Can someone please help me understand this access list for the VTY lines? Previous network engineer has this in our switches on the VTY lines, the part I don't quite understand is the host 0.0.0.0? It's been working and then a few of our switches rebooted then we were not able to SSH in and I had to remove the host 0.0.0.0 and add in "any" but not sure why?
The ACE indicates that packets with source 192.168.0.0 and with destination the default network, through port 22 will be allowed. When changing the destination to any, the packets that reach the vty lines with any destination, through port 22 will be allowed.
You must be clear about what you are looking for with the ACL. My recommendation is that the source of the allowed packets is not so wide, moreover, it should be only a very limited range of IPs, as that will contribute to the security of your network.