Connecting Interfaces; Management-Only Interface - Cisco 3020 - Catalyst Blade Switch Configuration Manual

Chapter 8 Configuring Interface Characteristics

Connecting Interfaces

Devices within a single VLAN can communicate directly through any switch. Ports in different VLANs
cannot exchange data without going through a routing device. In the configuration shown in
when Blade Server A in VLAN 20 sends data to Blade Server B in VLAN 30, the data must go from
Blade Server A to the switch, to the router, back to the switch, and then to Blade Server B.
Figure 8-1
Server A

Management-Only Interface

The Fast Ethernet 0 (fa0) interface is an internal connection to the HP Onboard Administrator and is only
used for switch management traffic, not for data traffic. It is connected to the Onboard Administrator
through the blade server backplane connector. Management information that is sent to or received from
this interface is not sent to the other Ethernet interfaces on the switch. This interface cannot send or
receive data traffic from the servers that are connected to Gigabit interfaces 0/1 to 0/16. The speed and
duplex settings for this interface are fixed at 100 Mpbs and full duplex.
The fa0 interface is a routed interface. You can use the IP addresses that are assigned to this interface to
manage the switch through the HP Onboard Administrator module. By default, the fa0 interface is
assigned an IP address through a DHCP server. You can also statically configure the IP address. You can
see the IP address that is assigned to the fa0 interface from the Onboard Administrator GUI, through
which you can manage the switch through the HP Onboard Administrator module.
We recommend that you set up your network so that you can communicate with the assigned fa0 IP
address from the same external network in which the HP Onboard Administrator is located. For more
information on the IP routing and IP forwarding capabilities of the HP Onboard Administrator module,
see the HP BladeSystem documentation at http://www.hp.com/go/bladesystem/documentation.
If you do not want to manage the switch through the HP Onboard Administrator module, you can disable
the fa0 interface by using the shutdown interface configuration command.
The fa0 interface does not route its received IP packets to the IP Address that is assigned to other VLAN
interfaces on the switch. IP packets that are received by the VLAN interfaces are not routed to the fa0
interface. The fa0 interface is a routed interface, but the switch does not route IP data packets.
OL-8915-01
Connecting VLANs with Layer 2 Switches
Blade
VLAN 20
Cisco router
Blade Switch
Blade
Server B
VLAN 30
Cisco Catalyst Blade Switch 3020 for HP Software Configuration Guide
Understanding Interface Types
Figure 8-1,
8-5