After a VLAN tag termination sub-interface is configured, you need to configure IP services so that users can access IP services using the VLAN tag termination sub-interface.
Sub-interfaces for VLAN tag termination cannot forward broadcast packets. They automatically discard broadcast packets they receive. To allow VLAN tag termination sub-interfaces to forward broadcast packets, run the arp broadcast enable command on the sub-interfaces to enable the ARP broadcast function.
If the access device supports automatic forwarding of ARP packets, the packets are forwarded even if the ARP broadcast function is disabled on the VLAN tag termination sub-interface.
If the access device does not support automatic forwarding of ARP packets:
The system discards the IP packet if the arp broadcast enable command is not configured on the VLAN tag termination sub-interface. In this case, the route with the VLAN tag termination sub-interface as the outbound interface is considered a black hole route.
If the arp broadcast enable command is configured on the VLAN tag termination sub-interface, the system originates a tagged ARP broadcast packet and forwards it through the VLAN tag termination sub-interface.
When you enable or disable the ARP broadcast function on a VLAN tag termination sub-interface, the routing status of the sub-interface goes Down and then Up. This may result in route flapping on the entire network.
Configure proxy ARP
Configure proxy ARP on the device. For detailed configuration, see the chapter "ARP Configuration" in the HUAWEI NetEngine 8000 F Series Configuration Guide - IP Services.
Configure DHCP
Configure DHCP on the device. For detailed configuration, see the chapter "DHCP Configuration" in the HUAWEI NetEngine 8000 F Series Configuration Guide - IP Services.
On a large-scale network, if clients are connected to a server through other devices instead of being directly connected to the server through Ethernet interfaces, a DHCP server based on a global address pool needs to be configured so that the clients can dynamically obtain IP addresses from the router.
DHCP relay can be configured on the VLAN tag termination sub-interface to insert tag information into Option82. The tag information provides a reference for the DHCP server in IP address allocation.
Configure VRRP
Configure VRRP on the device. For detailed configuration information, see the chapter "VRRP Configuration" in the HUAWEI NetEngine 8000 F Series Configuration Guide - Reliability.
When you configure a VRRP group on VLAN tag termination sub-interfaces, configure the sub-interfaces to add both inner and outer VLAN tags to VRRP packets to ensure that VRRP packets can be transmitted over VLANs. The master and backup devices can then negotiate with each other using VRRP packets. After you enable VRRP on a VLAN tag termination sub-interface, the sub-interface encapsulates or strips the VLAN tags of VRRP packets so that packets can be transmitted in VLANs.
The system view is displayed.
The view of the VLAN tag termination sub-interface is displayed.
Service Type |
VLAN Tag Termination Sub-interface |
Description |
|---|---|---|
Proxy ARP |
Run arp-proxy enable Preeeeeeee. |
- |
DHCP relay |
|
- |
VRRP |
|
When you configure VRRP and static ARP on the dot1q VLAN tag termination sub-interface, the QinQ VLAN tag termination sub-interface, or the VLANIF interface, note the following:
Otherwise, incorrect host routes are generated. This affects packet forwarding between devices. |
ARP broadcast is enabled on the VLAN tag termination sub-interface.
The configuration is committed.