user manual

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A private-VLAN port cannot be a SPAN destination port.
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A secure port cannot be a SPAN destination port.
For SPAN sessions, do not enable port security on ports with monitored egress when ingress forwarding
is enabled on the destination port. For RSPAN source sessions, do not enable port security on any ports
with monitored egress.
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An IEEE 802.1x port can be a SPAN source port. You can enable IEEE 802.1x on a port that is a SPAN
destination port; however, IEEE 802.1x is disabled until the port is removed as a SPAN destination.
For SPAN sessions, do not enable IEEE 802.1x on ports with monitored egress when ingress forwarding
is enabled on the destination port. For RSPAN source sessions, do not enable IEEE 802.1x on any ports
that are egress monitored.
SPAN and RSPAN and Device Stacks
Because the stack of switches represents one logical switch, local SPAN source ports and destination ports
can be in different switches in the stack. Therefore, the addition or deletion of switches in the stack can affect
a local SPAN session, as well as an RSPAN source or destination session. An active session can become
inactive when a switch is removed from the stack or an inactive session can become active when a switch is
added to the stack.
Flow-Based SPAN
You can control the type of network traffic to be monitored in SPAN or RSPAN sessions by using flow-based
SPAN (FSPAN) or flow-based RSPAN (FRSPAN), which apply access control lists (ACLs) to the monitored
traffic on the source ports. The FSPAN ACLs can be configured to filter IPv4, IPv6, and non-IP monitored
traffic.
You apply an ACL to a SPAN session through the interface. It is applied to all the traffic that is monitored
on all interfaces in the SPAN session.The packets that are permitted by this ACL are copied to the SPAN
destination port. No other packets are copied to the SPAN destination port.
The original traffic continues to be forwarded, and any port, VLAN, and router ACLs attached are applied.
The FSPAN ACL does not have any effect on the forwarding decisions. Similarly, the port, VLAN, and router
ACLs do not have any effect on the traffic monitoring. If a security input ACL denies a packet and it is not
forwarded, the packet is still copied to the SPAN destination ports if the FSPAN ACL permits it. But if the
security output ACL denies a packet and it is not sent, it is not copied to the SPAN destination ports. However,
if the security output ACL permits the packet to go out, it is only copied to the SPAN destination ports if the
FSPAN ACL permits it. This is also true for an RSPAN session.
You can attach three types of FSPAN ACLs to the SPAN session:
• IPv4 FSPAN ACL— Filters only IPv4 packets.
• IPv6 FSPAN ACL— Filters only IPv6 packets.
• MAC FSPAN ACL— Filters only non-IP packets.
The security ACLs have higher priority than the FSPAN ACLs on a switch. If FSPAN ACLs are applied, and
you later add more security ACLs that cannot fit in the hardware memory, the FSPAN ACLs that you applied
are removed from memory to allow space for the security ACLs. A system message notifies you of this action,
which is called unloading. When there is again space for the FSPAN ACLs to reside in memory, they are
Catalyst 2960-X Switch Network Management Configuration Guide, Cisco IOS Release 15.0(2)EX
76 OL-29044-01
Configuring SPAN and RSPAN
Flow-Based SPAN