VLAN's and unmanaged switches

[stompin]

Ok. V. Tight Company here who will only pay for one managed L3 12 or 24 port switch. I will be using this managed switch to setup 4 VLAN's for depts. The other ports will use L2 for servers. My question is this.. would it be OK to config each of the 4 VLAN's and then plug unmanaged switches into them resulting in all machines plugged into the unmanaged switches being a member of the VLAN?. Does this make sense?. I am sure I can do this but I need to know for sure before I go buy the L3 switch.

So it will go like this - VLAN 2 on managed switchport has an unmanaged switch plugged into the VLAN 2 port. All machines then plugged into the unamaged switch will be members of VLAN 2 etc.. Unmanaged switches will be stackable.

Any thought or alternative suggestions?

stompin

 

[leedsit]

Yup, that will work.

I.E you have a 12 port multilayer switch, each port is configured in a VLAN or as a Router Port (noswitchport ).

Each Port will then have a l2 switch connected via a cross over which is flat, that flat switch can then have as many devices on as you want ( Bar cisco per port mac limit ( normally 1024 )).

However dont forget if your Multilayer switch port is 100Meg, that bandwidth will be deviced by the amount of devices on that port. I.E 20 device, get an average of 5meg each.



LEEroy
MCNE6,CCNA2,CWNA, Project+

 

[stompin]

Cheer's for that.. just to clear things up here. If I plug my servers into the L3 switch they should all be on VLAN 1 (default VLAN) right?, so I guess access to these devices will need to be routed aswell (from dept VLAN's), so there's no L2 switching going on to hit the servers - or is there?

BW issue - I'm gonna be using a gig L3 switch with a mix of Gig & 100Meg unmanaged switches beneath

 

[leedsit]

Urm, Anything in Vlan 1 either directly connected to your Multilayer switch (MLS) or on a flat switch connected to your MLS port will talk to each other at layer 2, that is it is switched on Layer 2 Infomation (MAC), if you have another port on your MLS in VLAN 2, anything directly connected to that PORT on your MLS or on a Flat switch connected that PORT will have to Route to the servers/devices on VLAN 1, that is, it is routed/switched based on layer 3 information, IP Address.


LEEroy
MCNE6,CCNA2,CWNA, Project+

 

[stompin]

Ok were on a roll now - what about setting up the IP addresses for the VLAN's. How do I tell each VLAN which subnet (Ip address) they are on. And if I am using a DHCP server on VLAN 1 (on the L3 switch) how would I enable all machines on the other VLAN's to get an IP address from the DHCP server?

As you can see I am pretty new to VLAN's!

 

[leedsit]

Hi,

you have two choices on how to assign a Layer 3 ( ip ) address to a vlan / switchport.

If you want an IP address associated with a VLAN ( Default gateway ), you do the following

switch# config t
switch(config)# int vlan x ( x being your vlan )
switch(config-vlan)#ip address x.x.x.x x.x.x.x
switch(config-vlan)#no shut

What ever ports are in that vlan will use the address above as their default gateway. ( to put a port in a vlan do )

switch#
switch(config)#interface fastethernet 0/2
switch(config-interface)#switchport mode access
switch(config-interface)#switchport access vlan X = x being the vlan


If you want a switchport to act as a router port

switch#config t
switch(config)# interface fastethernet 0/1 ( or what ever )
switch(config-interface)#no switchport
switch(config-interface)#ip address x.x.x.x x.x.x.x
switch(config-interface)#no shut
switch(config-interface)#end

For DHCP, all you need to do if enable the IP Helper on the VLAN the the clients are on.

I.E if you clients are on VLAN 2,3,4 and your DHCP server is on vlan 1

switch#config t
switch(config)#interface vlan 2
switch(config)#ip helper-address x.x.x.x ( DHCP server )
switch(config)#interface vlan 3
switch(config)#ip helper-address x.x.x.x ( DHCP server )
switch(config)#interface vlan 4
switch(config)#ip helper-address x.x.x.x ( DHCP server )
switch(config)#end

Hope this helps.









LEEroy
MCNE6,CCNA2,CWNA, Project+

 

[leedsit]

God, please excuse my grammer.. bashed that email out.

LEEroy
MCNE6,CCNA2,CWNA, Project+

 

[stompin]

Ok to sort 4 vlans I would do this for all switchports I needed associated with a particular vlan...

switch#conf t
switch(config)#interface fastethernet 0/2 (whatever port)
switch(config-interface)#switchport mode access
switch(config-interface)#switchport access vlan X = x being the vlan

I now have my 4 ports in vlans 2-5, so then..

to sort the ip addresses for each vlan I would do this 4 times;

switch# config t
switch(config)# int vlan x ( x being your vlan [2-5])
switch(config-vlan)#ip address x.x.x.x x.x.x.x
switch(config-vlan)#no shut

I would then have my 4 vlans configured, each with an ip address. On a L3 switch the cross-vlan routing would then be done automatically if a packet was addressed to a host on another vlan?

I'm Ok with the DHCP and router config.

 

[leedsit]

Spot on, of course, your MLS will only route to connected networks ( the networks you configure for each vlan ), you may have to use static routers or a routing protocol on your switch to route elsewhere.

Good luck.

LEEroy
MCNE6,CCNA2,CWNA, Project+

 

[stompin]

Good man... thats simplified the process loads for me. Thanks for all your help you have been well helpful.

catch ya later

stompin

 

[leedsit]

No worries...

P.S on your MLS, you will need to switch on IP routing
switch(config)#ip routing


LEEroy
MCNE6,CCNA2,CWNA, Project+