1

Hi guys

I’m currently facing some difficulties to access the internet on one of my vlan’s.

Here is my setup:

I’ve got a internet router (ISP) = 192.168.1.1

With a cat5 cable I’ve connected my router to my layer3 switch= 192.168.1.20.

Below I listed some screesnhots of the IPv4 Interface and the routing.

interface_.jpg

ipv4_routes.jpg
ipv4_routes.jpg800×204 24 KB

After the configuration of my vlan2 I set up dhcp server with the following settings:

dhcp.jpg
dhcp.jpg734×896 65.6 KB

My issue is that I get a ip adress and the configured options from the dhcp-server but I’m unable to access the internet. I’ve set up a static route and can succesfully ping the 192.168.1.x network from my vlan2= 192.168.2.0 network.

Do you guys have any idea what could causing this problem.

On the client side on the network adapter on the connectivity status: No Internet Access.

If I do a tracert to 8.8.8.8 from the client after two hops:

192.168.2.20

and 192.168.1.1 I get multiple timed out lines…

Thanks for any hint and idea.

Greetings

Abdi

6 Spice ups
2

The problem is that the ISP router does not know that it needs to send traffic for 192.168.2.c to the layer 3 switch. You need to put a route into the ISP router.

3 Spice ups
3

Also, if you want your 192.168.2.0/24 DHCP clients to have internet access you need to configure the default gateway in DHCP option 3.

3 Spice ups
4

Thanks for your reply. I’ve setup the following route on my ISP router.

routing.jpg
routing.jpg800×91 6.22 KB

Do I need maybe to setup another route, because from the 192.168.1.x I can reach the 192.168.2.x and vice versa.

5

I’ve defined the default gateway as my isp router= 192.168.1.1 but got the same result.

@dreid007 @lewpaceley

6

Yes, you do need a route in each direction. Routes are unidirectional.

You’ll have two routes, one from the 192.168.2.0/24 subnet to the 192.168.1.0/24 subnet and one from the 192.168.1.0/24 subnet to the 192.168.2.0/24 subnet.

7

The default gateway must be within the same network as the device. This means that for vlan2 you need to use 192.168.2.20 (your L3 switch).

8

Also, the L3 switch port that is connecting your ISP router to the switch needs to have an IP address in the 192.168.1.0/24 subnet such as 192.168.1.2 since your ISP gateway is 192.168.1.1

On a Cisco L3 switch the commands would be something like this for Gigabit switch port 20:

interface Gi0/20

no switchport

ip address 192.168.1.2 255.255.255.0

no shutdown

I’m a little rusty on the configs, but hopefully you get the idea.