Huawei S3700-52P-PWR-SI 02354132 User Manual
Product codes
02354132
l
The DHCP server appends the Option 82 field to a Response message. The S3700 analyzes
the Option 82 field, determines a forwarding interface, removes the Option 82 field, and
then forwards the message to a user.
the Option 82 field, determines a forwarding interface, removes the Option 82 field, and
then forwards the message to a user.
Option 82 can be implemented in two modes on the S3700, Option 82 insert and Option 82
rebuild.
rebuild.
The Option 82 field contains the user circuit IDs. The user circuit IDs include user device name,
outer VLAN ID, inner VLAN ID and port number etc. This can effectively prevent attackers
from modifying the DHCP messages.
outer VLAN ID, inner VLAN ID and port number etc. This can effectively prevent attackers
from modifying the DHCP messages.
DHCP Relay
The DHCP client and the DHCP server send broadcast packets during the allocation of IP
addresses. Therefore, DHCP can be applied only when the DHCP client and DHCP server are
in the same subnet. It is a waste of resource to deploy a DHCP server in each network segment.
addresses. Therefore, DHCP can be applied only when the DHCP client and DHCP server are
in the same subnet. It is a waste of resource to deploy a DHCP server in each network segment.
The DHCP relay is introduced to solve this problem. Through DHCP relay, a DHCP client in a
subnet can communicate with the DHCP server in another subnet and finally obtains an IP
address. In this manner, the DHCP clients on different network segments can use the same DHCP
server. This reduces costs and achieves centralized management.
subnet can communicate with the DHCP server in another subnet and finally obtains an IP
address. In this manner, the DHCP clients on different network segments can use the same DHCP
server. This reduces costs and achieves centralized management.
4.9 Network-Level HA
4.9.1 MSTP Protective Switchover
The S3700 supports MSTP to eliminate broadcast storms on a network and provide redundant
links for data transmission.
links for data transmission.
The S3700 provides the root protection function. To retain the role of the root device, you need
to set the role of a designated interface to remain unchanged when the interface receives a BPDU
with higher priority. This prevents incorrect change of the network topology.
to set the role of a designated interface to remain unchanged when the interface receives a BPDU
with higher priority. This prevents incorrect change of the network topology.
The S3700 provides the loop protection function. If the root interface cannot receive any BPDU
from the upstream device, the root interface enters the blocking state and stops forwarding
packets. At the same time, no new root interface is elected. This prevents loops on the network.
from the upstream device, the root interface enters the blocking state and stops forwarding
packets. At the same time, no new root interface is elected. This prevents loops on the network.
4.9.2 RRPP Rapid Protective Switchover
An RRPP ring is applied to the protected dual-homed networks. The RRPP ring can be deployed
between CEs and UPEs, or between UPEs and NPEs.
between CEs and UPEs, or between UPEs and NPEs.
An RRPP ring is composed of a master node and multiple transit nodes that are connected to
each other. The master node periodically sends out protocol packets from the primary interface
to monitor the link status. If the link fails, the master node can enable the secondary interface to
realize self-healing.
each other. The master node periodically sends out protocol packets from the primary interface
to monitor the link status. If the link fails, the master node can enable the secondary interface to
realize self-healing.
If a single-point failure occurs on the ring, the RRPP can enable the backup link as soon as
possible and the link among nodes can recover quickly.
possible and the link among nodes can recover quickly.
4.9.3 Smart Link Dual-Homing Protection
The S3700 is dual-homed to an upstream device through the Smart Link technology. The
downstream links of the S3700 form a Monitor Link group. The layer-by-layer connection of
downstream links of the S3700 form a Monitor Link group. The layer-by-layer connection of
S3700HI Ethernet Switches
Product Description
Product Description
4 Service Features
Issue 05 (2012-10-20)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
30