VLans communication with Router

[Daud Tajik]

I have Cisco Layer 3 Switch 3860 with 12 SFP ports (no ethernet), connected with Cisco 2960 switch and a Router Cisco 2911.

Currently I have created 4 VLans i.e. 10 (10.1.10.0 / 255.255.255.128), 20(10.1.20.0), 30(10.1.30.0) & 40(192.168.2.0 / 255.255.255.0) on Switch 3860.  The router & servers are connected with Switch 2960. Router & Servers Lan interface ip is from 192 subnet.

On Switch 3860 i have configured Interface 10, 20, 30 & 40 IP addresses that are also the gateway for computers means Inter-VLAN communication or IP routing for VLans are configured on L3 Switch 3860.

Now how can I communicate the Lan with the router

[Carlos Villagran · Accepted solution]

The 2960 switch must be configured with the same vlans as the 3860 and with a trunk interface between them allowing those vlans to traverse over the trunk.

Best regards.

JC

[Daud Tajik]

Dear Carlos, you have not understood my question? OK, my Lan users are connected with Layer 3 switch because i have done routing and inter-vl

[Carlos Villagran]

Hi Daud!

I am really really sorry, correcting my answer, what I would do will be create a layer 3 link between your switch who is doing the inter-vlan routing and the router instead of placing it in the vlan 40 (192.x.x.x).

In the interface configuration mode, use the no switchport command, and add an IP address, you can then add a default route in the switch ponting to the router or using a routing protocol between your multilayer switch and the router.

Hope it helps, best regards!

JC

[Daud Tajik]

unfortunately in my case the router is connected with L2 switch not with L3 because L3 has only SFP ports and router doesn't have SFP.

no switchport command is not supported in L2 even i use ip routing

Now whats the solution

[Daud Tajik]

Still waiting for the reply

[Carlos Villagran]

Hi Daud!

I am not quite sure of the topology yet to be honest. What I understand is that you have your LAN users connected to the L3 switch and this switch is connected to a L2 switch connected, this L2 switch is connected to a router and what you are trying to do is to take the traffic of your users to traverse the L2 switch and reach the router, however you are doing intervlan routing in the L3 switch.

         intervlan-r
            +------+  +--+
            | L3   +--+--+
            +---+--+  +--+
                |    users
                |
             +--+--+
             | L2  |2960
             +--+--+
                |
                |
             xxx+xx
            xx    x
            xx R1 x
             xxxxxx

If this is true, then as a solution you can put the router in vlan 1 or any other vlan common for both switches and add a default route pointing to the router interface.

L3 switch will be able to reach it and any VLAN trying to get out of the LAN will be routed to the VLAN (SVI) in switch L3 and then to the router.

If this topology is not correct, please let me know and I will help with a solution! Sorry for the delay.

Best regards!

JC