dhcp client track

Function

The dhcp client track command enables association between the DHCP client and BFD/IP link on the current interface.

The undo dhcp client track command disables association between the DHCP client and BFD/IP link on the current interface.

By default, association between the DHCP client and BFD/IP link is disabled on the current interface.

Format

dhcp client track { bfd-session local-id | ip-link ip-link-name }

undo dhcp client track

Parameters

Parameter	Description	Value
bfd-session local-id	Specifies the local ID of the tracked BFD session.	The value must be the local ID of an existing BFD session.
ip-link ip-link-name	Specifies the name of the IP link.	The value must be the name of an existing IP link.

Views

Interface view

Default Level

2: Configuration level

Usage Guidelines

When track bfd-session is specified in the command, DHCP is associated with BFD. Association between DHCP and BFD applies to dual upstream links. The main link is the DHCP access link. That is, the FW functions as a DHCP client and obtains an IP address from the DHCP server to access the Internet. The BFD session status dynamically determines the availability of the DHCP access link.

When the BFD session is in Up state, the link is reachable. The DHCP access link is still used as the upstream link.
When the BFD session is in Down state, the link is unreachable. The services are switched to the backup link to ensure service continuity.

When association between DHCP and BFD is configured on the DHCP client, the next-hop address specified for the static BFD session must be nexthop dhcp. That is, the gateway address obtained by the DHCP client is used as the next-hop address to forward BFD packets.

When track ip-link is specified in the command, DHCP is associated with IP link. Similar to association between DHCP and BFD, association between DHCP and IP link also applies to dual upstream links. However, association between DHCP and BFD supports bidirectional detection and fast fault detection, while association between DHCP and IP link provides unidirectional detection.

The parameter dhcp client track can take effect only after the DHCP client on the interface obtains an IP address.

Example

# Configure association between the DHCP client and IP link on GigabitEthernet 0/0/1.

<sysname> system-view
[sysname] dhcp enable
[sysname] interface GigabitEthernet 0/0/1
[sysname-GigabitEthernet0/0/1] dhcp client track ip-link 1