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short answer: the first packet is not sent out before ARP completes. In order to send a packet, the sender (usually operating system) needs to fill out its IP and Ethernet header. Thus it cannot send a packet before MAC of P3 is known, i.e. ARP completes. long answer: The idea of what happens on the host is following. application (ping) gets an address (...


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Each host maintains an ARP cache, where it stores for a predefined amount of time (quite large) this information. Thus if a communication occurred recently between the two hosts, the address is already in the cache. Additionally some host (depending on their operating system) emit a gratuitous arp when their interface comes UP. I.E. they advertise to the ...


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when I try to ping PC3 from PC1, I expected the first packet to timeout The attempt of using PC3's address as destination triggers the ARP request. ping's ICMP echo request can only be sent after the ARP has succeeded. Before knowing the destination's MAC address, there is nothing to even send the echo request to. How did the packet arrive without knowing ...


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DHCP isn't of any help here, but a managed switch usually is. You cannot really test a cable against the specs without the proper equipment ie. a certifying cable tester. These testers start around 800€, so you might not have one around. Cheaper cable testers test for shorts and continuity only (10-50€), or may also check correct pairings (200-400€). Neither ...


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I understand that a L2 device like WAP is needed to forward packets from one client to another within the same network (based on MAC mostly like in 802.11) Only in Infrastructure Mode. However my question is, if there is no WAP and just a wifi router available(L3 device) to which clients are connected..then.. is it really possible for clients to be able to ...


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Is knowing MAC needed for talking to another device in same wifi network? Short answer: yes. WAPs and wired switches are network bridges, working at the data link layer (L2). Bridges forward frames based on their destination MAC address while at the same time learning node locations by each frame's source MAC address. IP addresses belong to the network ...


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I want to understand why two devices can not talk to each other directly when they are in wireless range of each other? All devices only communicate with the WAP in Infrastructure Mode. That actually increases the range of the Wi-Fi network, and it makes for a more stable network, especially if the Wi-Fi devices are mobile. Is knowing MAC of each other ...


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