Vlan design

[DOUGLAS EVANS]

Working with a school district, core switch 4507R, Twenty-two 3550-PWR in various IDFs. Two Gigabit uplinks from each stack. They want to implement 10 different Vlans to minimize traffic. All the Vlans will need to routed as there will be only one server and one internet connection. Will the Vlans really buy them anything in this scenario ? I'm looking to present pros and cons on this design. Any ideas would be greatly appreciated. Thanks DJE

[roger.jones]

I would suggest that your hardware design is fine. the use of Vlans will be essential if you are using Ip phones ( I assume this is the case if 3550 inline power switches ) . Whilst this would all work as a single vlan ( or no vlan at all ) it is better to reduce your collision domains in the long run. Would suggest using 1 Vlan for Voice and a vlan for each area of the district. ( Or something similar ). also match each vlan to a subnet.

Pros are bandwidth, no propogation of faults across the enterprise ( Broadcasts etc )

cons are: a bit harder to manage IOS configuartion

[tsettle]

Vlans will buy you isolation and easier management of traffic. Vlans are separate broadcast domains so you will cut down on the traffic that each end station must see, but trunks will still have to pass it all. Vlans should be created so that the devices on each have some logical relationship, eg building#1, department A, Voice, Data, etc. This will allow for easier classification should you ever implement security or qos policies.

[SAM ANANDARAJAH]

Hi,

>I assume your design in core will have (2) 4507.and both 4507`s are connected via 1gig fibre ,are you eiherchannelling them ? ,if so at L2 or L3 ?

>Each access switches are connected via 1gig (total of 2gig/3550 ?)

> users I assume will have 9 vlans ,if so you can load balance them by assignning odd vlans to go through core switch(01),and even vlans via Switch(02)

! this way you are using the both switches and ,if you are etherchannel them from your gig port then you can load balance them ,so that both switches are working and sharing the loads all the time.!

> you can also make each vlans to perform the hsrp functions per vlans ,so the users will never have any failure,provided your server will have 2 nic cards and each one of them will be connected to s01 &s02.

> your single point of failure is your ISP connection.

* from your access switches 1gig to core,and both core switches are within 1-2 gig on them,and users are autoneg with speed and duplex.But your server will be 100meg full .and all your pc`ports are portfast enable ,so is server port.