Configuring Erspan; About Erspan; Erspan Types; Erspan Sources - Cisco Nexus 7000 Series Configuration Manual

About ERSPAN

About ERSPAN
ERSPAN transports mirrored traffic over an IP network, which provides remote monitoring of multiple
switches across your network. The traffic is encapsulated at the source router and is transferred across the
network. The packet is decapsulated at the destination router and then sent to the destination interface.

ERSPAN Types

Cisco NX-OS Release 6.1 and later releases support ERSPAN Type II and Type III. All previous Cisco NX-OS
releases support only ERSPAN Type II.
ERSPAN Type III supports all of the ERSPAN Type II features and functionality and adds these enhancements:
• Provides timestamp information in the ERSPAN Type III header that can be used to calculate packet
• Identifies possible traffic sources using the ERSPAN Type III header fields.
• Provides the ability to configure timestamp granularity across all VDCs to determine how the clock

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.
• The inband interface to the control plane CPU—You can monitor the inband interface only from the
• VLANs (ingress only)—When a VLAN is specified as an ERSPAN source, all supported interfaces in
• Fabric port channels connected to the Cisco Nexus 2000 Series Fabric Extender (FEX).
• Satellite ports and host interface port channels on the Cisco Nexus 2000 Series Fabric Extender— These
Note Layer 3 subinterfaces are not supported.
A single ERSPAN session can include mixed sources in any combination of the above.
Note
See the Cisco Nexus 7000 Series NX-OS Verified Scalability Guide for information on the number of supported
ERSPAN sessions.
ERSPAN source ports have the following characteristics:
Cisco Nexus 7000 Series NX-OS System Management Configuration Guide
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latency among edge, aggregate, and core switches.
manager synchronizes the ERSPAN timers.
default virtual device context (VDC). Inband traffic from all VDCs is monitored.
the VLAN are ERSPAN sources.
interfaces are supported in Layer 2 access mode, Layer 2 trunk mode, and Layer 3 mode.

Configuring ERSPAN