MS250 - Static routes amd L3 routing

[Haris]

Facing issues with VLANs, as we need MS250 switches to handle the DHCP and L3 routing by itself

After configuring the VLANs we cant add static routes, only one there by default.

Because of this only one VLAN has the static route can run dhcp with internet access.

other VLANs can run dhcp but without internet

So we need to add multiple static routes.

Can anyone provide solution for this issue.

[ww]

do you mean no more default routes?

what error you get when you add  a static route?

the static routes are not for specific vlans but for the routing process of the switch. so all vlans can use them.

https://documentation.meraki.com/MS/Layer_3_Switching/MS_Layer_3_Switching_and_Routing

[Haris]

At a time only one VLAN can use the static route corresponds to the same subnet.

other VLANs worked with own dhcp range but with dns issue.

that is the reason we look to add static route for each VLAN.

Here all VLAN has own dhcp..at current only one VLAN which has one static that becomes default is working fine with dns.

when we tried to add more static route for each VLAN inorder to get proper gateway..system shows error the subnet already routed.

[ww]

all vlans are already routed if you created them on the MS L3 switch.

You just need to add the default route 0.0.0.0/0 to the next hop IP(your internet gateway/router)

[PhilipDAth]

Also note that whatever is your "default route" will also need return routes to the subnets being routed by the MS250 via the MS250.

Check out this example:

https://documentation.meraki.com/MS/Layer_3_Switching/Layer_3_Switch_Example 

[Brons2 · Accepted solution]

Exactly Philip, whatever is the next device downstream will need a static route back to any subnets that are not on the same VLAN as the connected VLAN.  If you don't give it this, then it's only going to see the VLAN that it is connected to on the Meraki.

This is assuming the devices are not using any dynamic routing protocols, of course.

[DomRod]

The concept of the Switch as layer 3 is that, you are converting your switch into a Router and the vlan interfaces as its route interfaces. All devices connected to each of the vlans configured must use the ip address of the vlan interface of the Switch connected to that vlan as their gateway. The vlan where you specified the default route 0.0.0.0/0 must be connected to the router which provides internet connection and there must be route configured on that router going to each of the subnets since subnets are now 1 hop away from the router. Also, NAT on the router must be configured to allow the translations of the ip address of each subnet.

When configured that way, all packets from any subnet destined to internet will be forwarded to the router that provides internet and the router forwards it to the destination. Now it is important to make sure that from the internet-router all devices in different subnets must be reachable or else the reply packet from the internet will not reach the host on the subnet. If you are using a modem router for internet connection, you can still configure it statistically and used the vlan interface ip of the switch where the route to 0.0.0.0/0 is configured.