Solved: Re: Ping issue between client and vlan

joedytay94 · ‎08-13-2023

As per the diagram, I have two vlans (1 and 30). The server in vlan 30 is able to ping all the ip addresses in the diagram but the pc in vlan 1 is unable to

ping 30.30.30.254

What could be the reason it's unable to do so? I assume the routing is okay since the PC can ping the server and the

ip 30.30.30.253

I would very much like the PC to be able to

ping 30.30.30.254

so I can remotely access it from vlan1.

Flavio Miranda · ‎08-13-2023

Hi @joedytay94

PC is able to ping server because switch 1 has

ip routing

and interface vlan on both vlans. But switch 2 only knows network

30.30.30.0

When a packet comes from PC network it does not know what to do.

You need to add a

static/default route

on switch 2 sending the traffic back to switch 1

Conf t

 ip route 0.0.0.0 0.0.0.0 30.30.30.253

View solution in original post

Flavio Miranda · ‎08-13-2023

Hi @joedytay94

PC is able to ping server because switch 1 has

ip routing

and interface vlan on both vlans. But switch 2 only knows network

30.30.30.0

When a packet comes from PC network it does not know what to do.

You need to add a

static/default route

on switch 2 sending the traffic back to switch 1

Conf t

 ip route 0.0.0.0 0.0.0.0 30.30.30.253

joedytay94 · ‎08-13-2023

Thanks for the help Flavio! I can finally ping the

ip 30.30.30.254

I have a few questions I would like to further ask, would adding a static route e.g

ip route 8.0.0.0 255.0.0.0 30.30.30.253

work the same way too? Also, can I do routing between both networks if I don't set vlan's for both network by connecting both switches with an ethernet cable?

I've always been under the impression that since Layer 3 switches can do routing, it can route between different networks without it being in seperate vlans (intervlan routing). However, so far all the articles I've read online relates Layer 3 Switch routing to intervlan routing.

Flavio Miranda · ‎08-13-2023

@joedytay94 , let me coment on you comments

"Thanks for the help Flavio! I can finally ping the

ip 30.30.30.254

I have a few questions I would like to further ask, would adding a static route e.g

ip route 8.0.0.0 255.0.0.0 30.30.30.253

work the same way too?"

Yes. It is another solution. But, if you add a third network, you need to repeat the process for every network. By using

0.0.0.0 0 0.0.0.0

you are meaning everything.

"Also, can I do routing between both networks if I don't set vlan's for both network by connecting both switches with an ethernet cable?"

Only in layer2 not possible. Vlans are separated broadcast domains.

in order to communicate between vlans you need to have layer3 either on the switch by adding interface vlan and

ip routing

or you use a router

"I've always been under the impression that since Layer 3 switches can do routing, it can route between different networks without it being in seperate vlans (intervlan routing).

It is able just like any other layer3 device. But, for example, if you had layer3 interfaces(interface with ip address).

As soons as you create interface vlan, you are creating layer2 and layer3. For this case, InterVLAN routing is required.

"However, so far all the articles I've read online relates Layer 3 Switch routing to intervlan routing."

For the reason I memtioned above. Layer3 switch can iinclusive support dynamic routing protocol like bgp,ospf,etc.

But in order to Carrier traffic between vlans, you need to have Interface vlan configured and InterVLAN routing enable.

joedytay94 · ‎08-13-2023

Yes. It is another solution. But, if you add a third network, you need to repeat the process for every network. By using

0.0.0.0.0 0.0.0.0

you are meaning everything.

- I get what you mean. For

0.0.0.0

it eliminates the need to static route for each individual network.

"Also, can I do routing between both networks if I don't set vlan's for both network by connecting both switches with an ethernet cable?"

Only in layer2 not possible. Vlans are separated broadcast domains.

in order to communicate between vlans you need to have layer3 either on the switch by adding interface vlan and

ip routing

or you use a route.

- Apologies for not being clear. I meant if both the

8.12.5 network and 30.30.30

network are in vlan1 on their respective layer 3 switches, can I still route them between each other by configuring static route on both layer 3 switches?

Flavio Miranda · ‎08-13-2023

I got it. And no, they dont.

If you create interface vlan 1 assign

ip address 8.x.x.x

in switch 1 then you go to switch 2 and create interface vlan1 and assign

ip address 30.x.x.x

they will not communite.

Because in order to a device send a packet to another network, it is required a gateway and on this case there would not exist a gateway.

It would be possible if you create a layer3 point to point between switches.

Enable

ip routing

and use the layer3 interface or the neighbor ip address as gateway

joedytay94 · ‎08-13-2023

I see, would you be able to show me an example of what you mean by create a layer 3 point to point between the switches? Does that mean I have to have another layer 3 switch between the two switches to do the routing?

Flavio Miranda · ‎08-13-2023

Not possible is all switches but you can try

conf t

 interface gix/x or fx/x

no switchport

 ip address x.x.x.x  x.x.x.x

end

Do it on both switches and put both interface on the same network

You'll be creating a layer3 point to point.

joedytay94 · ‎08-13-2023

I got it to work with your command. Now I finally understand how to do it! I've always wanted to do all the routing of multiple network just on a Layer 3 switch so I don't have to use an extra router. Thanks for the advice Flavio!

Flavio Miranda · ‎08-13-2023

You are welcome @joedytay94

Keep going with you study.