PLANET EPL-1000 - Manual (Page 50)

4.4.3 L3 Switching
The OLT may be configured as an L3 bridge, enabling the OLT to learn IPv4 destination
addresses. The L3 panel allows the user to configure the OLT for L3 switching. This
operation should generally be performed prior to applying any VLAN provisioning. Bridging
configurations that make use of the CoS field are incompatible with L3 switching. The
primary advantage of L3 switching is security. L3 switching enables the OLT to direct ARP
and RRARP frames based on the learned IP address, making the network less susceptible
to MAC spoofing attacks.
„ DHCP Snooping Enable
This parameter enables the OLT to learn IP frames based on snooping DHCP offer
messages.
„ DHCP Option 82 (Relay Agent Sub-Option…)
If L3 switching is enabled the OLT may be configured as a DHCP relay agent (RFC 3046.)
This will
enable the OLT to insert the Relay Agent Sub-Option into snooped frames.
„ DHCP IPv4 Address Learning
DHCP IPv4 Enables IPv4 address learning via DHCP snooping. Frames shall not be
forwarded until L3 address is learned. ARP frames shall be unicast to appropriate link.
„ ARP Snooping (Snoop ARP Frames…)
ARPsnoop Enables the OLT to classify ARP frames into its processor FIFO. This allows the
OLT to redirect the frames based on learned IPv4 destination address.
- 50 -