabitEthernet4/10
no ip address
logging event link-status
logging event bundle-status
switchport
switchport access vlan 151
switchport mode access
end
The reason for the line protocol of interface VLAN 151 being down is because GigabitEthernet4/10
link is not connected, as seen from the interface status. It is possible that no device is connected
to the interface or that the link has cabling or auto-negotiation issues preventing the link from
being up.
Connect the device to GigabitEthernet4/10 to bring the interface link up.
Mar 11 12:10:52.340: %LINK-3-UPDOWN: Interface GigabitEthernet4/10, changed state to up
Mar 11 12:10:53.156: %LINEPROTO-5-UPDOWN: Line protocol on Interface
GigabitEthernet4/10, changed state to up
Corgon-6000#
Corgon-6000#
Corgon-6000#sh int vlan 151
Vlan151 is up, line protocol is down
Check that the VLAN interface shows that the line protocol is still down. You need to investigate
why this line protocol is not up. Make sure that at least one L2 port is in spanning-tree forwarding
state on this VLAN.
The Spanning-tree port status is LRN, which means learning state. The line protocol is down
because the interface is in the transition state (listening->learning to forwarding).
Corgon-6000# Mar 11 12:11:23.406: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Vlan151, changed state to up
Note: Time stamp difference between logs when the line protocol on GigabitEthernet4/10 went up,
and Interface Vlan151 is around 30 seconds, which represents 2xforwarding delay in STP
(listening-> learning->forwarding)
Corgon-6000#sh int vlan 151
Vlan151 is up, line protocol is up
The line protocol is up. You need to verify spanning-tree port status on the L2 port (should be
forwarding).
Corgon-6000#sh spanning-tree vlan 151
!— Verified spanning-tree port status on L2 port
!— is FWN = forwarding.http://www.cisco.com/en/US/products/hw/switches/ps708/products_tech_note09186a0080160b14.
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