SG350: not able to ping another switch across subnets with layer 3 enabled

[AndrewKeating4493]

Here's a simplified version of some of the issue I'm having:

Switch “A” is a Cisco SG350 with layer 3 enabled and has 2 VLANs. VLAN 10 (192.168.10.0) and VLAN 20 (192.168.20.0).

Switch “B” is also a Cisco SG350 and has just the single default VLAN with an IP of 192.168.10.0 and is connected to switch A on VLAN 10.

From a host with a .10.x IP on switch B… I am able to ping a device with a .20.x IP on switch A, VLAN 20.

From a host with a .10.x IP on switch B… I am able to ping the IP of VLAN 20 on switch A.

From the web interface of switch A, VLAN 20… I am able to ping switch A, VLAN 10’s IP and hosts within it that have a properly setup gateway.

From the web interface of switch A, VLAN 20… I am able to ping hosts on switch B that have a properly setup gateway.

From the web interface of switch A, VLAN 20… I am NOT able to ping switch B’s IP address.

I can’t wrap my head around how to define a gateway for a switch’s IP, that isn’t by default the IP of itself. I feel like the above problem would be fixed if I could tell switch B that the gateway should be that of switch A, VLAN 10.

[Hector Gustavo Serrano Gutierrez]

Hi @AndrewKeating4493,

Is the Administrative Default Gateway set under Administration > Management Interface > IPv4 Interface?

[AndrewKeating4493]

That window makes perfect sense although I can't seem to find it on my GUI.

I'm running firmware v. 2.5.0.79.

Here's the closest I get to the window you are showing...

[Hector Gustavo Serrano Gutierrez]

What do you have in IP Configuration > IPv4 Management and Interfaces > IPv4 Static Routes on both of your Switches?

You have the IPv4 Routing checkbox enabled so the Routing Table filled by Static Routes should tell us where the Switch should send the traffic next for networks outside its configured VLANs.

[AndrewKeating4493]

There is no information entered in the static routing table. Is this an absolute requirement for the above scenario?

[Hector Gustavo Serrano Gutierrez]

Yes, Static Routes are required to send traffic to a next-hop for a destination outside of the VLAN/subnet.

IPv4 Static Route Setup on the 300 Series Managed Switches

Configure IPv4 Static Routes Settings on a Switch through the CLI

[AndrewKeating4493]

So if I’m trying to setup a static route between a host on switch A, VLAN 20 (eg. x.x.20.22) and the SVI of switch B (eg. x.x.10.1)…

Switch A is acting as the router so I would setup a static route with a destination of x.x.10.1 but I’m confused as to what to enter for the next hop router IP address since that would also be x.x.10.1. I try it anyways and it tells me that the "IP mask does not cover destination address".

Perhaps there’s some fundamentals I’m missing here. The info in the links you provided are informative but only give very surface information on the root purpose of some of these functions. I will read more.

[AndrewKeating4493]

There is however IPv4 Forwarding Table entries that seem to have been created by the switch upon assigning the VLANs an IP address.

Destination IP Prefix of the LANs network address to its own SVI IP address.

One for each VLAN created.

So with that in place does that tell you anything useful?