DNS

The Domain Name System (DNS) is a critical component of the Internet, serving as the protocol that translates human-readable domain names (like www.elastiflow.com) into the numerical IP addresses that computers use to communicate with each other. Whenever you type a website address into your browser, DNS servers take that domain name and translate it into the corresponding IP address so your browser can load the website. This process is essential for the functionality of the internet, allowing users to access websites and services using easy-to-remember domain names instead of having to remember complex numerical IP addresses. The DNS protocol operates globally, maintained by a distributed database system across numerous servers worldwide, ensuring the scalability and robustness of internet addressing.

DNS functions as a request/response protocol. When a user attempts to access a website, their computer (the client) sends a DNS query to a DNS server, requesting the IP address associated with the website's domain name. The DNS server then responds with the corresponding IP address, allowing the user's computer to establish a connection to the website's host server. By analyzing DNS request and response messages across a network, IT professionals can detect and troubleshoot disruptions or anomalies in the DNS service. This analysis is crucial because issues with DNS can prevent users from accessing websites and online services, leading to significant disruptions. For instance, a high volume of unresolved DNS requests might indicate a network configuration issue or a malicious attack like a Distributed Denial of Service (DDoS), emphasizing the importance of monitoring DNS traffic for maintaining network integrity and performance.

Low DNS Request/Response Ratio

The Low DNS Request/Response Ratio anomaly detection job is designed to monitor the balance and volume of Domain Name System (DNS) request and response messages within a network. The DNS protocol is pivotal for translating human-readable domain names into IP addresses, which are necessary for routing and accessing internet resources. Under normal circumstances, there is a relatively consistent flow of DNS requests sent from clients to DNS servers, and corresponding responses are received from these servers.

An unusually low volume of DNS messages, or a significant imbalance between requests and responses, can be indicative of several network-related issues:

• DNS Server Issues: A primary concern is the potential malfunction, overload, or misconfiguration of DNS servers. If a server is unable to cope with the volume of incoming requests due to performance limitations or incorrect settings, it may result in fewer responses or delayed responses. This can lead to resolution failures, where users are unable to access websites or online services.

• Network Connectivity Problems: Connectivity issues within the network can disrupt the flow of DNS traffic. If DNS requests are not reaching the server due to network hardware failures, misconfigured routes, or broken links, or if responses are failing to reach the clients, this will result in a lower ratio of responses to requests.

• Security Threats: A low request/response ratio might also indicate security threats such as Denial of Service (DoS) attacks targeting DNS servers or infrastructure. These attacks can flood servers with excessive requests, thereby preventing them from handling legitimate traffic effectively.

• Client Configuration Issues: Problems with client configurations, such as incorrect DNS settings or the use of outdated or unsupported DNS protocols, can lead to a decrease in successful DNS requests, contributing to an imbalance in the request/response ratio.

Attributes

Attribute	Information
Analysis	temporal

Downloads

Schema	Link
CODEX	elastiflow_codex_avail_dns_resp_ratio_low
ECS	elastiflow_ecs_avail_dns_resp_ratio_low

Low DNS Responses

The Low DNS Responses anomaly detection job is focused on identifying instances where there is an unusually low volume of DNS response messages in a network. The DNS (Domain Name System) is a foundational internet service that translates domain names into IP addresses, facilitating the routing of internet traffic. Normally, each DNS query (request) from a client is met with a corresponding response from a DNS server, indicating the IP address associated with the requested domain name or providing an error if the domain cannot be resolved.

A significant reduction in the volume of DNS response messages can suggest various issues:

• DNS Server Overload or Failure: If DNS servers are overwhelmed due to high traffic volumes or are experiencing operational failures (hardware or software issues), they may be unable to respond adequately to incoming queries. This can result in a noticeable drop in response messages, leading to unresolved queries and access issues for users trying to navigate to websites or use internet services.

• Network Connectivity or Configuration Issues: Problems in network connectivity can interfere with the transmission of DNS responses. This could include misconfigured network devices, such as routers or firewalls, that inadvertently block or misroute DNS responses, or physical connectivity problems like broken cables or malfunctioning switches.

• Security Incidents: Anomalously low DNS responses can also indicate security incidents, such as Denial of Service (DoS) attacks targeting DNS infrastructure. These attacks can disrupt the normal operation of DNS servers, preventing them from responding to legitimate queries.

• Client-Side DNS Issues: On the client side, issues such as misconfigured DNS settings or network policies that restrict DNS traffic can result in a failure to receive responses, even though requests are being sent out.

Attributes

Attribute	Information
Analysis	temporal

Downloads

Schema	Link
CODEX	elastiflow_codex_avail_dns_resp_low
ECS	elastiflow_ecs_avail_dns_resp_low