ISCW10S05L04用访问列表来管理安全.ppt

CiscoDeviceHardening,MitigatingThreatsandAttackswithAccessLists,CiscoACLs,StandardandExtendedACLs,CiscorouterssupporttwobasictypesofIPACLs:StandardIPACL:FiltersIPpacketsbasedonthesourceaddressonlyExtendedIPACL:FiltersIPpacketsbasedonseveralattributes,including:Protocoltype(IP,ICMP,UDP,TCP,orprotocolnumber)SourceanddestinationIPaddressesSourceanddestinationTCPandUDPports,access-list10permit55,access-list101permittcp55anyeq80,IdentifyingACLs,CiscorouterscanidentifyACLsusingtwomethods:ACLnumber:ThenumberoftheACLdetermineswhichprotocolitisfiltering:1to99and1300to1999:StandardIPACLs100to199and2000to2699:ExtendedIPACLsACLname:YouprovidethenameoftheACL:Namescontainalphanumericcharacters.Namescannotcontainspacesorpunctuationandmustbeginwithanalphabeticcharacter.,GuidelinesforDevelopingACLs,BaseACLsonthesecuritypolicy.WriteACLout:WriteoutwhatyouwantthisACLtoaccomplish.Thisisthetimetothinkaboutpotentialproblems.Setupadevelopmentsystem:Thisallowsyoutocopyandpastestatementseasily.ItalsoallowsyoutodevelopalibraryofACLs.StorethefilesasASCIItextfiles.ApplyACLtoarouterandtest:Ifatallpossible,runyourACLsinatestenvironmentbeforeplacingthemintoproduction.,ApplyingACLstoRouterInterfaces,ApplyingACLstoRouterInterfaces,Inbound(in):DataflowstowardrouterinterfaceOutbound(out):Dataflowsawayfromrouterinterface,UsingTrafficFilteringwithACLs,TrafficFiltering,UseACLstofilteringressandegressfromroutersandfirewallappliances.UseACLstodisableandlimitservices,ports,andprotocols.,FilteringNetworkTraffictoMitigateThreats,IPAddressSpoofingMitigation:Inbound,R2(config)#access-list150denyip55anylogR2(config)#access-list150denyip55anylogR2(config)#access-list150denyip55anylogR2(config)#access-list150denyip55anylogR2(config)#access-list150denyip55anylogR2(config)#access-list150denyip55anylogR2(config)#access-list150denyiphost55anylogR2(config)#access-list150permitipany55R2(config)#interfacee0/0R2(config-if)#ipaccess-group150inR2(config-if)#exit,IPAddressSpoofingMitigation:Outbound,“Beagoodcitizenandpreventyournetworkfrombeingspoofed.”,R2(config)#access-list105permitip55anyR2(config)#access-list105denyipanyanylogR2(config)#interfacee0/1R2(config-if)#ipaccess-group105inR2(config-if)#end,DoSTCPSYNAttackMitigation:BlockingExternalAccess,R2(config)#access-list109permittcpany55establishedR2(config)#access-list109denyipanyanylogR2(config)#interfacee0/0R2(config-if)#ipaccess-group109inR2(config-if)#end,DoSTCPSYNAttackMitigation:UsingTCPIntercept,R2(config)#iptcpinterceptlist110R2(config)#access-list110permittcpany55R2(config)#access-list110denyipanyanyR2(config)#interfacee0/0R2(config-if)#ipaccess-group110inR2(config-if)#end,DoSSmurfAttackMitigation,R2(config)#access-list111denyipanyhost55logR2(config)#access-list111permitipany55logR2(config)#access-list112denyipanyhost55logR2(config)#access-list112permitipany55logR2(config)#interfacee0/0R2(config-if)#ipaccess-group111inR2(config-if)#endR2(config)#interfacee0/1R2(config-if)#ipaccess-group112inR2(config-if)#end,FilteringInboundICMPMessages,R2(config)#access-list112denyicmpanyanyechologR2(config)#access-list112denyicmpanyanyredirectlogR2(config)#access-list112denyicmpanyanymask-requestlogR2(config)#access-list112permiticmpany55R2(config)#interfacee0/0R2(config-if)#ipaccess-group112inR2(config-if)#end,FilteringOutboundICMPMessages,R2(config)#access-list114permiticmp55anyechoR2(config)#access-list114permiticmp55anyparameter-problemR2(config)#access-list114permiticmp55anypacket-too-bigR2(config)#access-list114permiticmp55anysource-quenchR2(config)#access-list114denyicmpanyanylogR2(config)#interfacee0/1R2(config-if)#ipaccess-group114inR2(config-if)#end,FilteringUDPTracerouteMessages,R2(config)#access-list120denyudpanyanyrange3340034400logR2(config)#access-list120permitipany55logR2(config)#interfacee0/1R2(config-if)#ipaccess-group120inR2(config-if)#end,MitigatingDistributedDoSwithACLs,BasicsofDistributedDoSAttacks,DistributedDoSattacksexploitspecificports.ACLscancontrolaccessonaport-by-portbasis.,MitigateDistributedDoSUsingMartianFilters,RFC3704isupdatetoRFC2827,DistributedDoSAttackMitigation:TRIN00,R2(config)#access-list190denytcpanyanyeq1524logR2(config)#access-list190denytcpanyanyeq27665logR2(config)#access-list190denyudpanyanyeq31335logR2(config)#access-list190denyudpanyanyeq27444logR2(config)#interfacee0/0R2(config-if)#ipaccess-group190inR2(config-if)#endR2(config)#interfacee0/1R2(config-if)#ipaccess-group190inR2(config-if)#end,DistributedDoSAttackMitigation:Stacheldraht,R2(config)#access-list190denytcpanyanyeq16660logR2(config)#access-list190denytcpanyanyeq65000logR2(config)#interfacee0/0R2(config-if)#ipaccess-group190inR2(config-if)#endR2(config)#interfacee0/1R2(config-if)#ipaccess-group190inR2(config-if)#end,DistributedDoSAttackMitigation:Trinityv3,R2(config)#access-list190denytcpanyanyeq39168logR2(config)#interfacee0/0R2(config-if)#ipaccess-group190inR2(config-if)#endR2(config)#interfacee0/1R2(config-if)#ipaccess-group190inR2(config-if)#end,DistributedDoSAttackMitigation:SubSeven,R2(config)#access-list190denytcpanyanyeq1243logR2(config)#access-list190denytcpanyanyeq2773logR2(config)#access-list190denytcpanyanyrange67116713logR2(config)#access-list190denytcpanyanyeq6776logR2(config)#access-list190denytcpanyanyeq7000logR2(config)#access-list190denytcpanyanyeq7215logR2(config)#access-list190denytcpanyanyeq27374logR2(config)#access-list190denytcpanyanyeq27573logR2(config)#access-list190denytcpanyanyeq54283logR2(config)#interfacee0/0R2(config-if)#ipaccess-group190inR2(config-if)#endR2(config)#interfacee0/1