Clients with Significant Number of DNS Failures

The Clients had significant number of DNS Failures insight can be accessed from the Global, Site, Access Points, and Clients context. This insight provides information on excessive request failures 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 number of request failures. This Clients had significant number of DNS Failures insight displays the following information:

Insight Summary

The insight summary provides the following details:

  • Reason—Displays the possible causes for which the failure occurred.
  • Recommendation—Displays the possible recommendation against each failure to resolve the same.
  • Failures—Displays the exact number and percentage of failures that occurred against each failure reason.

Time Series Graph

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

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 request failures 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.
  • Total Failures(%)—Total number of failure packets out of transferred packets at the site multiplied by 100.
  • Query Attempts—Number of query attempts sent to the DNS server in a site.
  • Query Success(%)—Percentage of successful DNS queries in a site.
  • Query Format Error—Error in the DNS query format sent to the DNS server in a site.
  • Request Failed to Complete—DNS request failed to complete, and the server responds with an error code.
  • Domain Name Does Not Exist—Domain name sent to the DNS server does not exist and the server responds with an error code.
  • Function Not Implemented—Function is not implemented on the DNS server and the server responds with an error code.
  • Server Refused to Answer Query—Server refused to answer the query and responds with an error code.

Server

Lists the number of servers that have the most number of DNS request rejections. 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.
  • Total Failures(%)—Total number of failure packets out of transferred packets at the site multiplied by 100
  • Query Attempts—Number of query attempts sent to the DNS server
  • Query Success(%)—Percentage of successful DNS queries.
  • Query Format Error—Error in the DNS query format sent to the DNS server in a site.
  • Request Failed to Complete—DNS request failed to complete, and the server responds with an error code.
  • Domain Name Does Not Exist—Domain name sent to the DNS server does not exist and the server responds with an error code.
  • Function Not Implemented—Function is not implemented on the DNS server and the server responds with an error code.
  • Server Refused to Answer Query—Server refused to answer the query and responds with an error code.

Access Point

Lists the number and details of access points that have the most number of DNS request rejections. Click the arrow to view a pictorial graph of the Most Impacted access points. Click the Access Point drop-down list to view the following:

Success Rate—Graphical representation of the total failures and total successful requests that occurred at the server.

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 MACMAC 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.
  • Total Failures(%)—Total number of failure packets out of transferred packets at the site multiplied by 100.
  • Query Attempts—Number of query attempts sent to the DNS server in each AP.
  • Query Success(%)—Percentage of successful DNS queries in each AP.
  • Query Format Error—Error in the DNS query format sent to the DNS server in each AP.
  • Request Failed to Complete—DNS request failed to complete, and the server responds with an error code.
  • Domain Name Does Not Exist—Domain name sent to the DNS server does not exist and the server responds with an error code.
  • Function Not Implemented—Function is not implemented on the DNS server and the server responds with an error code.
  • Server Refused to Answer Query—Server refused to answer the query and responds with an error code.
  • Site—Name of the site where the AP resides.

Client

Lists the client name and number of DNS request rejections 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.
  • Total Failures—Total number of DNS request rejections in each client.
  • Query Attempts—Number of DNS query attempts in each client.
  • Query Success—Number and percentage of successful query attempts in each client.
  • Query Format Error—Number of errors due to query format.
  • Request Failed to Complete—Number of incomplete DNS requests in each client.
  • Domain Name does Not Exist—Number failures due to absence of domain name.
  • Function Not Implemented—Number of failures due to function not implemented.
  • Server Refused to Answer Query—Number of failures due to server rejections.
  • Device Type—Type of OS where the client resides.
  • Top Hostnames—Hostnames that each client was trying to access.