Cisco Nexus 3548 - ERSPAN Sources; ERSPAN Destinations; ERSPAN Sessions

ERSPAN Sources
The interfaces from which traffic can be monitored are called ERSPAN sources. Sources designate the traffic
to monitor and whether to copy ingress, egress, or both directions of traffic. ERSPAN sources include the
following:
•
Ethernet ports and port channels.
• VLANs—When a VLAN is specified as an ERSPAN source, all supported interfaces in the VLAN are
ERSPAN sources.
ERSPAN source ports have the following characteristics:
•
A port configured as a source port cannot also be configured as a destination port.
•
ERSPAN does not monitor any packets that are generated by the supervisor, regardless of their source.
ERSPAN Destinations
ERSPAN destination sessions capture packets sent by ERSPAN source sessions on Ethernet ports or port
channels and send them to the destination port. Destination ports receive the copied traffic from ERSPAN
sources.
ERSPAN destination sessions are identified by the configured source IP address and ERSPAN ID. This allows
multiple source sessions to send ERSPAN traffic to the same destination IP and ERSPAN ID and allows you
to have multiple sources terminating at a single destination simultaneously.
ERSPAN destination ports have the following characteristics:
•
A port configured as a destination port cannot also be configured as a source port.
•
Destination ports do not participate in any spanning tree instance or any Layer 3 protocols.
•
Ingress and ingress learning options are not supported on monitor destination ports.
•
Host Interface (HIF) port channels and fabric port channel ports are not supported as SPAN destination
ports.
ERSPAN Sessions
You can create ERSPAN sessions that designate sources and destinations to monitor.
When configuring ERSPAN source sessions, you must configure the destination IP address. When configuring
ERSPAN destination sessions, you must configure the source IP address. See ERSPAN Sources, on page
160 for the properties of source sessions and ERSPAN Destinations, on page 160 for the properties of destination
sessions.
Only eight unidirectional, or four bidirectional ERSPAN or SPAN source sessions can run simultaneously
across all switches. Only 20 ERSPAN destination sessions can run simultaneously across all switches.
Note
Cisco Nexus 3548 Switch NX-OS System Management Configuration Guide, Release 6.x
160
Configuring ERSPAN
ERSPAN Sources