User's Manual Part 2


35JadeOSUserManual
Step4SpecifytheinterfaceofDHCPServer
(JadeOS)(config-dhcp-relay)# server-interface <interface-name>
Step5EnableRelay 
(JadeOS)(config-dhcp-relay)# enable
6.6.4 DHCP Snooping
DHCP Snooping acts as the firewall between untrust host and DHCP server, which
avoid interfere and attack to the legal user. Through DHCP snooping, you can view
thefilteredillegalDHCPmessage.
BecauseDHCPmessagecarriesMACaddressandIPaddressofuserterminal,youcan
obtainandrecordDHCPmessagethroughcontinuouslytrack,whichcanbeused to
indentifyotherillegalDHCPmessage.
ThroughbuildingandmaintainingDHCPsnoopingtable(IP‐MACbinding),systemcan
detectwhetherthefollowedcommunicationislegal,andthenrejecttheunmatched
databetweenIPandMAC.
Toenable DHCPsnooping,usethefollowingcommand:
ip dhcp snooping enable
TodisplayDHCPsnoopingbindingtable,usethefollowingcommand:
(JadeOS) #show ip dhcp snooping binding counter
Datapath Bind Table Statistics
-------------------------------
Current Entries 1001
High Water Mark 1001
Maximum Entries 262144
Total Entries 4001
Allocation Failures 0
(JadeOS) #show ip dhcp snooping binding
DHCP Snooping State is disable
DHCP Snooping verify MAC State is disable
Datapath Binding Table Entries
-------------------------------------------------------------------
Type: D - Dynamic, S - Statically-configured
MacAddress IpAddress Lease(sec) Type Interface
------------- --------------- --------- ------ ------------
00:50:ba:50:77:06 13.0.7.20 300 D Gi 6/10
00:50:ba:50:76:DA 13.0.6.242 300 D Gi 6/10