If I am sitting at the command line of a host and have an IP and port for a destination, is there any way to tell if the network path involves a firewall, or if it's being evaluated by a ruleset of some kind? I assume there's no way to tell because a network path that's not dropped (that's allowed by a firewall ruleset) would appear exactly the same as a network path with no firewall evaluation involved, but looking to confirm that.
Maybe more generally, is a firewall always involved (at some level) when I have multiple VLANs on my network, or could traffic route between VLANs (with different gateway IP addresses) without being evaluated by firewall rules?
I'm trying to determine how early to involve our InfoSec team in troubleshooting efforts when we lose connectivity - in some cases, we're crossing VLAN boundaries but the two different VLANs have open access to each other (all traffic allowed). Does this have to be configured by a firewall (and a ruleset), or is it possible that the switches can be configured to consider this traffic open (traversing VLAN without a firewall)?