Introduction
This document describes how to configure a Cisco TrustSec (CTS) with Egress reflector.
Prerequisites
Requirements
Cisco recommends that you have basic knowledge of CTS solution.
Components Used
The information in this document is based on these software and hardware versions:
- Catalyst 6500 Switches with Supervisor Engine 2T on IOS® Release 15.0(01)SY
- IXIA Traffic Generator
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Background Information
CTS is an identity-enabled network access architecture that helps customers to enable secure collaboration, strengthen security, and address compliance requirements. It also provides a scalable role based policy enforcement infrastructure. Packets are tagged based on the group membership of the packet source at the ingress of the network. Policies associated with the group are applied as these packets traverse the network.
The Catalyst 6500 series switches with supervisor engine 2T and 6900 series line cards provide complete hardware and software support for implementing CTS. In order to support the CTS functionality, there are dedicated Application Specific Integrated Circuits (ASICs) used on the new 6900 Series line cards. Legacy line cards do not have these dedicated ASICs and therefore, do not support CTS.
CTS reflector uses Catalyst Switch Port Analyzer (SPAN) in order to reflect traffic from a CTS-incapable switching module to the supervisor engine for Security Group Tag (SGT) assignment and insertion.
A CTS egress reflector is implemented on a distribution switch with Layer 3 uplinks, where the CTS-incapable switching module faces an access switch. It supports Centralized Forwarding Cards (CFCs) and Distributed Forwarding Cards (DFCs).
Configure
Network Diagram
Configure SW1
Configure CTS manual on the uplink to SW2 with these commands:
SW1(config)#int t1/4
SW1(config-if)#ip address 10.10.10.1 255.255.255.0
SW1(config-if)#no shutdown
SW1(config-if)#cts manual
SW1(config-if-cts-manual)#propagate sgt
SW1(config-if-cts-manual)#policy static sgt 11 trusted
SW1(config-if-cts-manual)#exit
SW1(config-if)#exit
Configure SW2
Enable egress reflector on the switch with these commands:
SW2(config)#platform cts egress
SW2#write memory
Building configuration...
[OK]
SW2#reload
Note: The switch has to be reloaded in order to enable the egress reflector mode.
Configure CTS Manual on the port connected to SW1 with these commands:
SW2(config)#int t1/4/4
SW2(config-if)#ip address 10.10.10.2 255.255.255.0
SW2(config-if)#no shutdown
SW2(config-if)#cts manual
SW2(config-if-cts-manual)#propagate sgt
SW2(config-if-cts-manual)#policy static sgt 10 trusted
SW2(config-if-cts-manual)#exit
SW2(config-if)#exit
Configure a static SGT on SW2 for the source IP address 10.10.10.10 from IXIA.
SW2(config)#cts role-based sgt-map 10.10.10.10 sgt 11
Verify
Use this section in order to confirm that your configuration works properly.
The current CTS mode can be viewed with this command:
SW2#show platform cts
CTS Egress mode enabled
The CTS link state can be viewed with this command:
show cts interface summary
Verify that the IFC-state is OPEN on both switches. The outputs should look like this:
SW1#show cts interface summary
Global Dot1x feature is Enabled
CTS Layer2 Interfaces
---------------------
Interface Mode IFC-state dot1x-role peer-id IFC-cache Critical-Authentication
-----------------------------------------------------------------------------
Te1/4 MANUAL OPEN unknown unknown invalid Invalid
SW2#show cts interface summary
Global Dot1x feature is Enabled
CTS Layer2 Interfaces
---------------------
Interface Mode IFC-state dot1x-role peer-id IFC-cache Critical-Authentication
-----------------------------------------------------------------------------
Te1/4/4 MANUAL OPEN unknown unknown invalid Invalid
Verify through Netflow Output
Netflow can be configured with these commands:
SW1(config)#flow record rec2
SW1(config-flow-record)#match ipv4 protocol
SW1(config-flow-record)#match ipv4 source address
SW1(config-flow-record)#match ipv4 destination address
SW1(config-flow-record)#match transport source-port
SW1(config-flow-record)#match transport destination-port
SW1(config-flow-record)#match flow direction
SW1(config-flow-record)#match flow cts source group-tag
SW1(config-flow-record)#match flow cts destination group-tag
SW1(config-flow-record)#collect routing forwarding-status
SW1(config-flow-record)#collect counter bytes
SW1(config-flow-record)#collect counter packets
SW1(config-flow-record)#exit
SW1(config)#flow monitor mon2
SW1(config-flow-monitor)#record rec2
SW1(config-flow-monitor)#exit
Apply Netflow on the ingress interface of SW1 switch:
SW1#sh run int t1/4
Building configuration...
Current configuration : 165 bytes
!
interface TenGigabitEthernet1/4
no switchport
ip address 10.10.10.1 255.255.255.0
ip flow monitor mon2 input
cts manual
policy static sgt 11 trusted
end
Verify that the incoming packets are SGT tagged on SW1 Switch.
SW1#show flow monitor mon2 cache format table
Cache type: Normal
Cache size: 4096
Current entries: 0
High Watermark: 0
Flows added: 0
Flows aged: 0
- Active timeout ( 1800 secs) 0
- Inactive timeout ( 15 secs) 0
- Event aged 0
- Watermark aged 0
- Emergency aged 0
There are no cache entries to display.
Cache type: Normal (Platform cache)
Cache size: Unknown
Current entries: 0
There are no cache entries to display.
Module 35:
Cache type: Normal (Platform cache)
Cache size: Unknown
Current entries: 0
There are no cache entries to display.
Module 34:
Cache type: Normal
Cache size: 4096
Current entries: 0
High Watermark: 0
Flows added: 0
Flows aged: 0
- Active timeout ( 1800 secs) 0
- Inactive timeout ( 15 secs) 0
- Event aged 0
- Watermark aged 0
- Emergency aged 0
There are no cache entries to display.
Cache type: Normal (Platform cache)
Cache size: Unknown
Current entries: 0
There are no cache entries to display.
Module 33:
Cache type: Normal
Cache size: 4096
Current entries: 0
High Watermark: 0
Flows added: 0
Flows aged: 0
- Active timeout ( 1800 secs) 0
- Inactive timeout ( 15 secs) 0
- Event aged 0
- Watermark aged 0
- Emergency aged 0
There are no cache entries to display.
Cache type: Normal (Platform cache)
Cache size: Unknown
Current entries: 0
There are no cache entries to display.
Module 20:
Cache type: Normal (Platform cache)
Cache size: Unknown
Current entries: 2
IPV4 SRC ADDR IPV4 DST ADDR TRNS SRC PORT TRNS DST PORT FLOW DIRN FLOW CTS SRC GROUP TAG FLOW CTS DST GROUP TAG IP PROT ip fwd status bytes pkts
=============== =============== ============= ============= ========= ====================== ====================== ======= ============= ========== ==========
10.10.10.10 10.10.20.10 0 0 Input 11 0 255 Unknown 375483970 8162695
10.10.10.2 224.0.0.5 0 0 Input 4 0 89 Unknown 6800 85
Module 19:
Cache type: Normal (Platform cache)
Cache size: Unknown
Current entries: 0
There are no cache entries to display.
Module 18:
Cache type: Normal
Cache size: 4096
Current entries: 0
High Watermark: 0
Flows added: 0
Flows aged: 0
- Active timeout ( 1800 secs) 0
- Inactive timeout ( 15 secs) 0
- Event aged 0
- Watermark aged 0
- Emergency aged 0
There are no cache entries to display.
Cache type: Normal (Platform cache)
Cache size: Unknown
Current entries: 0
Troubleshoot
There is currently no specific troubleshooting information available for this configuration.