Alcatel-Lucent 7210 SAS-X - Common Configuration Guidelines; Configuration Guidelines for DHCP Relay and Snooping; Configuring Option 82 Handling

Interface Configuration
7210 SAS-X OS Services Guide Page 939
Common Configuration Guidelines
The topic in this section are:
• Configuration Guidelines for DHCP relay and snooping on page 939
• Configuring Option 82 Handling on page 939
Configuration Guidelines for DHCP relay and snooping
The following configuration guidelines must be followed to configure DHCP relay and snooping.
• On 7210 SAS-M and 7210 SAS-X, DHCP snooping is not supported for SDPs
• 7210 SAS devices does not support the ARP populate based on the DHCP lease, assigned
to the DHCP client
• 7210 SAS devices does not maintain the DHCP lease assigned to the client
• 7210 SAS devices do not perform IP spoofing checks and MAC spoofing checks based on
the DHCP parameters assigned to the client
• MAC learning must be enabled in the VPLS service, for DHCP snooping.
• DHCP snooping is not supported for B-SAPs in B-VPLS services and I-SAPs in I-VPLS
services.
• Ingress ACLs cannot be used to drop DHCP control packet.
• DHCP packets received over a SDP cannot be identified and option-82 inserted by the
node cannot be removed by the node, in the downstream direction. If this behavior is not
needed user should not enable DHCP snooping in the VPLS service, if the DHCP server is
reachable over the SDP (either spoke-sdp or mesh-sdp).
Configuring Option 82 Handling
Option 82, or “Relay Information Option” is a field in DHCP messages used to identify the
subscriber. The Option 82 field can already be filled in when a DHCP message is received at the
router, or it can be empty. If the field is empty, the router shoulMAC learning must be enabled in
the VPLS service, for DHCP snooping.d add identifying information (circuit ID, remote ID or
both). If the field is not empty, the router can decide to replace it.
The following example displays an example of a partial BSA configuration with Option 82 adding
on a VPLS service. Note that snooping must be enabled explicitly on a SAP.
*A:7210SAS>config>service#
----------------------------------------------
vpls 2 customer 1 create