Problem in creating Vlan on 3550

[kanupriya]

hi,

I have done stacking between two 3550 siwtches. On one switch already a Vlan is created and network is running. On another switch I have created another Vlan using "int Vlan 79" command and gave an ip address for that VLAN. Enabled routing for this ip address and configured many ports to access this VLAN and connected PCs also. When I give command "sh vlan id 79", the message is "No VLAN is found in database". I have checked the VTP domain mode it was in client mode, then I converted it into server mode, reboot the switch and create Int Vlan again. Result was same. Then just for trying I put command "VLAN 79" in config mode and now everything is running fine. It is showing it in database also.

My question is when we put "Int Vlan" command, generally it creates the VLAN, then why I need to out VLAN 79 command.

This is problem related to concept.

Looking forward for the suggestions.

Thanks

[amit-singh · Accepted solution]

Hi Kanupriya,

When you run the command " Int vlan 79 " and assign and IP to this, you are actually creating a SVI or the layer-3 virtual interface on the switch. This will not create Vlan 79 as a L-2 vlan in the Vlan database. When you run the command " Vlan 79 " that created the Vlan 79 in the Vlan database and you were able to see that Vlan interface. Remember to first define a L2- vlan in Vlan databse always, then configure the ports on this vlan and then define the L3 SVI.

You can also configure the L2 vlan by going into vlan datbase :

Switch# Vlan database

Switch(vlan)# Vlan 79 name V79

Switch(vlan)#exit

HTH,

-amit singh

[kanupriya]

hi,

Thanks to clear me on this point.

I appreciate your quick response and suggestion.

regards

kanupriya