SPAN Simple Learning

SPAN Simple learning SPAN allows any port of the switch or traffic on any VLAN to be copied and sent to any other port. The source of a SPAN can be a physical interface or VLAN, and multiple physical interfaces or VLANs can be defined. The replication traffic can be unidirectional or bidirectional, while the SPAN traffic can only be physical interfaces or VLANs. When an interface is defined as a SPAN target interface, it cannot accept any other normal traffic. When the source and destination of a SPAN are on the same vswitch, it is called a local span, that is, a SPAN. When the source and destination are not on the same vswitch, it is called a remote span, or RSPAN. When implementing RSPAN, the traffic copied by SPAN must be sent to a VLAN and then uploaded from the TRUNK to the target switch. This VLAN is called the rsapn vlan, the rspan vlan must be configured on each switch from the source to the target. When implementing RSPAN, On the Source switch, the source of SPAN is defined as a physical interface or VLAN. The destination must be defined as an rspan vlan rather than a physical interface. On the target switch, define a SPAN lake as a rspan vlan and define the objective as a physical interface. In some IOS versions, when defining a target, the source switch must not only define the rspan vlan as the target, but also specify a reflector ctor-port, the system sends the traffic to the reflector-port and then the reflector-port to the rspan vlan. When an interface is configured as reflector-port, this interface cannot be used normally. When SPAN is implemented, the following restrictions are imposed: 1. A vswitch supports a maximum of two SPAN sessions. 2. A maximum of 64 target ports are supported, the source port has no upper limit. Layer 3 interfaces can also be used as the source or destination. 4. The source and target rates must be consistent. 5. If a target port is in the source VLAN, 6. If the source port is TRUNK, all VLAN traffic will be copied, but some VLANs can be filtered, only the VLAN traffic in the List will be copied. 7. When a SPAN interface is configured for an interface, all configurations disappear. After the SPAN is disabled, the configuration is restored. 8. The target cannot be a security port or a source; it cannot be an etherchannel group or a normal vlan9 or a target port. It cannot be the target of two sessions.