Hi, They don’t need to be stacked but it may be helpful. Page 1051 [URL]
Hello, We have 2 S4048-ON switches that are currently not stacked.  We are looking at implementing VRRP on these switches for a new HA internet connection at this site.  Our current routers (SonicWALL NSA 3600) do not support VRRP and we need an intermediate device.  Since the S4048's have the capability of VRRP we hare hoping to use these instead of acquiring new routers.  So my question is, do these switches need to be stacked for this to work between them, or will this work so long as the up link between allows traffic for the vlan the vrrp is configured on? I may have other questions on configuring the routing as the isp has given us a /26 and a /29 where the /26 uses an ip of the /29 for the gateway.
S4048-ON VRRP between two un-stacked switches