Iphrothokholi 47 ngokumelene ne-TCP port 47: amakhanda amabili, imithetho emibili
Inombolo yephrothokholi ne-port kuhlala emakhanda ahlukene, ngakho umthetho owodwa awukwazi ukuthatha indawo komunye. I-PPTP ihlukanisa zombili, futhi ibhokisi le-port alikwazi ukuveza i-GRE.
Amanethiwekhi asemahhotela kanye nezivikelo zomlilo zengqungquthela zivame ukukhombisa ibhokisi lemvume elenziwe ngokwezifiso, futhi othile ubhala u-47 kulo enethemba lokuthi i-PPTP izosebenza. Umthetho uyenziwa, ithuneli isahluleka, futhi umzamo olandelayo usebenzisa enye inombolo. Iphutha lisekhiphakeni ngokwalo: i-IPv4 inensimu yephrothokholi eqamba okulandelayo ngemva kwekhanda le-IP, kuyilapho i-TCP ne-UDP zinensimu ze-port ezikhona kuphela uma ungaphakathi kwelinye lalabo makhanda. Lokhu akuzona izindlela ezimbili zokubhala imvume eyodwa.
Ikhanda le-IPv4 liqamba iphrothokholi elandelayo
Insimu yephrothokholi iyibhayithi eyodwa ekhanda le-IPv4, futhi igcina inombolo echaza umthwalo: u-6 we-TCP, u-17 we-UDP, u-47 we-GRE, u-50 we-ESP. Noma yini ehlunga amakhipha ifunda lelo nani ngaphambi kokubheka ngokujulile, ngoba ikhanda elijulile linengqondo kuphela uma uhlobo selwaziwa. Shintsha i-port kamuva engxoxweni, futhi le nsimu ayinyakazanga.
Ngakho umthetho obhalwe ngokumelene nephrothokholi 47 uchaza ungqimba lwe-IP. Ayikho i-port ebamba iqhaza esinqumweni.
Ama-port akhona ngaphakathi kwe-TCP ne-UDP kuphela
Ama-port yizihlonzi zamabhithi ayishumi nesithupha ngaphakathi kwamakhanda e-TCP ne-UDP, futhi umsebenzi wawo ukuhlukanisa izingxoxo ezabelana ngekheli elilodwa. Ikhanda le-GRE lithwala inani lohlobo lwephrothokholi, ngokuvamile i-EtherType, kanye nokhiye abangakhethekile bokuxhumanisa. Ngakho ibinzana elithi port 47 aliqambi lutho ikhipha le-GRE elingaqondana nalo.
Izixhumanisi zokuvikela umlilo ziyahluka ngokuthi zibonisa okungakanani kwalokhu. Ezinye zamukela inombolo yephrothokholi, ezinye zinikeza uhlu olunamagama, futhi ezimbalwa zamukela i-TCP noma i-UDP kuphela enamaport.
I-PPTP isebenzisa zombili izingqimba ngasikhathi sinye
I-PPTP iyisibonelo esicace kakhulu ngoba ihlukanisa umsebenzi wayo ngamabomu phakathi kwezingqimba ezimbili. Uxhumano lokulawula luyiseshini ye-TCP eya ku-port 1723, futhi indlela yedatha yi-GRE, iphrothokholi 47, kungekho port ehilelekile ndawo. Ukuvikela umlilo okuvumela u-1723 kuphela kuyeka izingxoxo ziqale bese kulahla umthwalo. Ithuneli libonakala lincike ngemva kokuqinisekisa esikhundleni sokwehluleka ukuxhumana, futhi yingakho uphawu luvame ukubikwa njengenkinga yephasiwedi.
| Path | Outer protocol | Port |
|---|---|---|
| Control channel | TCP, protocol 6 | 1723 |
| Data channel | GRE, protocol 47 | None |
Funda imigqa emibili ngokwahlukana uma ubhala umthetho, futhi uhlole ngayinye ngokumelene nesintaksi yomkhiqizi. Umgqa owodwa udinga i-port, omunye udinga inombolo yephrothokholi, futhi akukho okufakiwe okukodwa okuhlanganisa kokubili.
Kungani ikhasi lokudlulisa i-port lingakwazi ukuveza i-GRE
Ifomu lokudlulisa elamukela i-TCP ne-UDP kuphela alikwazi ukuchaza i-GRE, noma ngabe ifomu libizwa ngani. Ukuhumusha amakheli kunezela ubunzima besibili, ngoba i-GRE ayinayo imiphetho futhi umhumushi kufanele alandele isihlonzi socingo esikhundleni salokho. Amanye amarutha asekhaya afika nomsizi ophatha lokhu; amaningi awafiki nawo, futhi akukho okufakiwe okwengeziwe kwemvume ye-TCP okuyodala lowo mkhuba.
Lapho isidingo sangempela kuyithuneli yesimanjemanje, khetha umklamo osebenzisa i-TCP noma i-UDP ngamabomu esikhundleni sokuthemba ukuthi umhumushi uzokuqagela kahle.
Ukuhlanganisa kuthonya ukuthi isihlungi sibona ini
Ukuhlanganisa kushintsha ikhipha elingaphandle, futhi ikhipha elingaphandle yilo umthetho oqondana nalo. I-ESP yemvelo iyiphrothokholi 50, kuyilapho ukudlula kwe-NAT kusonga i-ESP ngaphakathi kwe-UDP 4500 ukuze kusinde ekuhumusheni amakheli. Isihlungi esivumela i-UDP 4500 asikaze sibone iphrothokholi 50, futhi isihlungi esibhalelwe iphrothokholi 50 asikaze siqondane nesimo esisongiwe.
Buza ukuthi yikuphi ukuhlanganisa okwavunyelwana ngakho iklayenti negesiweyidi, bese ubhala umthetho waleso simo sangaphandle kuphela hhayi okunye.
Bhala umthetho ukuze othile akwazi ukuwuhlola
Veza wonke umthetho njengomndeni wamakheli, iphrothokholi yangaphandle, amaport okuthutha uma ekhona, isiqondiso kanye neziphetho zombili. Umhloli angafanisa lowo musho nokubanjwa kwamakhipha bese efinyelela isinqumo. Umyalelo wokuvula u-47 akekho ongawuhlola, futhi yingakho uhlala iminyaka emabhukwini ezinqubo.
Engeza isivivinyo esikufakazelayo lokho: xhuma ngesikhathi ubamba kusixhumanisi sangaphandle, futhi uqinisekise iphrothokholi ne-port yangaphandle ezivela ngempela emkhondweni.