مهوالي مش بيعرف يرد بيقلبها تهريج صح
انت فكر فيها بس عرفت مين الي مش عارف ههههههههه
والكرنال بتاع اي برنامج علي انظمه تشغيل الوندوز الي هيا وندوز سيفن وفيستا واكس بي وماك كيو واللينكس
يبرهن ان كلامك غلط انما في نظم اليونكس واعتقد انك متعرفهاش اساسا هيا الي ممكن اصدقك فيها
يلا اكتبوها يمكن تنفعكم
اقرا الي جاي كده وعلي فكره موقع البرنامج ملوش منتدي انجليزي صيني بس
يعني كل كلامك الي اتقال علي المستخدمين غلط في غلط
ولو بتعرف تقرا صيني قلي لاني غاوزك تترجملي الموقع الجاي ده
الي مش مصدق رابط المنتدي البرنامج موجود[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط]What is ARP?
ARP is the English abbreviation of A
It is a link layer protocol working on the OSI Layer2 to provide a link
between the layer and the hardware interfaces, and meanwhile serve the
upper layer (Network Layer).
The Ethernet exchange equipments on the Layer2 can't identify the IP
address which has 32 bits. They transmit the Ethernet data packets
through 48-bit Ethernet address (we usually call it MAC address), which
means that the transmission of IP data packets on the LAN relies on the
MAC address, not the IP address, to identify the target. Thus, a
corresponding relation must be set up between the IP address and the
MAC address, and hence producing the ARP protocol.
In the Windows Operating System, the active ARP cache of localhost
can be checked through typing command "arp -a" into the command window.
What the ARP cache has saved is the corresponding relation between the
IP address and the MAC address, as shown in the following illustration:[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
In the picture above, the "Internet Address" is IP address, and "Physical Address" is MAC address.
ARP packet can be divided into two types in accordance with different receivers:
Its destination's MAC address is FF-FF-FF-FF-FF-FF. The switch
will transmit the broadcast packet to all the hosts on the LAN after
2. Non-Broadcast. Only specified host can receive the non-broadcast packet.
ARP packet can also be divided into two types according to functions:
1. ARP Request. It's used to access the corresponding MAC address of certain IP address on the LAN.
2. ARP Reply. It's used to inform other host of localhost's IP address and MAC address.
Usually all the Broadcast are ARP Request packets and all the Non-Broadcast are ARP Reply packets.
Suppose there are two host computers on a LAN, the host names, IP addresses and MAC addresses are as follows:
HostName IP MAC
A 192.168.0.1 AA-AA-AA-AA-AA-AA
B 192.168.0.2 BB-BB-BB-BB-BB-BB
When the host A needs to communicate with the host B, it will check
its ARP cache first to see whether it has recorded the host B's MAC
address or not. If the MAC address has been recorded, they can
communicate directly; if not, the host A has to access the host B's MAC
address through ARP protocol. Its specific way is the same as that the
host A asks all the hosts on the LAN: "Hello, who is 192.168.0.2? This
is 192.168.0.1. My MAC address is AA-AA-AA-AA-AA-AA. What is yours?
Come, tell me." The packet sent by the host A belongs to:
Once the host B receives "the ARP Broadcast:Request packet" from the
host A, it will save or update the corresponding relation between the
host A's IP address and MAC address to its ARP cache. Then "an ARP
Non-Broadcast:Reply packet" is sent to the host A, implicating: "Hey,
this is 192.168.0.2, my MAC address is BB-BB-BB -BB-BB-BB". When the
host A receives the reply from the host B, it will save or update the
corresponding relation between the host B's IP address and MAC address
to its ARP cache. Then these two hosts can communicate with each other.
From the process of communication between the hosts on the LAN
mentioned above, we can know that the host will save and update the
local ARP cache table under following two conditions:
1. Having received "Broadcast:Request" packet
2. Having received "Non-Broadcast:reply" packet