ARP: Address Resolution Protocol Flashcards
What two layers of the OSI model does the ARP protocol translate addresses for?
ARP translates network layer addresses into data link layer address.
Does ARP only translate between MAC and IP addresses?
No, ARP is not protocol specific.
What command allows you to view your ARP cache?
arp -a
What term does the ARP header use to refer to the link-layer address?
Hardware address
What term does the ARP header use to refer to the network address?
Protocol address
What are the first two fields of an ARP header and how many bytes are they?
Hardware type and protocol type. Both are 2 byte fields.
What do the hard size and prot size fields in an ARP header represent and how large are they?
These fields represent the size of the hardware and protocol addresses in bytes. Each field is 1 byte in size.
What are the values used in the OP field in an ARP header and what do they represent?
- ARP request, 2. ARP reply, 3. RARP request, 4 RARP reply
What are the final four fields in an ARP header?
Sender hardware address, sender protocol address, target hardware address, target protocol address.
How many bytes are the hardware and protocol addresses in an ARP header?
Variable. ARP is multi-protocol.
How many bytes are the hardware addresses in an ARP packet on an Ethernet network?
6 bytes
How many bytes are the protocol addresses in an ARP packet on an IPv4 network?
4 bytes
When does a Gratuitous ARP occur?
When a host sends an ARP request for its own IP address.
Why would a host send a Gratuitous ARP request?
To determine if its IP address is currently in use on the network. This is usually done during system bootstrap.
