CCIE Routing & Switching v5 Workbook -
CCIE R&S v5 Advanced Technology Labs -
LAN Switching
SPAN
You must load the initial configuration files for the section, LAN
Switching Initial Spanning Tree, which can be found in
. Reference
the Virtual Routers & Physical Switches Diagram to complete this
task.
Task
Configure SW1 so that all traffic transiting VLAN 146 is redirected to a host located
on port Fa0/24.
Configure SW4 so that all interface Fa0/8 traffic is redirected to a host located on
port Fa0/24.
Untagged inbound traffic from the host on port Fa0/24 should be placed into
VLAN 146.
Configuration
SW1:
monitor session 1 source vlan 146
monitor session 1 destination interface FastEthernet0/24
SW4:
monitor session 1 source interface FastEthernet0/8
monitor session 1 destination interface FastEthernet0/24 ingress vlan 146
Verification
The Switchport Analyzer (SPAN) feature is used to redirect traffic from a port or
VLAN onto another port for analysis by devices such as a packet sniffer or Intrusion
Prevention Sensor (IPS). There are three variations of SPAN: Local SPAN (or just
SPAN), Remote SPAN (or RSPAN), and Encapsulated Remote SPAN (or
ERSPAN). ERSPAN is only supported on high-end platforms, such as the Cisco
6500/7600 or Nexus 7000. Instead of having the destination of the SPAN be a local
port (SPAN) or a VLAN (SPAN), ERSPAN can send the traffic to be analyzed over a
Layer 3 network using GRE encapsulation.
With Local SPAN, as shown in this design, traffic coming from or going to a
particular port is redirected to another local port. The source of traffic can also be a
VLAN, as shown on SW1. Normally when the SPAN feature is configured, the
switch drops all traffic coming back in from the SPAN destination port. The
ingress
keyword tells the switch to accept inbound traffic from a SPAN destination port and
assign the traffic to a particular VLAN.
SW1#show monitor session 1
Session 1
---------
Type: Local Session
Source VLANs:Both: 146
Destination Ports
: Fa0/24
Encapsulation
: NativeIngress: Disabled
!
!SW4#show monitor session 1
Session 1
---------
Type: Local Session
Source Ports:Both: Fa0/8
Destination Ports
: Fa0/24
Encapsulation
: NativeIngress: Enabled, default VLAN = 146
Ingress encap : Untagged