Monitored Traffic; Erspan Types - Cisco Nexus 5600 Series Configuration Manual

Monitored Traffic

• An ERSPAN flow ID.
• Optional attributes related to the GRE envelope such as IP TOS and TTL.
• Destination IP address.
• Virtual Routing and Forwarding tables.
ERSPAN source sessions do not copy ERSPAN GRE-encapsulated traffic from source ports. Each ERSPAN
source session can have ports, VLANs, or VSANs as sources. However, there are some limitations. For more
information, see Guidelines and Limitations for ERSPAN.
The following figure shows an example ERSPAN configuration.
Figure 1: ERSPAN Configuration
Monitored Traffic
By default, ERSPAN monitors all traffic, including multicast and bridge protocol data unit (BPDU) frames.
The direction of the traffic that ERSPAN monitors depends on the source, as follows:
• For a source port, the ERSPAN can monitor ingress, egress, or both ingress and egress traffic.
• For a source VLAN or source VSAN, the ERSPAN can monitor only ingress traffic.

ERSPAN Types

Cisco NX-OS Release 7.1(1)N1(1) supports two types of ERSPAN—ERSPAN Type II (default) and ERSPAN
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.
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latency among edge, aggregate, and core switches.
Configuring ERSPAN
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