Have you configured the switch's management IP address (which is separate from its layer 3 routed interfaces) to use an IP configuration that can talk directly to its upstream connection?  It can not use itself as a default gateway.   https://documentation.meraki.com/MS/Layer_3_Switching/MS_Layer_3_Switching_and_Routing#Switch_Management_IP_and_Layer_3_Interfaces  ... View more

So, I cannot change the ip scheme of 0.0.0.1/24. But what if I on a local level crave up the /24 into /30s and then point them to the Sophos. Like 0.0.0.1/32 pointing to 0.0.0.21. This way I do not break the scheme but separate the subnets.  ... View more