[b]VLANS[/b]

dondej

I need clarification pls, just to check I have nailed this

I have hosts on different subnets in seperate vlans, after assigning a default gateway to the switch (ip of interface on router), I don't need to configure any other ip addresses for the hosts to communicate or do I?

Thanks

EdTheLad

Ok,i think you have gone a little astray.
The switch is layer 2 so it doesnt matter about a default gateway on the switch,this is only for management.
Your have created 2 vlans on your switch i will assume 1 port for vlan 2 and 1 port for vlan 3.By doing this you have isolated the layer 2 traffic between the two ports.
On your router you will create 2 subinterfaces on the interface connected to the switch,these both should be configured with the appropriate vlan i.e. subinterface 1 will have dot1q 2 and subinterface will have dot1q 3.These subinterfaces will be assigned an IP address each with an ip in the different subnet.These IP addresses are used as the default gateways on your hosts connected to the switch.
The 2 switch ports connected to your hosts should be configured as access ports and the switch port connected to the router should be a trunk port.
The trunk port must be added to both vlans 2 and 3.
So if you ping from one host to another the following will happen.

Host A will send data to the switch,the switch will receive the data on port 1 see it is a member of vlan 2 and check which other ports are members of this vlan.It will see the interface connected to the router is also a member of this vlan so data will be forwarded out towards the router with the vlan tag of 2.
The router will receive the data on the first subinterface and look for the destination network which is the second subinterface.The router will then send the data out the second subinterface towards the switch with a vlan tag of 3.The switch will receive the data see that it has a vlan tag 3 and it will then check which ports are in vlan 3.Your second host will be in Vlan 3
so the data is forwarded towards your second host.Before leaving the switch because you marked the switchport as an access port the vlan tag will be removed.If the tag was not removed your host would discard the data on arrival as it is not setup as vlan aware.

Hope that helps

dondej

That was great! Brilliantly explained

I now see where I was going wrong

Just what I needed

EdTheLad

Thanks, glad to help.

s0c0

How much VLAN stuff is covered on the exam. I have a good idea of VLAN theory and concepts, but not so much of the configurations.