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How did the host know which MAC address to send the request to the Web server?
The host knows which MAC address to send a request to because they are on the same subnet, which means they share a local IP address. Only when two hosts belong to different subnets will there be a cause for the local computers to send their data to the default gateway, which would then forward the data to each host.
How ARP learns the MAC address in same subnet?
The ARP request is broadcast all over the network to find out the device having destination IP address. Note – If the destination is present in the same network then ARP will find out destination MAC address but if it is present in different network then ARP will find out default gateway MAC address.
How does it know when to send a packet to the default router?
In a nut-shell, when a router doesn’t know how to route a packet it’ll send the packet to the default gateway/the next “hop”. Basically, when your router can’t find a valid rules (or more formally, it’s route table) it will send the packet to the default gateway, which will typically send it upstream to your ISP.
How does a host determine which packets need to be sent to the default gateway?
Packet goes to that MAC on Ethernet level, despite the fact that it holds a different destination on IP level. So the packet is marked to go to a chosen gateway by setting the “destination MAC” field of the Ethernet frame. The field determines which gateway on that network will get it, if there are multiple gateways.
Can ARP leave the subnet?
ARP only works between devices in the same IP subnet.
How does a host in one subnet know to forward the packet?
If the IP is within the subnet of the local machine, it uses ARP to determine the MAC address of the remote host. If it’s outside, it queries it’s local routing table to find the next hop of that IP, and sends out an ARP query to find the MAC address for that next hop.
How are IP packets routed on a local area network?
Since this is a broadcast, the destination MAC address is FF-FF-FF-FF-FF-FF. Every host on the local subnet will receive the packet. This ARP packet also includes the destination IP address of 192.168.1.2.
What do I need to forward an IP packet?
Create a new Ethernet header for the IP packet to be forwarded. To construct the Ethernet header, you need to know the destination Ethernet MAC address corresponding to the host to which the packet should be forwarded. The next hop host is either: it is an IP address on a router through which the destination is reachable.
Can a subnet tell you the MAC address?
If both subnet addresses are identical the destination is local. If you mean to discover the MAC address for a remote device (for whatever reason) you’ll have to find (or install) a device in the appropriate subnet that can ARP the IP address and tell you the MAC.