VLAN Question

bankintheroll

I created a little VLSM network on Packet Tracer. I setup a router connected to a switch, then another switch connected to that switch, with a few PCs on each switch.

I can get every PC to ping each other and to the router, and vice versa, but I can't ping the switches. The IP on the switches is on VLAN 1. I created 2 VLANs, 10 and 20. Do I need to create an IP on each virtual switch interface to be able to ping? Or am I doing something wrong? Or do you even need to be able to ping switches from PCs?

Also, I don't have an interface IP on the router, just virtual interface IPs.

martell1000

"The IP on the switch is on VLAN 1. I created 2 VLANs, 10 and 20."

the ip your pinging from needs to be in vlan1 or have a route to reach vlan1

is you inter vlan routing to vlan 1 correct?

EdTheLad

You only need to be able to ping the switches if you want to manage them remotely via ip rather than via console. To do this normally you would create a separate vlan for management, lets say vlan 100, create a subinterface .100 on the router with an ip address in the management subnet. Allow vlan 100 on the trunk between router and switch and between switches. Configure a vlan 100 on all switches along with the corresponding svi with management ip address. All management addresses in vlan 100 will be part of the same subnet.

bankintheroll

Good point. Thank you for that.

bankintheroll

So, if all routers and PCs can ping each other, does the switch even need a default gateway? I would think not, because the router just has virtual interfaces and not an IP on the physical interface.

Sorry for my ignorance guys. I haven't even taken my CCENT yet, but am trying my damnedest to teach myself.

EdTheLad

You only need a default gateway if the switch needs to communicate to an ip address off the local subnet. The default gateway would point to a router, the router will then route between the different subnets.

bankintheroll

Okay, so if I connect a 2nd router to the 1st one via serial, I would need a default IP when PCs from the 1st router talk to PCs connected to the 2nd router?

Sorry, this is probably such a simple concept, but I got kind of confused putting together a network of VLANs and subnets using VLSM.

martell1000

you need to ensure that you have routing enabled between the VLANs this is either done by configuring a "router on a stick" or L3 switching

"router on a stick" is what Ed pointed out with creating sub interfaces to ensure routing but that concept is rather outdated in the real world - so you need some L3 switching How To Configure InterVLAN Routing on Layer 3 Switches - Cisco

read this and if you have any questions feel free to ask

EdTheLad

Yes, since routers have a different subnet per interface, if you need to communicate off subnet you need a default gateway.

broli720

martell1000 wrote: »

you need to ensure that you have routing enabled between the VLANs this is either done by configuring a "router on a stick" or L3 switching

"router on a stick" is what Ed pointed out with creating sub interfaces to ensure routing but that concept is rather outdated in the real world - so you need some L3 switching How To Configure InterVLAN Routing on Layer 3 Switches - Cisco

read this and if you have any questions feel free to ask

You're basically creating interfaces on your respective vlans and enabling routing on the switch.

EdTheLad

martell1000 wrote: »

"router on a stick" is what Ed pointed out with creating sub interfaces to ensure routing but that concept is rather outdated in the real world - so you need some L3 switching How To Configure InterVLAN Routing on Layer 3 Switches - Cisco

I think he should learn the basic concepts of routing and switching individually before he starts looking at l3 switches. Routing on a stick is an important concept in the ccna, l3 switches is more a ccnp topic.

bankintheroll

Thank all of you so much for your help! I'm going to get router-on-a-stick down before anything else, but also read some more on layer 3 switching.

I am also going to connect another router, and try both static routing and OSPF between those 2.

I'll come back if I have anymore questions. This place is great and you guys are awesome for taking the time to help people like me!

martell1000

EdTheLad wrote: »

I think he should learn the basic concepts of routing and switching individually before he starts looking at l3 switches. Routing on a stick is an important concept in the ccna, l3 switches is more a ccnp topic.

didnt they put l3 switching in the new ccna? but i agree he should get the concepts first (and i admit that the term "router on a stick" still makes me think of food )

EdTheLad

No idea, just think of when i did ccna, i hate the term "routing on a stick", sounds so silly to me, i only use it on this website.

martell1000

at least it STICKS to the head because it sounds so stupid