Question

DHCP is a very promiscuous service, and this can cause unplanned service interruptions if not configured properly. Explain

Answer 1

Answer:-

Dynamic Host Configuration Protocol (DHCP) is a client/server protocol that automatically provides an Internet Protocol (IP) host with its IP address and other related configuration information such as the subnet mask and default gateway. RFCs 2131 and 2132 define DHCP as an Internet Engineering Task Force (IETF) standard based on Bootstrap Protocol (BOOTP), a protocol with which DHCP shares many implementation details. DHCP allows hosts to obtain necessary TCP/IP configuration information from a DHCP server.

this can cause unplanned service interruptions if not configured properly. Explain

Server Not Giving out Addresses

There are a couple of reasons that a server (In this case the Cisco device) will not give out addresses. The most obvious of these is that the server is not configured. On a Cisco DHCP device, this can be verified by viewing the current DHCP pool configuration using the show ip dhcp pool command

Clients Receiving Addresses Already Statically Assigned to Servers or Reserved Devices

A common mistake that happens when configuring a Cisco device as a DHCP server is the failure to reserve addresses that are already in use (including the device itself). By default, when configuring a DHCP pool the whole range of addresses are eligible for lease.

Clients Unable to Reach External Networks (off subnet)

Another common mistake happens when a DHCP server has been configured but clients are unable to reach networks outside the local subnet. When setting up a configuration for client devices that will need to reach clients external to the local subnets (almost all modern clients), a default gateway must be set up inside the DHCP configuration.