Cisco: show run vlan # vs show run int vlan #

Question

What is the difference between the two commands?

  Show run vlan # = blank output
  show run int vlan # = vlan configuration

Likewise:

  show vlans
    No virutal LANs configured

  show vlan
    A bunch of output displaying interfaces and their respective vlans.

What is the difference between the two?

Solution

The "show run int" shows the portion of the configuration in NVRAM that defines the actual interface. The second command (sh vlan) actually shows the live state of the VLAN's (nb - sh vlan id xxx for a single VLAN ID, if platform supports it) as actively kept in switch's database. One command shows the actual configuration, the other a portion of the running state.

Comments

[ewwhite]

What information are you interested in obtaining?

[SpacemanSpiff]

The difference is, one shows L2 information, the other shows L3 RVI's associated with those same L2 logical configurations.