module 9- Address Resolution

What is the command to show the ARP table on a router?

-show ip arp

What is an ARP cache timer used for?

removes ARP entries that have not been used for a specified period of time.

⦁What happens if they host and destination are on different networks?

the destination MAC address is that of the local default gateway on the router.

What happens on the same network?

the destination MAC address will be that of the destination device

What is the function of Address Resolution Protocol (ARP)?

• Resolving IPv4 addresses to MAC addresses • Maintaining an ARP table of IPv4 to MAC address mappings

Why could ARP broadcasts on a network become an issue?

Excessive ARP broadcasts can cause some reduction in performance.

What is ARP spoofing?

- pretending to be someone you aren't - must be local - can spoof router and create man in the middle attack

What are the two primary addresses assigned to a device on an Ethernet LAN?

-Physical address (MAC address) -Logical address (IP address)

What is the command to show the ARP table on a Windows host?

-arp -a

What happens when a host sends a message and only knows the IP address?

The host needs to know the MAC address of that device, so address resolution comes in.