Dell PowerConnect 7048P User Manual - Page 782
What Is DHCP Snooping?, Dynamic Host Configuration Protocol DHCP Snooping is a security feature
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Page 782 highlights
What Is DHCP Snooping? Dynamic Host Configuration Protocol (DHCP) Snooping is a security feature that monitors DHCP messages between a DHCP client and DHCP server to accomplish the following tasks: • Filter harmful DHCP messages • Build a bindings database with entries that consist of the following information: • MAC address • IP address • VLAN ID • Client port Entries in the bindings database are considered to be authorized network clients. DHCP snooping can be enabled on VLANs, and the trust status (trusted or untrusted) is specified on individual physical ports or LAGS that are members of a VLAN. When a port or LAG is configured as untrusted, it could potentially be used to launch a network attack. DHCP servers must be reached through trusted ports. DHCP snooping enforces the following security rules: • DHCP packets from a DHCP server (DHCPOFFER, DHCPACK, DHCPNAK, DHCPRELEASEQUERY) are dropped if they are received on an untrusted port. • DHCPRELEASE and DHCPDECLINE messages are dropped if the MAC addresses in the snooping database, but the binding's interface is other than the interface where the message was received. • On untrusted interfaces, the switch drops DHCP packets with a source MAC address that does not match the client hardware address. This is a configurable option. 782 Snooping and Inspecting Traffic
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1,210
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1,211
-
1,212
-
1,213
-
1,214
-
1,215
-
1,216
-
1,217
-
1,218
-
1,219
-
1,220
-
1,221
-
1,222
-
1,223
-
1,224
-
1,225
-
1,226
-
1,227
-
1,228
-
1,229
-
1,230
-
1,231
-
1,232
-
1,233
-
1,234