'Non-authoritative' indicates that the answer was retrieved from a cache rather than directly from an authoritative DNS server.
If no DNS server is specified, nslookup sends the query to the default local DNS server.
The Domain Name System (DNS) translates hostnames to IP addresses, fulfilling a critical role in the Internet infrastructure.
A DNS client sends a query to its local DNS server and receives a response back, while the hierarchical DNS servers communicate with each other to resolve the client's DNS query.
nslookup is a tool available in most Linux/Unix and Microsoft platforms that allows users to query DNS servers for information.
To run nslookup in Linux/Unix, you just type the nslookup command on the command line.
To run nslookup in Windows, open the Command Prompt and run nslookup on the command line.
nslookup is a command-line tool used to query DNS servers for information about domain names, such as their IP addresses or DNS records.
This command requests the IP address for the host www.mit.edu from the default DNS server.
The -type=NS option specifies that the query should return the names of the authoritative DNS servers for a given domain.
The dns-server option specifies which DNS server to query; if not supplied, the query is sent to the default local DNS server.
The command ipconfig /flushdns clears all entries in the DNS cache and reloads the entries from the hosts file.
You can determine the IP address of your local DNS server by using the ipconfig command.
This command directs the query to the DNS server bitsy.mit.edu instead of the default server, allowing for a direct transaction between the querying host and the specified DNS server.
The destination port for the DNS query message is typically port 53.
The 'Type' of DNS query can vary, such as A, AAAA, or NS, depending on the specific query being made.
To 'annotate' means to highlight specific parts of the packet printout and add explanatory text to clarify findings.
Yes, the response message may also include the IP addresses of the MIT nameservers if available.
ipconfig is a command-line utility used for managing DNS information stored in your host, including viewing and clearing cached DNS records.
Time to Live (TTL) is the duration in seconds that a DNS record is cached before it is considered expired and needs to be refreshed.
Typically, the query message does not contain answers; it is sent to request information from the DNS server.
The number of 'answers' in the DNS response message can vary, and each answer contains specific information related to the query.
ipconfig is a command-line utility in Windows that displays the current TCP/IP network configuration values, including IP address and DNS server addresses.
The command ipconfig /displaydns displays the cached DNS records stored on the host, showing each entry's remaining Time to Live (TTL) in seconds.
The DNS query message is sent to the IP address of the DNS server, which may be the default local DNS server.
A DNS response is the reply from a DNS server containing the requested information, such as the IP address associated with a domain name.
DNS query and response messages are typically sent over UDP.
The 'Type' of a DNS query indicates the kind of information being requested, such as A (address) or MX (mail exchange).
nslookup is a command-line tool used to query the Domain Name System (DNS) to obtain domain name or IP address mapping, or other DNS records.
ifconfig is a command-line utility in Linux/Unix that is similar to ipconfig, used to configure and display network interface parameters.
This filter removes all packets that neither originate nor are destined to your host, allowing for focused packet capture.
DNS queries are requests sent to a DNS server to resolve a domain name into an IP address or retrieve other DNS records.
If the IP address is not that of the default local DNS server, it may correspond to another DNS server specified in the query.
ipconfig is used to empty the DNS cache in your host before capturing DNS packets.
The destination port for the DNS query message is typically port 53.
Packet capture is used to monitor and analyze network traffic, allowing users to see DNS queries and responses in real-time.
The response message provides the nameservers associated with MIT, which can be found in the NS records.
A TCP SYN packet is the initial packet sent in a TCP connection establishment process, indicating a request to start a connection.
The number of 'answers' in the DNS response message can vary based on the query and the DNS records available.
The source port of the DNS response message is typically the same as the destination port of the DNS query, which is usually port 53.
nslookup is a network utility used to query the Domain Name System (DNS) to obtain domain name or IP address mapping information.
Each answer in the DNS response typically contains information such as the IP address associated with the queried domain name.
