Huawei S3700-52P-PWR-SI 02354132 User Manual
Product codes
02354132
When the designated port enabled with root protection receives a BPDU of higher priority, the
port does not change to a non-designated port. Instead, it turns to the Listening state and stops
forwarding packets. If the port does not receive protocol BPDUs of higher priority for a long
time, it restores the Forwarding state. This prevents network flapping.
port does not change to a non-designated port. Instead, it turns to the Listening state and stops
forwarding packets. If the port does not receive protocol BPDUs of higher priority for a long
time, it restores the Forwarding state. This prevents network flapping.
Loop Protection
After loop protection is enabled on the S3700, it sets the root port to the Blocking state if the
root port does not receive protocol BPDUs from the upstream device. If the port receives protocol
BPDUs again, it becomes the root port and changes to the Forwarding state. If no protocol BPDU
is received, the port remains in the Blocking state and does not forward packets. In this way,
loops are prevented on the network.
root port does not receive protocol BPDUs from the upstream device. If the port receives protocol
BPDUs again, it becomes the root port and changes to the Forwarding state. If no protocol BPDU
is received, the port remains in the Blocking state and does not forward packets. In this way,
loops are prevented on the network.
3.2.4 Partitioned STP and BPDU Tunnel
Partitioned STP
To improve the reliability of links on the enterprise network, the S3700 can be dual-homed to
the upstream Ethernet. In addition, MSTP needs to run on the whole enterprise network to
prevent loops. The traditional MSTP networks are not divided. In this case, the convergence
speed of an MSTP network is low because the network is large. As a result, the forwarding
capability of the network is degraded.
the upstream Ethernet. In addition, MSTP needs to run on the whole enterprise network to
prevent loops. The traditional MSTP networks are not divided. In this case, the convergence
speed of an MSTP network is low because the network is large. As a result, the forwarding
capability of the network is degraded.
By using the partitioned STP technology, the S3700 logically allocates a VLAN for each
partitioned STP network. The tagged BPDUs can be forwarded only within the VLAN that the
tag belongs to. Partitioned STP allows BPDUs to be transmitted within a certain range. This
prevents loops and speeds up convergence.
partitioned STP network. The tagged BPDUs can be forwarded only within the VLAN that the
tag belongs to. Partitioned STP allows BPDUs to be transmitted within a certain range. This
prevents loops and speeds up convergence.
BPDU Tunnel
On a partitioned STP network, the S3700 considers the tagged BPDUs as common Layer 2
frames. That is, the S3700 forwards the BPDUs within the VLAN to which the tag belongs rather
than sending them to the MSTP module. After the BPDU tunnel is configured, the devices on
the MAN do not participate in the topology calculation of the partitioned STP network. Thus,
the convergence speed of the network is improved.
frames. That is, the S3700 forwards the BPDUs within the VLAN to which the tag belongs rather
than sending them to the MSTP module. After the BPDU tunnel is configured, the devices on
the MAN do not participate in the topology calculation of the partitioned STP network. Thus,
the convergence speed of the network is improved.
To implement the BPDU tunnel function, the access device at the edge of the MAN must be
configured with MSTP Snooping. If the forwarding path is changed because of the topology
change on the partitioned STP network, the device can detect the topology change, and then
notify other devices on the network of the topology change. In this way, the packets are forwarded
according to the new topology.
configured with MSTP Snooping. If the forwarding path is changed because of the topology
change on the partitioned STP network, the device can detect the topology change, and then
notify other devices on the network of the topology change. In this way, the packets are forwarded
according to the new topology.
3.3 RRPP
The Rapid Ring Protection Protocol (RRPP) is a link layer protocol applied to the Ethernet ring.
It can prevent the broadcast storm caused by the loops in the Ethernet ring. The topology
convergence speed on the network running RRPP is much faster than that on the network running
other protocols such as STP. This is because the RRPP packets are forwarded through hardware.
It can prevent the broadcast storm caused by the loops in the Ethernet ring. The topology
convergence speed on the network running RRPP is much faster than that on the network running
other protocols such as STP. This is because the RRPP packets are forwarded through hardware.
In addition, the RRPP ring supports link bundle, which is widely used on the high-bandwidth
ring networks.
ring networks.
S3700HI Ethernet Switches
Product Description
Product Description
3 Link Features
Issue 05 (2012-10-20)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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