Huawei NetEngine80E Configuration Manual - Reliability page 404

HUAWEI NetEngine80E/40E Router
Configuration Guide - Reliability
Issue 02 (2011-09-10)
Router A functions as the master router and Router B functions as the backup router. The
SoftX uses two interface boards, namely, a master interface board and a slave interface
board, to respectively connect both routers. On the master and slave interface boards, the
interfaces that are respectively connected to Router A and Router B are configured with
the same IP address. Normally, the IP address of the interface on the master interface board
is valid.
The SoftX is dual homed to the gateways, that is, Router A and Router B. A VRRP backup
group is configured on VLANIF interfaces. The virtual IP address of the VRRP backup
group and the IP addresses of Router A and Router B are in the same network segment.
The downstream interfaces of Router A and Router B are common Ethernet interfaces.
The VRRP backup group is configured to track the traffic of the downstream interfaces in
reduce mode, and EFM OAM extension for VRRP is enabled.
In addition, the link between Router A and Router B can be configured in either of the
following modes:
– Configuring the link in VLANIF mode - To configure the link in VLANIF mode, you
need to perform the following steps:
– Configure VLANIF interfaces. Therefore, both routers are in one broadcast domain,
that is, a VLAN.
– Add the downstream interface (a Layer 2 interface) of each router into the VLAN.
– Configuring the link in VPLS mode - To configure the link in VPLS mode, you need
to perform the following steps:
– Set up a PW, and configure the downstream interfaces of both routers as the
attachment circuit (AC) interfaces to access the VPLS.
– Configure Layer 2 Virtual Ethernet (L2VE) interfaces between the routers, and bind
the L2VE interfaces and AC interfaces into the same virtual switching instance
(VSI).
– Configure the VRRP backup group on Layer 3 VE (L3VE) interfaces, and bind the
L3VE interfaces and the L2VE interfaces into the same VE group. In this manner,
you can configure Router A and Router B into the same broadcast domain.
All the preceding configurations ensure that the SoftX can detect the faults on the master
link and slave link based on EFM OAM extension and all devices can achieve EFM OAM
extension for VRRP.
Generally, the SoftX decides the link status based on relevant calculations, and then
advertises the link status information to the downstream interfaces of both routers by
sending EFM OAM extension PDUs.
As just mentioned, the VRRP backup group is configured to track the traffic of the
downstream interfaces in reduce mode, and EFM OAM extension for VRRP is enabled.
Therefore, after Router A receives the PDU indicating the link-down state, the VRRP
priority of Router A is reduced, and Router A becomes the backup router. Conversely,
after Router B receives the PDU indicating the link-up state, the VRRP priority of Router
B is increased, and Router B becomes the master router. This can ensure the consistency
between the VRRP master/slave status and the master/slave status of the downstream
interfaces.
In addition, if Router A is notified of a fault that is detected by EFM OAM extension,
Router A considers that the master link is faulty, and thus lowers its VRRP priority. The
SoftX then performs the master/slave failover, and sends the PDU indicating the link-up
state to Router B. The VRRP priority of Router B is thus increased, and Router B becomes
the master router. This can ensure the consistency between the master/slave status of the
SoftX and the master/slave status of both routers.
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8 Ethernet OAM Configuration
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