Network getting down on SG-300

[shijujacob93]

Hi all,

Please take a look at the attachment. When I plug a cable coming from another switch with vlan  10.1.40.xxx to the vlan 20 of sw1 , my network with 192.168.128.xxx  of sw2 goes down. When i unplug the cable it works again.

can anyone help me/

[Deepak Kumar]

Hi, 

I am not sure, how did you configure all ports and routing? But as per your diagram, it is looking the issue of an overlapping subnet.

Steps to check resolve issue:

1. Is the IP routing command enabled on both switches?

2. If Yes, then remove IP routing command from one switch and verify hosts default gateway for 192.168.128.xxx subnet, it must be svi IP of the switch where IP routing enabled.

If not possible above:- 

Final advised changing a subnet form 192.168.128.xxx to another on any of switch.

Regards,

Deepak Kumar

[shijujacob93]

Hi,

I'm not sure about the configuration on SW2, since it's not accessible to me. 

i

I want some devices on my SW1 with IP 192.168.128.xxx to communicate with both network (SW2 192.168.128.xxx and network on another switch with 10.1.40.xxx). So I configured SW1 for two Vlans and turned on inter vlan routing , and connected SW2 to vlan 1 of SW1 and SW3(10.1.40.xxx) to Vlan 20 of SW1.

During that time Im able to access SW3 from SW1. But not SW2 from SW1

What is the simplest way to do