Unit 4 Dynamic Host Configuration Protocol (DHCP)
what is DHCP lease?
- duration for which a DHCP server loans an IP address to a DHCP client - default value of three days - you can configure the lease duration
DHCP Scope Guidelines
- if your network has more than one DHCP server > be sure that their DHCP scopes do not overlap - assign DHCP options to the DHCP server if clients need them - assign static IP addresses to non-DHCP clients - assign static IP addresses to all servers on your network - configure DHCP relay agents if one DHCP server must serve hosts on several subnets
requirements for setting up a scope
- name of the scope - description of the scope (optional) - starting (network number) and ending IP addresses (broadcast) of the scope - subnet mask for the scope to be assigned - starting and ending IP addresses to be excluded from the scope > stops DHCP from leasing out the IP address of static IP addresses - lease duration
what is typically the time to live (TTL) for a leased IP address
3 days
what action occurs during the DHCP discover step
the client broadcasts a request for a DHCP server
what is a DHCP lease
the duration for which a DHCP server loans an IP address to DHCP client
DHCP Process (DORA)
- DHCP Discover > client broadcasts a request for a DHCP server - DHCP Offer > DHCP servers on the network offer an address to the client - DHCP request > client broadcasts a request to lease an address from one of the offering DHCP servers - DHCP Ack > server acknowledges the client > assigns it any configured DHCP options > updates its DHCP database
DHCP scope
- a range of IP addresses that a DHCP server can lease out to DHCP clients - leased for a specific Time to Live (TTL) - DHCP servers do not share scope information - set aside static IP addresses for use by printers or servers - each scope must be unique
intro
- designed to reduce configuration time for TCP/IP networks - automatically assigns IP addresses to clients during the log on process - has a pool of IP addresses (known as a scope) that is distributed to clients
what protocol automatically assigns an IP address to clients during the log in process
DHCP
during which step in the DHCP process does the DHCP server assign the IP address or other DHCP option
DHCP acknowledge
what action occurs during the DHCP acknowledge step
DHCP server assigns the IP address or other DHCP option
DHCP servers share their database of leased IP addresses. True/False
False
what is a DHCP scope
a range of IP addresses that a DHCP server can lease out
what is the purpose of DHCP
designed to reduce configuration time for TCP/IP networks by automatically assigning IP addresses to clients during the log in process
during which step in the DHCP process does the client broadcast a request for a DHCP server
discover
what is the four step process for obtaining a DHCP lease for an IP address?
discover, offer, request, ack
what is the next step in the DHCP process after the client has been offered an address
request
when can administrators create a pool of static IP addresses within the DHCP scope
when an IP address will never change such as a printer
