What is DNS query logging?
DNS servers often provide some form of query logging, also referred to as analytical logging. These events detail all requests that are handled by the server. Resolution queries. Events may also be available for recursive lookups performed in order to resolve client queries.
What is DNS query response?
DNS is a query/response protocol. The client queries an information (for example the IP address corresponding to www.google.com) in a single UDP request. DNS uses UDP port 53 to connect to the server. TCP can also be used for response data size exceeding 512 bytes or for specific tasks such as zone transfers.
How do I record DNS queries?
To capture DNS traffic:
- Start a Wireshark capture.
- Open a command prompt.
- Type ipconfig /flushdns and press Enter to clear the DNS cache.
- Type ipconfig /displaydns and press Enter to display the DNS cache.
- Observe the results.
- Type nslookup en.wikiversity.org and press Enter.
- Observe the results.
How do I enable DNS query logging?
Open the run dialogue box by hitting Windows+R keys.
- Now type eventvwr. msc in the dialogue box and hit Enter.
- At this step, navigate to Applications and Service Logs >> Microsoft >> Windows >> DNS Client Events >> Operational.
- You will see Operational option, right click on it and click Enable Log.
How does query logging work in a DNS server?
In the case of query logging, every outbound query sent by the DNS server translates to (eventually) another write-operation to the disk. This load is even heavier when response logging is enabled, since the responses could be very large in size (see examples in Is DNS TCP or UDP).
How is DNS query / response logging with dnstap?
DNS query/response logging with dnstap DNS servers optionally log queries on demand by formatting a message and storing that in a file, sending it through syslog, etc. This is an I/O-intensive operation which can dramatically slow down busy servers, and the biggest issue is we get the query but not the associated response.
Can a DNS server be affected by analytical logs?
DNS analytical logs are not enabled by default, and typically will only affect DNS server performance at very high DNS query rates. For example, a DNS server running on modern hardware that is receiving 100,000 queries per second (QPS) can experience a performance degradation of 5% when analytic logs are enabled.
How is a DNS response based on a query?
A DNS response is based on a query generated for a domain. In the response message, NIOS captures the TTL value of a resource record, the resource record type, and resource data. They log only the answer section and do not include the authority and additional sections.