Clients with High DNS Delay

The Clients had unusually high DNS delay insight can be accessed from the Global, Site, and Access Points context. This insight provides information on significant delays in response from the DNS Domain Name System. A DNS server functions as a phone book for the intranet and Internet users. It converts human-readable computer host names into IP addresses and IP addresses into host names. It stores several records for a domain name such as an address 'A' record, name server (NS), and mail exchanger (MX) records. The Address 'A' record is the most important record that is stored in a DNS server, because it provides the required IP address for a network peripheral or element. servers. It is categorized under connectivity since there is a high delay in response from the DNS server. The DNS request/responses were significantly delayed insight displays the following information:

• Time Series Graph
• Cards

Time Series Graph

The time series graph displays the number of delays from the DNS server that occurred during the selected time. You can hover your mouse over each bar graph to see the exact number of delays.

Cards

The cards vary based on the context that you access the insight from. Click one of the cards to view further details:

Table 1: Cards Context

Cards	Context
Site	Global
Server	Global, Site, Device
Access Point	Global, Site
Client	Global, Site, Device

Site

Lists the number of sites that experience delays from the DNS server in the network. Click the arrow to view the pictorial graph of the Most Impacted sites. Click the number displayed on the Site card, to view a detailed description of the impacted sites:

• Site—Name of the site impacted by the insight and link to the specific insight at the site context.
• Min (ms)—Packet latency (delay) is measured. The lowest value of delay in the measurement interval is the minimum response delay.
• Avg (ms)—Packet latency (delay) is measured. The average value of delay in the measurement interval is the minimum response delay.
• Max (ms)—Packet latency (delay) is measured. The maximum value of delay in the measurement interval is the maximum response delay.

Server

Lists the number of DNS servers that is impacted by this insight. Click the arrow to view the pictorial graph of the Most Impacted servers. Click the number displayed on the Server card, to view a detailed description of the impacted servers:

• Server IP—IP address of each server.
• Avg (ms)—Packet latency (delay) is measured. The average value of delay in the measurement interval is the minimum response delay.
• Min (ms)—Packet latency (delay) is measured. The lowest value of delay in the measurement interval is the minimum response delay.
• Max (ms)—Packet latency (delay) is measured. The maximum value of delay in the measurement interval is the maximum response delay.

Access Point

Lists the number and details of APs that have the most DNS response delays. Click the arrow to view the pictorial graph of the Most Impacted access points. Click the number displayed on the Access Point card, to view a detailed description of the impacted access points:

• AP Name—Name of the access points and link to the specific insight at the AP context.
• AP MAC—MAC Media Access Control. A MAC address is a unique identifier assigned to network interfaces for communications on a network. address of the AP and link to the specific insight at the AP context.
• AP Serial—Serial number of the AP.
• Avg (ms)—Packet latency (delay) is measured. The average value of delay in the measurement interval is the minimum response delay.
• Min (ms)—Packet latency (delay) is measured. The lowest value of delay in the measurement interval is the minimum response delay.
• Max (ms)—Packet latency (delay) is measured. The maximum value of delay in the measurement interval is the maximum response delay.
• Servers—Server ID where the AP resides.
• Model—Model number of each AP.
• FW Version—Version of the firmware running on each AP.
• Site—Name of the site where the AP resides.

Client

Lists the client name, average delay, and the number DNS response delays that occurred in each client. Click the arrow to view the pictorial graph of the Most Impacted clients. Click the number displayed on the Client card to view a detailed description of the impacted clients:

• Client Name—Name of the impacted client and link to the specific insight at the client context.
• Client MAC—MAC address of the client and link to the specific insight at the client context.
• Avg (ms)—Average DNS response delay in each client.
• Max (ms)—Maximum DNS response delay in each client.
• Min (ms)—Minimum DNS response delay in each client.
• Device Type—Type of OS where the client resides.