Accton Technology ES4710BD - Manual (Page 369)

368
E ES4710BD 10 Slots L2/L3/L4 Chassis Switch
Chapter 17 L3 Forward Configuration
ES4710BD supports Layer 3 forwarding which forwards Layer 3 protocol packets (IP packets)
across VLANs. Such forwarding uses IP addresses, when a port receives a IP packet, it will index it
in its own route table and decide the operation according to the index result. If the IP packet is
destined to another subnet reachable from this switch, then the packet will be forwarded from the
appropriate port. ES4710BD can forward IP packets by hardware, the forwarding chip of
ES4710BD has a host route table and default route table. Host route table stores host routes to
connect to the switch directly; default route table stores segment routes (after aggregation algorithm
process).
If the route (either host route or segment route) for forwarding unicast traffic exists in the
forwarding chip, rather than processing by the CPU in router, the forwarding of traffic will be
completely handled by hardware. As a result, forwarding speed can be greatly improved, even to
line speed.
17.1 Layer 3 Interface
17.1.1 Introduction to Layer 3 Interface
Layer 3 interface can be created on ES4710BD. Layer 3 interface is not physical interface but a
virtual interface. Layer 3 interface is built on VLANs. The Layer 3 interface can contain one or
more layer2 interfaces of the same VLAN, or no layer2 interfaces. At least one of the Layer2
interfaces contained in Layer 3 interface should be in a UP state for Layer 3 interface in the UP state,
otherwise, Layer 3 interface will be in the DOWN state. All layer 3 interfaces in the switch use the
same MAC address, this address is selected from the reserved MAC address in creating Layer 3
interface. The Layer 3 interface is the base for layer 3 protocols. The switch can use the IP addresses
set in the layer 3 interface to communicate with the other devices via IP. The switch can forward IP
packets between different Layer 3 interfaces.
17.1.2 Layer 3 interface configuration
17.1.2.1 Layer 3 Interface Configuration Task Sequence
1. Create Layer 3 Interface
Command Explanation
Global Mode
interface vlan
no interface vlan
Creates a VLAN interface (VLAN interface is a
Layer 3 interface); the “no interface vlan