修改linux端口范围ip-local-port-range

修改linux端⼝范围ip_local_port_rangetags:ip_local_port_range端⼝范围sysctlLinux中有限定端⼝的使⽤范围，如果我要为我的程序预留某些端⼝，那么我需要控制这个端⼝范围，本⽂主要描述如何去修改端⼝范围。12/proc/sys/net/ipv4/ip_local_port_range的原⽂解释：The/proc/sys/net/ipv4/ip_local_port_rangedefinesthelocalportrangethatisusedbyTCPandUDPtraffictochoosethelocalport.Youwillseeintheparametersofthisfiletwonumbers:ThefirstnumberisthefirstlocalportallowedforTCPandUDPtrafficontheserver,thesecondisthelastlocalportnumber.Forhigh-usagesystemsyoumaychangeitsdefaultparametersto32768-61000-first-last./proc/sys/net/ipv4/ip_local_port_range定义了本地tcp/udp的端⼝范围。可以理解为系统中的程序会选择这个范围内的端⼝来连接到⽬的端⼝（⽬的端⼝当然是⽤户指定的）。12[root@localhost~]#cat/proc/sys/net/ipv4/ip_local_port_range3276861000可以看到，现在定义的范围是32768-61000.如果想修改这个范围，可以使⽤sysctl⼯具，sysctl的配置⽂件位于/etc/sysctl.conf。先看⼀下man中的描述12345678910111213141516171819202122232425262728293031323334[root@kedacommcu]#mansysctlSYSCTL(8)SYSCTL(8)NAMEsysctl-configurekernelparametersatruntimeSYNOPSISsysctl[-n][-e]variable...SYSCTL(8)SYSCTL(8)NAMEsysctl-configurekernelparametersatruntimeSYNOPSISsysctl[-n][-e]variable...sysctl[-n][-e][-q]-wvariable=value...sysctl[-n][-e][-q]-p<filename>sysctl[-n][-e]-asysctl[-n][-e]-ADESCRIPTIONsysctlisusedtomodifykernelparametersatruntime.Theparametersavailablearethoselistedunder/proc/sys/.Procfsisrequiredforsysctl(8)supportinLinux.Youcanusesysctl(8)tobothreadandwritesysctldata.PARAMETERSvariableThenameofakeytoreadfrom.Anexampleiskernel.ostype.The??separatorisalsoacceptedinplaceofa??variable=valueTosetakey,usetheformvariable=value,wherevariableisthekeyandvalueisthevaluetosetitto.Ifthevaluecontainsquotesorcharacterswhichareparsedbytheshell,youmayneedtoenclosethevalueindoublequotes.Thisrequiresthe-wparametertouse.-nUsethisoptiontodisableprintingofthekeynamewhenprintingvalues.-eUsethisoptiontoignoreerrorsaboutunknownkeys.34353637383940414243444546474849505152535455565758596061printthenames.Itmaybeusefulwithshellsthathaveprogrammablecompletion.-NUsethisoptiontoonly-qUsethisoptiontonotdisplaythevaluessettostdout.-wUsethisoptionwhenyouwanttochangeasysctlsetting.-pLoadinsysctlsettingsfromthefilespecifiedor/etc/sysctl.confifnonegiven.Specifying-asfilenamemeansreadingdatafromstandardinput.-aDisplayallvaluescurrentlyavailable.-ASameas-aEXAMPLES/sbin/sysctl-a/sbin/sysctl-nkernel.hostname/sbin/sysctl-wkernel.domainname=""/sbin/sysctl-p/etc/sysctl.confNOTESPleasenotethatmodulesloadedaftersysctlisrunmayoverridethesettings(example:sunrpc.*settingsareoverriddenwhenthesunrpcmoduleisloaded).Thismaycausesomeconfusionduringbootwhenthesettingsinsysctl.confmaybeoverriden.Topreventsuchasituation,sysctlmustberunaftertheparticularmoduleisloaded(e.g.,from/etc/rc.d/rc.localorbyusingtheinstalldirectiveinmodprobe.conf)配置⽂件中也许没有定于范围，那么可以在⽂件中加上，见最后的#test段：123456789101112131415161718192021222324252627282930313233[root@localhost~]#vim/etc/sysctl.conf#KernelsysctlconfigurationfileforRedHatLinux##Forbinaryvalues,0isdisabled,1isenabled.Seesysctl(8)and#sysctl.conf(5)formoredetails.#ControlsIPpacketforwardingnet.ipv4.ip_forward=0#Controlssourcerouteverificationnet.ipv4.conf.default.rp_filter=1#Donotacceptsourceroutingnet.ipv4.conf.default.accept_source_route=0#ControlstheSystemRequestdebuggingfunctionalityofthekernelkernel.sysrq=0#ControlswhethercoredumpswillappendthePIDtothecorefilename#Usefulfordebuggingmulti-threadedapplicationskernel.core_uses_pid=1#ControlstheuseofTCPsyncookiesnet.ipv4.tcp_syncookies=1#Controlsthemaximumsizeofamessage,inbyteskernel.msgmnb=65536#Controlsthedefaultmaxmimumsizeofamesagequeuekernel.msgmax=65536#Controlsthemaximumsharedsegmentsize,inbyteskernel.shmmax=6871947673633343536373839#Controlsthemaximumnumberofsharedmemorysegments,inpageskernel.shmall=4294967296#testnet.ipv4.ip_local_port_range=3276859000修改后，可以使⽤以下命令重新加载123456789101112[root@localhost~]#sysctl-p/etc/sysctl.confnet.ipv4.ip_forward=0net.ipv4.conf.default.rp_filter=1net.ipv4.conf.default.accept_source_route=0kernel.sysrq=0kernel.core_uses_pid=1net.ipv4.tcp_sy