Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers. If you believe the question would be on-topic on another Stack Exchange site, you can leave a comment to explain where the question may be able to be answered.
Closed 8 years ago.
Improve this question
I've a simple question about IP and MAC.
Lets say we have two LANs, A and B, connected by a Bridge (no Network Layer). We have host 'X', which sends an IP packet to host 'Y'. It will send it through a MAC frame. The Payload of that MAC Frame will be our ip packet.
The question is: since X doesn't know Y's MAC Address, which MAC Destination Address will be used in the Frame's Header?
Thank you for your time.
If the X doesn't know the MAC address of Y it will first send an ARP request to ff:ff:ff:ff:ff:ff (broadcast) requesting the MAC address for the IP address of Y. Y will respond with it's MAC address which X will then use as a destination MAC address to send the frame.
Btw, since the bridge is in between they're actually on the same LAN, not A and B.
Related
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers. If you believe the question would be on-topic on another Stack Exchange site, you can leave a comment to explain where the question may be able to be answered.
Closed 2 years ago.
Improve this question
ARP and RARP are the main Protocol uses in Link Layer. To do the ARP request, a device requires IP and MAC address pair for broadcasting. So my question is ARP doing the mapping the IP to MAC by referring the data
and operates using the LAN.
So RARP is the reverse algorithm of that like mapping logical address to physical address in caches in Computer Systems.
I hope a good answer from the community.
There are dozens of protocols that use the data-link layer the same way ARP does, including IPv4, IPv6, etc. See IEEE 802 Numbers for a list of protocols that use the data-link layer.
For protocols in the data-link layer, there are/were many. For example, token ring, ARCNET, FDDI, frame relay, HDLC, ATM, PPP, etc. Ethernet used to be the king, but Wi-Fi has dethroned it since there are more devices shipping with Wi-Fi interfaces than devices with ethernet interfaces.
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
Closed 7 years ago.
This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers. If you believe the question would be on-topic on another Stack Exchange site, you can leave a comment to explain where the question may be able to be answered.
This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers. If you believe the question would be on-topic on another Stack Exchange site, you can leave a comment to explain where the question may be able to be answered.
Improve this question
I understand the mechanism of ARP but I am wondering why do we use it even if we have the recipient's IP address? Isn't it enough to rely on the recipient's IP address to send packets instead of taking extra steps of finding its matching MAC address?
Thank you.
An IP address is a layer-3 address. Layer-3 packets get encapsulated into layer-2 frames, and layer-2 also has addressing (MAC addresses) which needs to be supplied. ARP (Address Resolution Protocol) resolves the layer-3 IP address to a layer-2 MAC address so that the layer-3 packet can be encapsulated into a layer-2 frame which is then sent out the layer-1 interface.
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers. If you believe the question would be on-topic on another Stack Exchange site, you can leave a comment to explain where the question may be able to be answered.
Closed 8 years ago.
Improve this question
I understand that the MAC address is flashed on the NIC. It is supposed to be unique as is is used by ARP/RARP protocol to map IP to MAC and vice versa. The MAC address needs to be unique otherwise the data delivery will fail. I am wondering the NIC card manufactures are many. How do they ensure that the MAC address is unqiue? If it is not unique then the transmission will fail right? Do they speak to each other that I am using this MAC address, don't use this one? I guess this is not the case.
The first 6 bytes of the MAC address are a prefix that is assigned to each manufacturer by the IEEE. Manufacturer must only use prefixes that are assigned to them, and then they're responsible for ensuring that the remainder of the MAC address is unique within their products.
IEEE Registration Authority
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers. If you believe the question would be on-topic on another Stack Exchange site, you can leave a comment to explain where the question may be able to be answered.
Closed 9 years ago.
Improve this question
I understand that a router uses NAT to translate the public IP we get from the ISP to say 300 local IPs. Does a switch perform the same function? If not, how's it different?
No, a switch cannot perform NAT and translate public(s) IP addresses into private addresses.
A switch is a network device that filters and forwards packets between LAN segments. Switches operate at the data link layer (layer 2). So, they are not aware of IP addresses which are network layer (layer 3). A switch keeps a record of the MAC addresses of all the devices connected to it. With this information, a switch can identify which system is sitting on which port. So when a frame is received, it knows exactly which port to send it to, without significantly increasing network response times.
Routers are network devices used to interconnect two different networks (with different IP addressing schemes).
Closed. This question is off-topic. It is not currently accepting answers.
Want to improve this question? Update the question so it's on-topic for Stack Overflow.
Closed 10 years ago.
Improve this question
MAC address are used for uniquely identifying my computer.
IP address are used for routing the packets to the network, as it has got a hierarchial structure, but it doesn't uniquely identifies a computer. So, after IPv6, each computer will have a unique IP address, so will there be any need of MAC address then?
Please do correct me, if I had understood something wrong.
No. MAC addresses operate at layer 2 ("data link layer"). The Internet Protocol (both IPv4 and IPv6) operates at layer 3 ("network layer").
These two layers are complimentary, and do not "replace" each other. For more information, read up on the TCP/IP suite.
IPv6 stateless address autoconfiguration (SLAAC) uses the MAC address to generate the address, but that does not mean they "replace" each other. It's simply a characteristic of the layer 2 interface being inherited by the layer 3 addressing. Other than that, completely complimentary.