VLAN Deletion/Re-creation Question

coolboarderguy · ‎10-29-2005

Hi All,

just brushing up on some basics, like creating vlans/trunks.vtp domains etc. Anyway, I did the below, but, upon re-creating vlan 2 after deleting it, the same status and ports were assigned to it. Should I have reloaded or something, after the delete, before re-creating.? I was of the understanding, that if you delete a vlan, the ports assigned to that vlan become assigned to no vlan.(meaning you gotta reassign them). I was planning to do just that, but, it happened all by itself. Cheers.

coolboarderguy...

coolboarderguy · ‎10-29-2005

Hi All,

output is below. Cheers.

coolboarderguy.

Cool#sh vlan

VLAN Name Status Ports

---- -------------------------------- --------- -------------------------------

1 default active Fa0/5, Fa0/7

2 highdruid act/lshut Fa0/1, Fa0/2, Fa0/3, Fa0/4

3 slick active Fa0/8, Fa0/9, Fa0/10, Fa0/11,

Fa0/12

1002 fddi-default active

1003 token-ring-default active

1004 fddinet-default active

1005 trnet-default active

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2

---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------

1 enet 100001 1500 - - - - - 0 0

2 enet 100002 1500 - - - - - 0 0

3 enet 100003 1500 - - - - - 0 0

1002 fddi 101002 1500 - - - - - 0 0

1003 tr 101003 1500 - - - - - 0 0

1004 fdnet 101004 1500 - - - ieee - 0 0

1005 trnet 101005 1500 - - - ibm - 0 0

Cool#vlan database

Cool(vlan)#no vlan 2

Deleting VLAN 2...

Cool(vlan)#exit

APPLY completed.

Exiting....

Cool#sh vlan

VLAN Name Status Ports

---- -------------------------------- --------- -------------------------------

1 default active Fa0/5, Fa0/7

3 slick active Fa0/8, Fa0/9, Fa0/10, Fa0/11,

Fa0/12

1002 fddi-default active

1003 token-ring-default active

1004 fddinet-default active

1005 trnet-default active

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2

---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------

1 enet 100001 1500 - - - - - 0 0

3 enet 100003 1500 - - - - - 0 0

1002 fddi 101002 1500 - - - - - 0 0

1003 tr 101003 1500 - - - - - 0 0

1004 fdnet 101004 1500 - - - ieee - 0 0

1005 trnet 101005 1500 - - - ibm - 0 0

Cool#vlan database

Cool(vlan)#vlan 2 name highdruid

VLAN 2 added:

Name: highdruid

Cool(vlan)#exit

APPLY completed.

Exiting....

Cool#sh vlan

VLAN Name Status Ports

---- -------------------------------- --------- -------------------------------

1 default active Fa0/5, Fa0/7

2 highdruid act/lshut Fa0/1, Fa0/2, Fa0/3, Fa0/4

3 slick active Fa0/8, Fa0/9, Fa0/10, Fa0/11,

Fa0/12

1002 fddi-default active

1003 token-ring-default active

1004 fddinet-default active

1005 trnet-default active

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2

---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------

1 enet 100001 1500 - - - - - 0 0

2 enet 100002 1500 - - - - - 0 0

3 enet 100003 1500 - - - - - 0 0

1002 fddi 101002 1500 - - - - - 0 0

1003 tr 101003 1500 - - - - - 0 0

1004 fdnet 101004 1500 - - - ieee - 0 0

1005 trnet 101005 1500 - - - ibm - 0 0

Cool#

glen.grant · ‎10-29-2005

I think it has something to with the fact that vlan 2 was not really active , if you look at the first display it shows vlan 2 as act/lshut which means the vlan was shutdown . Probably if you activated the vlan first and then deleted it . Also I don't think it is going to change the "switchport access vlan 2" settings on the switchports unless you manually change them even if you delete the vlan in the vlan database , the database doesn't have anything to do with the switchport settings , those are handled in the running config file.

ybajpai · ‎10-29-2005

Most newer Catalyst switches will add a vlan x automatically when you configure "switchport access vlan x" on a switchport interface. However, after that, if the vlan x was deleted, the config on that interface does NOT go away.

vlan information is stored in vlan.dat database and the interface config is stored in NVRAM. They are two separate information base. So what you see is expected on the Catalyst Switches.

Regards,

Yash