So that jpscharf's point doesn't get lost in threads:
If you are running macOS Sequoia, there's a good chance you need to enable Local Network access under System Settings -> Privacy & Security -> Local Network. Make sure that Google Chrome is turned on, as well as any other third-party browsers you use.
Normally, you get ask for this permission upon first launch of Google Chrome, but it's easy to hit the wrong key and dismiss it.
ICMP does not use ports, so it's not working as tcp or udp would.
Check whether the target host allows incoming tcp/udp connections.
Also, because of the IP range you posted: If you are using a VPN, the client could be misconfigured. It could be that the VPN client is e.g. exposing a local SOCKS or HTTP/HTTPS proxy that Chrome ignores.
So that jpscharf's point doesn't get lost in threads:
If you are running macOS Sequoia, there's a good chance you need to enable Local Network access under System Settings -> Privacy & Security -> Local Network. Make sure that Google Chrome is turned on, as well as any other third-party browsers you use.
Normally, you get ask for this permission upon first launch of Google Chrome, but it's easy to hit the wrong key and dismiss it.
ICMP does not use ports, so it's not working as tcp or udp would.
Check whether the target host allows incoming tcp/udp connections.
Also, because of the IP range you posted: If you are using a VPN, the client could be misconfigured. It could be that the VPN client is e.g. exposing a local SOCKS or HTTP/HTTPS proxy that Chrome ignores.
If you are running Sequoia, check your macOS security settings (System Settings > Privacy & Security > Local Network).
chrome://settings/content/siteDetails?site=http%3A%2F%2F10.78.16.30
Sadly, even at its most permissive, the site is still ERR_ADDRESS_UNREACHABLE (which to me implies it's lower down Chrome's network stack).
If you make a Chrome bookmark pointing to the subnet address it always works.
I would file a bug. Instructions are here: https://www.chromium.org/for-testers/bug-reporting-guideline...
As a workaround, you could try adding this IP address to /etc/hosts as foobar.home.arpa or whatever, and see if that works better.