I am using a 3448 connecting to a cisco 3550.

First of all, VLAN 1 is always there and you will not be able to delete it.  However you can move all the ports from VLAN 1 to VLAN 2 if you want to use VLAN 2 for management instead.  As long as no interface belongs to VLAN 1 it will not be used.  Note that if you ever configure an interface so that it no longer belong to any other VLAN then it will revert back to VLAN 1.

Now I don't know what your configuration looks like right now so it maybe that you would need to specifically configure the ports instead of using a range depending on the configuration of the ports.

But assuming that your 3448 currently is in default state and you are not stacking your 3448 and all ports are in the default mode (i.e all ports are in access modes and belonging to VLAN 1) and you currently have an IP address assigned to VLAN 1 but want to change to use VLAN 2 for management instead.  Then you may try the following:

• Connect to the CLI using the serial interface (you need to do this because if you remove the IP address while in telnet then you will lose access).
• First remove the IP address from VLAN 1 (use "no ip address" command on "interface vlan 1" ).
• Next, create a VLAN 2.
• Then, use either of the following range commands to configure all the ports at once:
• • "interface range ethernet all"
  • "interface range ethernet e1-48"
• Assuming default mode then the ports are all in access mode right now so use this command to configure the VLAN to VLAN 2: "switchport access vlan 2".
• Finally configure the IP address on vlan 2 (use "ip address " command on "interface vlan 2" ).

So my configuration after I did the above looks something like this:

• vlan database
• vlan 2
• exit
• interface range ethernet all
• switchport access vlan 2
• exit
• interface vlan 2
• ip address 192.168.2.10 255.255.255.0
• exit

BTW, this example moves all the ports to VLAN 2 but the LAGs are still in VLAN 1.  If you do a "show vlan" you will see what I mean.  If you want to move the LAGs to VLAN 2 too then use the command "interface range port-channel all" to configure all the LAGs to VLAN 2 also.  After you do this you can use "show vlan" to confirm that no interface belongs to VLAN 1.

Cuong. 

Thanks so Much.

I will give it a shot and see what happens.

Post your config.  Also tell me exactly how the network is configured.  For example, Cisco is connected to trunk port G1 (how is Cisco configured) and where is the system you are trying to ping (which port on which switch).  Are you doing the ping from the workstation to the switch IP?  So I'm assuming the switch IP is 10.1.2.205 and the workstation IP is 10.1.2.201?  BTW, did you wait for at least 30 seconds before you do the ping?  Remember that if spanning tree is on, then spanning tree actually doesn't converge until about 30 seconds after the "link" is established (use port-fast or fast-link for STP port or use RSTP if you want faster convergence).

If after waiting 30 seconds for the STP to converge and you still can't ping then likely its something to do with your trunk.  You must configure the trunk native VLAN to 2 & probably add VLAN 2 to the trunk.  Is the traffic from VLAN 2 coming from your Cisco switch coming into the trunk as tagged or untagged?

Cuong.