If I understand ,Cisco Switches have VLAN 1 as the default native Vlan.
Many resources say that leaving Native VLAN to VLAN 1, can be security breach.
1- Can someone explain why leaving VLAN 1 can be security breach ?
2- If I need to change Native VLAN 1 to VLAN 777, I believe this is done at the Interface Level. Does that mean I need to go to each switch and change the interfaces that are in VLAN1 to VLAN 777 ?
3- if some switches Native VLAN is VLAN1 and some is VLAN 777, does that mean traffic coming from those Native Vlans will be forwarding to all ports on the switch...
in other words if a PC is connected to Native Vlan , will be able to ping another PC which is connected to VLAN 33 and the other way around is also True?