Netscout OneTouch AT 10G, User Manual

Page: 81 / 248

Chapter 4: Network Infrastructure Tests
DNS Server Test
79
The DHCP process has four parts: discover, offer, request, and
acknowledge.
Offer Time is from the start of the DHCP discover
process until an offered IP address is returned by the DHCP server.
The offered address is shown in the Accept field when it has been
accepted by the analyzer.
Total Time is the total amount of time consumed by the DHCP
discover, offer, request, and acknowledge process.
The Subnet Mask is provided to the analyzer by the DHCP server.
Subnet ID - This is the combination of the subnet mask and the
offered IP address (shown in CIDR notation).
Lease Time - This is the amount of time that the IP address is valid.
Expires - This is the accepted time plus the lease duration.
Relay Agent - If a BOOTP DHCP relay agent is present, this shows
its IP address. The relay agent relays DHCP messages between
DHCP clients and DHCP servers on different IP networks.
Offer 2 - If a second address has been offered it is shown here,
and a warning icon is displayed next to the DHCP test icon on
the HOME screen.
MAC Address - The MAC address of the DHCP server.
IPv6 Wired Prefix - The network portion of the IPv6 address,
obtained via router advertisement.
DNS Server Test
Description
The DNS (Domain Name System) server test checks the
performance of DNS servers resolving the specified URL. The
returned IP address as well as DNS server addresses are also
reported.