is the subletting the default gateway when running on a stick?

[WIZARD1325]

I can get my computers to ping for crap

[Julio E. Moisa]

Hi

Please correct me if I am not understanding the question, but the default gateway is configured on the layer 3 devices like routers, multilayer switches or firewalls. So if you have a router-in-a-stick scheme the gateway for your computer will be installed/configured on the router (sub-interface).

:-)

[WIZARD1325]

Im trying to figure out why my computers wont ping the other vlan.

Is it something in the host under static ip im putting wrong under default gateway.

But on the stick the router has no ip

Im so lost ahhhhh

[Rafael Carvallo]

Hi,

I'll try to help little bit:

1.- Routing on a stick is basically a topology where you connect a switch and a router via a trunk interface

2.- The switch will only do L2 (switching), so, in case VLAN A wants to talk to VLAN B it must send the traffic towards the router

3.- The IPs in the router must be in the sub-interfaces, unless you're also routing the native vlan which is untagged (in which case the IP is set directly in the interface itself)

In your router you must have a series of sub-interfaces with the proper vlan tagging so lets elaborate a small scenario:

VLAN 10 - Subnet 192.168.10.0/24

VLAN 20 - Subnet 192.168.20.0/24

The gateway being the first IP of each subnet as in 192.168.10.1 and 192.16.20.1 respectively 

Assume your router's interface towards the switch is called g1/0/1

Assume your switch's interface towards the router is also called g1/0/1, assume g1/0/2 is for a PC in vlan 10 and g1/0/3 is for a PC in vlan 20

You'd do this on your switch:

vlan 10
vlan 20
interface g1/0/1
 description connection to Router
 switchport mode trunk
interface g1/0/2
 description connection to PC on VLAN10
 switchport mode access
 switchport access vlan 10
interface g1/0/3
 description connection to PC on VLAN20
 switchport mode access
 switchport access vlan 20

next in your router you'd 

interface g1/0/1.10
 encapsulation dot1q 10
 ip address 192.168.10.1
interface g1/0/1.20
 encapsulation dot1q 20
 ip address 192.168.20.1
interface g1/0/1
 no shutdown

Notice how the subinterfaces were created, I added a dot plus a number to the physical interface name, then it goes into sub-interface mode configuration where I set up what's the VLAN tag tied to this sub-interface and the IP. This basically is telling the router "when you see a frame with VLAN 10 over g1/0/1 assume it's in 192.168.10.0/24 and if you want to communicate with 192.168.10.0/24, send it over g1/0/1 with a vlan tag of 10"

Your PCs on VLAN 10 would need an IP from 192.168.10.0/24 except 192.168.10.1 (the gateway) like this:

IP: 192.168.10.10

mask: 255.255.255.0

gateway: 192.168.10.1

The PCs on VLAN 20 would need IPs from 192.168.20.0/24, again except the first one like this:

IP: 192.168.20.10

mask: 255.255.255.0

gateway: 192.168.20.1

HTH

Please remember to rate useful posts

[WIZARD1325]

Nope that didnt work ethier

 still cant ping

subnet mask keeps saying bad mask/24 for the ip address you've given

WTF nothing is WORKING ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

im so getting fustrated been a week now and i can figure this poop out!!!!!

[Julio E. Moisa]

Hi

You need a L3 devices to enable the communication between VLANs. Now for example if you have 2 VLANs configured on a layer 2 switch like 2960 switch, and 2 computers are connected to ports with different VLANs, they will not able to communicate between them until you install a L3 device where the gateways will be configured. 

By default a L3 device will allow the communication between the networks created locally. 

:-)

[WIZARD1325]

I did all that

[Julio E. Moisa]

Hi

Have you disabled the window firewall? or are you using packet tracer?

[WIZARD1325]

anybody want to teamviewer with me and watch me

so they can tell me what my malfunction is?

\

[Julio E. Moisa]

Hi,

Could you please share a picture of how is built your topology? in order to know how to fix the trouble. 

[WIZARD1325]

switch

10 apples active Fa0/1

20 pears active Fa0/2

Port 24 to router trunked

router

interface FastEthernet0/0.10

encapsulation dot1Q 10

ip address 192.168.10.1 255.255.255.0

interface FastEthernet0/0.20

encapsulation dot1Q 20

ip address 192.168.20.1 255.255.255.0

[Julio E. Moisa]

Hi

Your configuration looks fine, now the problem could be:

1- The computers have not configured the proper default gateway IP (vlan 10 the gateway is 192.168.10.1 and for vlan 20 192.168.20.1)

2- If you are trying on real device, check the windows firewall or antivirus and disable them.

Also you could verify if you can ping the gateways. for example:

Computer 1

ping 192.168.10.1 

ping 192.168.20.1

Do the same with the computer 2.

Hope it is useful

:-)

[WIZARD1325]

I triple  checked and im using packet tracers

Cant ping anybody still

am  i suppose to set ips to the switch?

i saw a youtube video that did that

but says nothing in the instructions to do that?

[Julio E. Moisa]

Hi,

Could you please share a picture of the topology and the port configurations on the switch and router. 

Thank you in advance.

[Skywalker]

Hello,

For starters, can you ping the PCs from the router and vise versa?

__
Regards,