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Catalyst 3750 Switch Software Configuration Guide
OL-8550-02
Chapter 28 Configuring SPAN and RSPAN
Configuring SPAN and RSPAN
RSPAN Configuration Guidelines
Follow these guidelines when configuring RSPAN:
•
All the items in the
“SPAN Configuration Guidelines” section on page 28-11
apply to RSPAN.
•
As RSPAN VLANs have special properties, you should reserve a few VLANs across your network
for use as RSPAN VLANs; do not assign access ports to these VLANs.
•
You can apply an output ACL to RSPAN traffic to selectively filter or monitor specific packets.
Specify these ACLs on the RSPAN VLAN in the RSPAN source switches.
•
For RSPAN configuration, you can distribute the source ports and the destination ports across
multiple switches in your network.
•
RSPAN does not support BPDU packet monitoring or other Layer 2 switch protocols.
•
The RSPAN VLAN is configured only on trunk ports and not on access ports. To avoid unwanted
traffic in RSPAN VLANs, make sure that the VLAN remote-span feature is supported in all the
participating switches.
•
Access ports (including voice VLAN ports) on the RSPAN VLAN are put in the inactive state.
•
RSPAN VLANs are included as sources for port-based RSPAN sessions when source trunk ports
have active RSPAN VLANs. RSPAN VLANs can also be sources in SPAN sessions. However, since
the switch does not monitor spanned traffic, it does not support egress spanning of packets on any
RSPAN VLAN identified as the destination of an RSPAN source session on the switch.
•
You can configure any VLAN as an RSPAN VLAN as long as these conditions are met:
–
The same RSPAN VLAN is used for an RSPAN session in all the switches.
–
All participating switches support RSPAN.
•
We recommend that you configure an RSPAN VLAN before you configure an RSPAN source or a
destination session.
•
If you enable VTP and VTP pruning, RSPAN traffic is pruned in the trunks to prevent the unwanted
flooding of RSPAN traffic across the network for VLAN IDs that are lower than 1005.
•
Catalyst 3750-24PS, 3750-48PS, 3750-24TS, 3750-48TS, 3750G-12S, 3750G-24T, 3750G-24TS
and 3750G-16TD switches have hardware limitations related to RSPAN:
–
An egress SPAN copy of routed unicast traffic might show an incorrect destination MAC
address on both local and remote SPAN sessions. This limitation does not apply to bridged
packets. The workaround for local SPAN is to use the replicate option. For a remote SPAN
session, there is no workaround.
–
Egress SPAN routed packets (both unicast and multicast) show the incorrect source MAC
address. For remote SPAN packets, the source MAC address should be the MAC address of the
egress VLAN, but instead the packet shows the MAC address of the RSPAN VLAN. There is
no workaround.
–
During periods of very high traffic, when two RSPAN source sessions are configured, the
VLAN ID of packets in one RSPAN session might overwrite the VLAN ID of the other RSPAN
session. If this occurs, packets intended for one RSPAN VLAN are incorrectly sent to the other
RSPAN VLAN. This problem does not affect RSPAN destination sessions. The workaround is
to configure only one RSPAN source session.
Содержание 3750G - Catalyst Integrated Wireless LAN Controller
Страница 80: ...1 28 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 1 Overview Where to Go Next ...
Страница 606: ...27 8 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 27 Configuring UDLD Displaying UDLD Status ...
Страница 670: ...31 18 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 31 Configuring SNMP Displaying SNMP Status ...
Страница 1048: ...41 20 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 41 Configuring MSDP Monitoring and Maintaining MSDP ...
Страница 1086: ...43 26 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 43 Troubleshooting Using the crashinfo Files ...
Страница 1104: ...B 4 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Appendix B Supported MIBs Using FTP to Access the MIB Files ...