Cisco Systems A9014CFD manual Configuring Span, Destination Interface, Traffic Types, Span Traffic

Chapter 43 Configuring Switched Port Analyzer

Configuring SPAN

Destination Interface

A destination interface (also called a monitoring interface) is a switched interface to which SPAN sends packets for analysis. You can have only one SPAN destination interface.

A destination interface has these restrictions:

•It needs to be a single physical port.

•It cannot be used as an ingress interface.

•When an interface is configured as a destination interface, it cannot be configured as a source interface.

Traffic Types

Ingress SPAN (Rx) copies network traffic received by the source interfaces for analysis at the destination interface. Egress SPAN (Tx) copies network traffic transmitted from the source interfaces. Specifying the configuration option both copies network traffic received and transmitted by the source interfaces to the destination interface.

SPAN Traffic

Network traffic, including multicast, can be monitored using local SPAN. Multicast packet monitoring is enabled by default. In some local SPAN configurations, multiple copies of the same source packet are sent to the local SPAN destination interface. For example, a bidirectional (both ingress and egress) local SPAN session is configured for sources a1 and a2 to a destination interface d1. If a packet enters the switch through a1 and gets switched to a2, both incoming and outgoing packets are sent to destination interface d1; both packets would be the same (unless a Layer-3 rewrite had occurred, in which case the packets would be different).

Configuring SPAN

The following sections describe how to configure SPAN:

•Creating a SPAN Session, page 43-4

•Removing Sources or Destination from a SPAN Session, page 43-5

Creating a SPAN Session

To create a SPAN session:

SUMMARY STEPS

1.enable

2.configure terminal

3.monitor session {session_number} type local

	Cisco ASR 901 Series Aggregation Services Router Software Configuration Guide
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