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RSPAN Configuration
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2. Normal mode: To configure the RSPAN destination port in the RSPAN VLAN. Thus,
datagrams in the RSPAN VLAN will be broadcasted to the destination port. In this
mode, the destination port should be in RSPAN VLAN, and the source port should
not be configured for broadcasting storm control. TRUNK ports should be
configured carefully in order not to forward RSPAN datagrams to external
networks. The normal mode has the benefit of easy configuration, and reduced
system resources.
To be noticed: Normal mode is introduced by default. When using the normal mode,
datagrams with reserved MAC addresses cannot be broadcasted.
The number of the source mirror ports is not limited, and can be one or more.
Multiple source ports are not restricted to be in the same VLAN. The destination port and
the source ports can be in different VLAN.
For configuration of RSPAN, a dedicated RSPAN VLAN should be configured first for
carrying the RSPAN datagrams. The default VLAN, dynamic VLAN, private VLAN,
multicast VLAN, and the layer 3 interface enabled VLAN cannot be configured as the
RSPAN VLAN. The reflector port must belong to the RSPAN VLAN. The destination port
should be connected to the Monitor and the configured as access port or the TRUNK port.
The RSPAN reflector port will be working dedicatedly for mirroring, when a port is
configured as a reflector port, it will discards all the existing connections to the remote
peer, disable configurations related to loopback interfaces, and stop forwarding
datagram. Connectivity between the source and destination switch for Remote VLAN,
should be made sure by configuration.
To be noticed:
1. Layer 3 interfaces related to RSPAN VLAN should not be configured on the
source, intermediate, and the destination switches, or the mirrored datagrams may be
discarded.
2. For the source and intermediate switches in the RSPAN connections, the
native VLAN of TRUNK port cannot be configured as the RSPAN VLAN, Otherwise
the RSPAN tag will be disposed before reaching the destination switches.
3. The source port, in access or trunk mode, should not be added to RSPAN
VLAN if advanced RSPAN mode is chosen.
4. When configuring the remote mirroring function, the network bandwidth should
be considered in order to carry the network flow and the mirrored flow.
Keywards:
RSPAN: Remote Switched Port Analyzer.
RSPAN VLAN: Dedicated VLAN for RSPAN.
RSPAN Tag: The VLAN tag which is attached to MTP of the RSPAN datagrams.