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Why are trunk ports necessary?
A trunk port allows you to send all those signals for each switch or router across a single trunk link. In contrast to an access port, a trunk port must use tagging in order to allow signals to get to the correct endpoint. Trunk ports typically offer higher bandwidth and lower latency than access ports.
Do all switches have a trunk port?
Cisco switches have two Ethernet trunking mechanisms: ISL and IEEE 802.1Q. Certain types of switches can negotiate trunk links. Trunks carry traffic from all VLANs to and from the switch by default but can be configured to carry only specified VLAN traffic.
What does Rspan stand for?
Port mirroring on a Cisco Systems switch is generally referred to as Switched Port Analyzer (SPAN) or Remote Switched Port Analyzer (RSPAN). Other vendors have different names for it, such as Roving Analysis Port (RAP) on 3Com switches.
What’s the difference between remote span and RSPAN?
Remote SPAN (RSPAN) Remote SPAN (RSPAN) is similar to SPAN, but it supports source ports, source VLANs, and destination ports on different switches, which provide remote monitoring traffic from source ports distributed over multiple switches and allows destination centralize network capture devices.
What kind of traffic does the RSPAN VLAN carry?
The RSPAN VLAN carries SPAN traffic between RSPAN source and destination sessions. It has these special characteristics: All traffic in the RSPAN VLAN is always flooded. No MAC address learning occurs on the RSPAN VLAN. RSPAN VLAN traffic only flows on trunk ports.
What happens when RSPAN source session is disabled?
Any device that is connected to a port that is set as a reflector port loses connectivity until the RSPAN source session is disabled. If the bandwidth of the reflector port cannot handle the traffic from the corresponding source ports, the excess packets are dropped. A 10/100 port reflects at 100 Mbps.
How are RSPAN sessions transported across multiple switches?
Each RSPAN session carries the SPAN traffic over a user-specified dedicated RSPAN VLAN in all participating switches. This VLAN is then trunked to other switches, allowing the RSPAN session traffic to be transported across multiple switches and delivered to destination capturing station.