Help with VLAN design

olsonc0510 · ‎08-04-2006

We want to introduce VLAN's into an existing network. Currently, I have several blade enclosures with Cisco Switches attached. Each enclosure holds 8 blade servers. Right now each enclosure is on it's own subnet. One for web servers and one for terminal servers. We want to be able to mix web servers and terminal servers in the same enclosure, thus the VLAN's. From what I understand, we would need to introduce another subnet for the mgt VLAN.

How does this affect the existing network?

If I add a mgt. VLAN to the next new enclosure switch, do I have to change all the other blade enclosure switches so that they are on the same mgt. VLAN or will it only affect the new switch? I'm thinking it will affect every switch in the network along with the routers as well but if there is an easier way, I'd sure like to know it.

192.168.166.0 webservers

192.168.167.0 terminal servers

192.168.168.0 mgt VLAN ?

Roberto Salazar · ‎08-04-2006

If I add a mgt. VLAN to the next new enclosure switch, do I have to change all the other blade enclosure switches so that they are on the same mgt. VLAN or will it only affect the new switch? I'm thinking it will affect every switch in the network along with the routers as well but if there is an easier way, I'd sure like to know it.

>>> the point behind the vlan mgmt is that we want to separate user traffic completely so that when there is problem with the user vlan, the access to switch through telnet will not be hindered, that is the theory. From your description each switch serves a particular subnet and the switch mgmt interface is also in the same subnet and what are trying to accomplish now is to have the mgmt inteface of the switches to be in the different subnet or vlan. If my understanding is corect, then you you will need to create vlans on the switch (vlan for the websers, etc and for the mgmt interface) this will mean you will alos need to modify the existing switches configuration at least the mgmt interface. If all the switches currently have no vlans and left a default that means each switch's connection to the other switch is an access port. Once you move the mgmt. interface in it's own vlan, you will need to turnk the connection to the other switch.

http://www.cisco.com/univercd/cc/td/doc/product/lan/c3550/12225see/scg/swvlan.htm

http://www.cisco.com/en/US/tech/tk389/tk390/technologies_configuration_example09186a00800949fd.shtml

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