hot-standby-vc-on (Protocols Layer 2 Circuit)
Syntax
hot-standby-vc-on;
Hierarchy Level
[edit logical-systems logical-system-name protocols l2circuit neighbor address interface interface-name pseudowire-status-tlv], [edit logical-systems logical-system-name routing-instances routing-instance-name protocols vpls mesh-group mesh-group-name neighbor address pseudowire-status-tlv], [edit protocols l2circuit neighbor address interface interface-name pseudowire-status-tlv], [edit routing-instances routing-instance-name protocols vpls mesh-group mesh-group-name neighbor address pseudowire-status-tlv]
Description
On provider edge (PE) aggregation routers, configure
the hot-standby-vc-on statement to indicate that a hot-standby
pseudowire is desired upon arrival of a PW_FWD_STDBY status-tlv. This
flag indicates the standby state. Configure in conjunction with the hot-standby statement on routers that have both active and
standby virtual circuits. Generally, these are access routers.
The goal of the hot-standby statement is to reduce
the amount of traffic being discarded during primary-to-backup transition
periods. This statement enables the possibility of keeping both the
active and standby paths open within the Layer 2 domain. By having
both the active and standby VCs able to send and receive traffic,
traffic loops could potentially occur within the Layer 2 domain. In
consequence, Layer 2 VCs are kept open only in the PE-to-access direction.
In other words, aggregation PE devices can send traffic toward access
devices, but access devices send traffic exclusively through the active
VC.
In this regard, the hot-standby statement is quite
similar to the standby statement. The hot-standby statement
allows for a faster forwarding-path switchover during transition periods,
as compared to what is allowed by the standby statement.
Required Privilege Level
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
Release Information
Statement introduced in Junos OS Release 13.2.
Support for VPLS routing instances added in Junos OS Release 15.1R2.