computer 2
Terms
undefined, object
copy deck
- What is DHCP?
- Dynamic Host Configuration Protocol
- What is DHCP's purpose?
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DHCP's purpose is to enable individual computers on an IP network to extract their configurations from a server.
(IP address/gateway) - What is an IP address?
- It is a number that uniquely identifies a computer that is making use of the Internet
- Why shouldn't clients assign IP numbers without the use of a server?
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1. A computer that needs a permanently-assigned IP number might be turned off and lose its number to a machine coming up. This has problems both for finding services and for security.
- What protocol and port does DHCP use?
- DHCP, like BOOTP runs over UDP, utilizing ports 67 and 68
- What is a MAC address?
- A number which uniquely identifes a computer that has an Ethernet interface. (In DHCP's typical use, the server uses a requesting computer's MAC address to uniquely identify it.)
- What is a DHCP lease?
- A DHCP lease is the amount of time that the DHCP server grants to the DHCP client permission to use a particular IP address. A typical server allows its administrator to set the lease time.
- What is a Client ID?
- Whatever is used by the protocol to identify the client computer. (ussually the MAC address, but can be a character string if setup as so)
- Can DHCP support statically defined addresses?
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Yes. At least there is nothing in the protocol to preclude this and one expects it to be a feature of any DHCP server. This is really a server matter and the client should work either way. The RFC refers to this as manual allocation.
- Who Created It?
- The Dynamic Host Configuration Working Group of the Internet Engineering Task Force
- How does DHCP and BOOTP handle multiple subnets?
- A feature of some routers known as "BOOTP forwarding" to forward DHCP or BOOTP requests to a server on another subnet and to forward the replies back to the client.
- In a subnetted environment, how does the DHCP server discover what subnet a request has come from?
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DHCP client messages are sent to off-net servers by DHCP relay agents, which are often a part of an IP router. The DHCP relay agent records the subnet from which the message was received in the DHCP message header for use by the DHCP server.
- Can a DHCP client boot from a BOOTP server?
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Only if the DHCP client were specifically written to make use of the answer from a BOOTP server. It would presumably treat a BOOTP reply as an unending lease on the IP address.
- Can a DHCP server back up another DHCP server?
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You can have two or more servers handing out leases for different addresses. If each has a dynamic pool accessible to the same clients, then even if one server is down, one of those clients can lease an address from the other server.
- Can a BOOTP client boot from a DHCP server?
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Only if the DHCP server is specifically written to also handle BOOTP queries.