Configuring DHCP

Question 1

Scope properties

Answer 1

• IP address range
  
  • And excluded addresses
• Subnet mask
• Lease durations
• Other scope options
  
  • DNS server, default gateway, WINS server

Question 2

DHCP pools

Answer 2

• Grouping of IP addresses
  
  • Each subnet has its own scope
  • 192.168.1.0/24, 192.168.2.0/24, 192.168.3.0/24, etc.

• A scope is generally a single contiguous pool of IP
addresses
• DHCP exceptions can be made inside of the scope

Question 3

DHCP address allocation

Answer 3

• T1 timer
• Check in with the lending DHCP server to renew the
IP address
• 50% of the lease time (by default)

• T2 timer
• If the original DHCP server is down, try rebinding
with any DHCP server
• 87.5% of the lease time (7/8ths)

Question 4

DHCP address allocation

Answer 4

• Dynamic allocation
• DHCP server has a big pool of addresses to give
out
• Addresses are reclaimed after a lease period

• Automatic allocation
  
  • Similar to dynamic allocation
  • DHCP server keeps a list of past assignments
  • You’ll always get the same IP address

• Static allocation
• Administratively configured table of MAC addresses
• Each MAC address has a matching IP address
• Other names - Static DHCP Assignment, Static
DHCP, Address Reservation, IP Reservation