2.1 Configure and verify VLANs (normal range) spanning multiple switches.
Objective 2.1 sits in Network Access, which carries 20% of the CCNA exam. The questions below are original, written from the official objective title above, and each explanation cites the Cisco page it rests on.
Objective title verbatim from the official objectives. Cisco exam page ↗
A worked example
Shown solved, with the whole explanation open: this is what every question here carries.
A user on Gi1/0/8 lost connectivity after a maintenance window. The switch reports the following.
SW1# show interfaces gigabitethernet1/0/8 switchport
Name: Gi1/0/8
Switchport: Enabled
Administrative Mode: static access
Operational Mode: static access
Access Mode VLAN: 30 (Inactive)
Trunking Native Mode VLAN: 1 (default)
SW1# show vlan brief
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Gi1/0/1, Gi1/0/2
10 ENG active Gi1/0/3, Gi1/0/4
20 VOICE active Gi1/0/5What explains the port state?
The concept
An access port's VLAN membership is a static assignment stored on the interface, not a pointer that follows the VLAN database. If the database no longer holds that ID, the membership survives in the running configuration while the port stops passing traffic.
Why this answer
The brief listing shows 1, 10 and 20 only, so the ID the interface names is gone from the database. That is exactly the state the switch flags with Inactive next to the access VLAN, and the port stays that way until it is given an ID that exists.
- AIDs 1002 through 1005 are reserved for Token Ring and FDDI. That would be right had the configured ID fallen in that band, but 30 is normal range.
- BAn administratively shut interface reads Switchport: Enabled but shows a down line protocol in show interfaces status, and the access VLAN would not be qualified this way.
- CPruning limits which VLANs a trunk floods. It has no bearing on the membership an access port carries, which is what the qualifier here describes.
- Correct. The database no longer holds that ID, so the retained membership is unusable.
Now you: objective 2.1 questions
No account needed. The explanation opens when you answer.
Sample question 1 of 2
An engineer configures an access port on a switch whose database holds only VLANs 1, 10 and 20.
SW2(config)# interface gigabitethernet1/0/12
SW2(config-if)# switchport mode access
SW2(config-if)# switchport access vlan 45
SW2(config-if)# end
SW2#What happens to VLAN 45?
Sample question 2 of 2
A switch has used every spanning-tree instance it supports. A new VLAN is added in the VTP domain and its uplinks look like this.
SW3# show interfaces gigabitethernet1/0/24 trunk
Port Mode Encapsulation Status Native vlan
Gi1/0/24 on 802.1q trunking 1
Port Vlans allowed on trunk
Gi1/0/24 1-4094Which action limits the loop exposure?
That’s 2 of the full CCNA bank.
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Continue practicingRead the sources
These are the official pages the questions above cite. Reading them is studying the objective from the primary source, which is what the explanations point you toward anyway.