Netgear XCM8806 Chassis User Manual - Page 452
Configuring the DHCP Relay, Agent Option Option 82 at Layer 3, defaults to
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NETGEAR 8800 User Manual If the configuration of either VLAN Info or Port Info causes the total string length of - to exceed 32 bytes, then it is truncated to 32 bytes. The string is not NULL terminated, since the total circuit ID length is being specified. For a DHCP client packet ingressing on a VLAN with the VLAN ID equal to 200 and the ingress port at 3:5, the following are true: • When neither VLAN Info or Port Info is specified, circuit ID value is = 200-3005 • When VLAN Info is configured to SomeInfo and Port Info is not specified, the circuit ID value is SomeInfo-3005 • When VLAN Info is not specified and Port Info is configured to User1, the circuit ID value is 200-User1 • When VLAN Info is configured to SomeInfo and Port Info to User1, the circuit ID value is SomeInfo-User1 VLAN Info is configurable per VLAN. When not explicitly configured for a VLAN, VLAN Info defaults to the ASCII string representation of the ingress VLAN ID. To configure the circuit ID on a VLAN, use the following command: configure ip-security dhcp-snooping information circuit-id vlan-information To unconfigure the circuit ID on a VLAN, use the following command: unconfigure ip-security dhcp-snooping information circuit-id vlan-information Port Info is configurable. When not explicitly configured for a port, port info defaults to the ASCII representation of the ingress port's SNMP ifIndex. To configure the port information portion of the circuit-ID, use the following command: configure ip-security dhcp-snooping information circuit-id port-information port To unconfigure the port information portion of the circuit-ID, use the following command: unconfigure ip-security dhcp-snooping information circuit-id port-information ports Note: When this feature is enabled, all DHCP traffic must be forwarded in slowpath only, which means that this feature functions only in the context of IP Security and only on interfaces where DHCP snooping is enabled in enforcement (violation-action of 'drop') mode, in other words with DHCP snooping not configured with a violation-action of 'none' (which is pure monitoring mode). For information about configuring option 82 at Layer 3, see Configuring the DHCP Relay Agent Option (Option 82) at Layer 3 on page 627. 452 | Chapter 17. Security
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