Document Number: OSUP1043
Product: Observer 8.x or greater
Date: 7-24-2003
Title: Configuring Cisco 6000 switches using a SPAN port to a Network Instruments Full-Duplex Gigabit Product

Keywords: Cisco, 6000, 6500, CatOS, IOS, SPAN, Gigabit

When using a Network Instruments Full-Duplex Gigabit product (i.e. The Gigabit Probe Kit, Rack-mount Gigabit Probe or the Gigabit Observer Suite System/GOSS) to capture directly from a SPAN or monitoring port one should use a straight through cable from a Gigabit port on the switch to either port A or B on the gigabit card. Do not use the Y-cable or TAP (the TAP and Y-cable should only be used inline).

To use the Observer product with the Cisco 6xxx switch, you will need to disable auto negotiation. Note: With auto negotiation enabled, you may get a link when first booting up the probe but if the cable is unplugged or configuration change to the monitoring port is applied, you will lose connectivity to the switch. To turn auto negotiation off on the switch, follow the directions based on the OS you are using on your switch:

For switches configured with Cisco CatOS:

To disable port negotiation:
Console> enable
Console>(enable) set port negotiation mod_num/port_num disable

To verify port negotiation:
Console.(enable) show port negotiation [mod_num/port_num]

To enable port negotiation (should you remove the gigabit Observer product from the switch):
Console>(enable) set port negotiation mod_num/port_num enable

For switched configured with Cisco IOS:

To disable port negotiation:
Console> enable
Console# configure terminal
Console(config)# interface gigabitethernet mod_mun/port_num
Console(config-if)# speed nonegotiate

To verify port negotiation:
Console# show interfaces gigabitethernet mod_mun/port_num

To enable port negotiation To enable port negotiation (should you remove the gigabit Observer product from the switch):
Console(config)# interface gigabitethernet mod_mun/port_num
Console(config-if)# no speed nonegotiate

Disabling Auto Negotiation is recommended on all models/brands of switches when using a SPAN/MIRROR/MONITOR port to a Network Instruments Full-Duplex Gigabit product.