HP OneView - Manual (Page 152)

19.2.5.2.2 Sample active/active configuration
ToR Switch
Physical server 1
NIC TEAM
Port 1 Port 2
IO Bay 1
Network vNet 101A
-Internal VLAN 3
-External VLAN 101
Uplink Set U1
X1 X2
d1
SL1
SL2
IO Bay 2
Network vNet 101B
-Internal VLAN 5
-External VLAN 101
Uplink Set U2
d1
SL1
SL2
X1 X2
VLAN 101
19.2.6 About loop and pause flood protection
Loop protection
The loop protection feature enables detection of loops on downlink ports, which can be Flex-10
logical ports or physical ports. The feature applies when Device Control Channel (DCC) protocol
is running on the Flex-10 port. If DCC is not available, the feature applies to the physical downlink
port.
Network loop protection uses two methods to detect loops:
1. It periodically injects a special probe frame into the HP Virtual Connect domain and monitors
downlink ports for the looped back probe frame. If this special probe frame is detected on
downlink ports, the port is considered to cause the loop condition.
2. It monitors and intercepts common loop detection frames used in other switches. In network
environments where the upstream switches send loop detection frames, the HP Virtual Connect
interconnects must ensure that any downlink loops do not cause these frames to be sent back
to the uplink ports. Even though the probe frames ensure loops are detected, there is a small
time window depending on the probe frame transmission interval in which the loop detection
frames from the external switch might loop through down link ports and reach uplink ports.
By intercepting the external loop detection frames on downlinks, the possibility of triggering
loop protection on the upstream switch is eliminated. When network loop protection is enabled,
HP Virtual Connect interconnects intercept loop detection frames from various switch vendors,
such as Cisco and ProCurve.
When the network loop protection feature is enabled, any probe frame or other supported
loop detection frame received on a downlink port is considered to be causing the network
loop, and the port is disabled immediately until an administrative action is taken. The
administrative action involves resolving the loop condition and clearing the loop protection
error condition. The loop detected status on a port can be cleared by un-assigning all
networks from the profile connect corresponding to the port in the loop detected state.
152 Managing interconnects, logical interconnects, and logical interconnect groups