When traffic is initiated from desktop which process starts first; the ARP process or ANDing process?

  • What "ANDing process" do you mean? – Zac67 Jul 26 '20 at 15:42
  • When a source host attempts to communicate with a destination host, the source host uses its subnet mask to determine whether the destination host is on the local network or a remote network. This is known as the ANDing process – K Raghu Jul 26 '20 at 15:50
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    The "ANDing process" is correctly called a route lookup. Route lookups always happen first. ARP doesn't happen until an (ethernet) interface is selected, but the route selection process. – Ricky Jul 27 '20 at 2:23
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This is known as the ANDing process

Not really. A host does check that the destination address is on the same network or not, and, yes, it performs a bitwise AND with its mask and the destination address to check that, but I'm not sure where you see such a name for that.

In any case, The decision of whether or not the destination is on the same network as the source must be made first. If the destination is on the same network, then the source host will check its ARP table to see if it already knows about the destination MAC address, and, if not, it will send an ARP request. If the destination is on a different network, the source host does the same ARP process, but using its configured gateway address instead of the destination host address.

As you can see, before it checks ARP, the host must determine if the destination is on the same network or not.

  • Thankyou I am clear so far still traffic reaches to gateway of souce ip if destination is on different network in my next question please. – K Raghu Jul 26 '20 at 16:33

When traffic is initiated from PC , PC will performs ANDing process first to know whether source and destination belong to same networks or different networks . After ANDing process ,ARP process starts .

==> If same networks means packet will forwarded to next connected devices L2 switch and in L2 switch it checks for mac -address table and forwards frame to destination on basis of mac-address table ..

==> If different destination means packet is forwarded to gateway . Again from gateway packet will forward to destination on basis of routing table.

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