Operating instructions

176 Cisco Systems Intelligent Gigabit Ethernet Switch Module
A quick rundown for verifying your RSPAN session
On CIGESM1, run the command show monitor, and review the output for the desired
configuration:
Session 1
---------
Type : Remote Source Session
Source Ports :
Both : Gi0/1
Reflector Port : Gi0/19
Dest RSPAN VLAN: 500
On 6500-1, run the command show monitor, and review the output for the desired
configuration:
Session 5
---------
Type : Remote Destination Session
Source RSPAN VLAN : 500
Destination Ports : Gi2/2
Attach a sniffer or other network monitor to port g2/2 on 6500-1, start a continuous ping from
BladeServer 1 to its default gateway for vlan 10 (ping 10.1.10.254 -t), and confirm that you
can capture these pings on the sniffer.
Note that for a good understanding of the rules and how to configure SPAN and RSPAN, you
can review the following documents:
http://www.cisco.com/en/US/products/hw/switches/ps628/products_configuration_guide_chapter0
9186a00801a6ba9.html
http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_guide_chapter0
9186a008007f323.html
7.5.4 Topology 3b: Similar to Topology 3a except using a direct cross connect
This topology (Figure 7-19) is similar to topology 3a, except the redundancy is now being
performed through a connection directly between the two Cisco Systems IGESMs. In this
case, because we are now using each Cisco Systems IGESM as a back-up path to the
aggregation switches for the other Cisco Systems IGESM, we must include all of the VLANs
on each Cisco Systems IGESM, and their uplinks, to allow traffic to correctly pass if one of the
primary uplinks between a Cisco Systems IGESM to a 6500 fails.
The advantage of topology 3a is that when the primary root switch fails, the traffic switches
over to the secondary root switch directly. The advantage of topology 3b is that it saves some
cabling effort and requires fewer ports on the upstream switches. From an optimal traffic path
point of view, the topology in 3a is recommended if dedicated RSPAN ports are required.
Based on this recommendation, the example in this section is only offered as a possibility and
is not highly recommended.
Important: It is imperative to understand the rules of using RSPAN prior to implementing it
in your environment. Failure to understand the proper use of RSPAN can lead to
unexpected and undesired results. Review the information in 7.5.3, “Topology 3a: Dual
Cisco Systems IGESMs, two-port aggregation with RSPAN” on page 160 before
attempting to deploy RSPAN.