Switches

Super99

I'm in the process of learning this stuff here, online training and work.
The issue is that at work we use layer3 switches and the labs are all layer 2 switches.
Also a work we have an interface for all our vlans and the labs use routers.

So my issue is that I need to unlearn everything and then learn it how labs want me to learn it
I'm so screwed!
[PHP][/PHP]

Jollycork

A switch is a switch, is a switch, except when a switch is a layer 3 switch, then a switch is a switch, is a switch which also can do routing, but a switch isn't a router, it's a switch.

Gngogh

Jollycork wrote: »

A switch is a switch, is a switch, except when a switch is a layer 3 switch, then a switch is a switch, is a switch which also can do routing, but a switch isn't a router, it's a switch.

Lol v good.

Hi. You dont have to unlearn nothing.. because a L3 switch is also a L2 switch.

bharvey92

Super99 wrote: »

I'm in the process of learning this stuff here, online training and work.
The issue is that at work we use layer3 switches and the labs are all layer 2 switches.
Also a work we have an interface for all our vlans and the labs use routers.

So my issue is that I need to unlearn everything and then learn it how labs want me to learn it
I'm so screwed!

Not sure why you have to 'unlearn' anything. A layer 3 switch is a switch that has L3 capability eg: Routing, Inter-VLAN routing. L2 switch works with MAC adddresses, L3 switch works with IP addresses.

OfWolfAndMan

Think of a L3 switch a L2 switch with extensions in both hardware and software capabilities. L3 switching is good to know, even if it's not required to pass your cert (Especially if you're managing them at work). However, looking at a couple configs and making some repetitive changes is not the same as understanding the configs line by line at a granular level where you're capable to understand traffic flows, while knowing exactly where to look where something could go wrong and what to do.

theodoxa

I think of a L3 Switch as just a combination Router + Switch. If you wanted to, you could use it as just a L2 switch, which I have seen done in some companies. You could also use it as a 24/48 Port router if you wanted to. Most importantly, you can use it as a combination of the two as you can decide what combination of switchports (L2) and routed ports (L3) you prefer.

tecnodog7

Like others mentioned a layer 3 switch is a swouter ( switch + router ) only in the sense that it can handle layer 3 functions(IP address).

bharvey92

theodoxa wrote: »

I think of a L3 Switch as just a combination Router + Switch. If you wanted to, you could use it as just a L2 switch, which I have seen done in some companies. You could also use it as a 24/48 Port router if you wanted to. Most importantly, you can use it as a combination of the two as you can decide what combination of switchports (L2) and routed ports (L3) you prefer.

That's an expensive dedicated L2 Switch you've got there

Heero

Super99 wrote: »

I'm in the process of learning this stuff here, online training and work.
The issue is that at work we use layer3 switches and the labs are all layer 2 switches.
Also a work we have an interface for all our vlans and the labs use routers.

So my issue is that I need to unlearn everything and then learn it how labs want me to learn it
I'm so screwed!

So you are literally going to unlearn Router on a stick design so you can learn how layer 3 switches work? Why not just learn both like a normal person. If you understand router on a stick design and functionality, inter-vlan routing on a layer 3 switch doesn't function much differently, you just configure it a bit differently. VLAN SVIs instead of subinterfaces on a routed port.

Super99

What I was doing wrong was getting L2 and L3 switches mixed up a bit.
At work we use L3 switches and we have all of our interfaces routed.

In L2 switches, I had to create a trunk port and then encapsulate the vlans on the router.
Here's an example.



On the switch:
interface GigabitEthernet0/1
switchport mode trunk




One the Router:
interface GigabitEthernet0/0.33
encapsulation dot1Q 33
ip address 10.63.33.254 255.255.255.0

Jollycork

tecnodog7 wrote: »

Like others mentioned a layer 3 switch is a swouter ( switch + router ) only in the sense that it can handle layer 3 functions(IP address).

I got to remember that: a swouter!!!

tecnodog7

Jollycork wrote: »

I got to remember that: a swouter!!!

Hehe I took credit for it but it's actually from Jeremy(CBT Nugget). That's how i remembered a L3

OfWolfAndMan

Also, I think you'll find it beneficial to learn about L2/L3 hybrid links as well. In the case you guys have particular VLANs spanning the whole network end to end rather than just isolated to a particular building/segment/etc.