![]() Observe the source and destination fields.Browse to Domain Name System > Flags, last line is the reply code, the 0 of which means no error. In the Packet Details pane, notice this packet has Ethernet II, Internet Protocol Version 4, User Datagram Protocol and Domain Name System (query).ĭ. ![]() Select the DNS packet contains Standard query and A in the Info column.Ĭ. Note: The provided screenshots are just examples. Enter udp.port = 53 in the filter box and click the arrow (or press enter) to display only DNS packets. Observe the traffic captured in the Wireshark Packet List pane. Click Stop capturing packets to stop the Wireshark capture. The domain name is used in this example.Į. At a command prompt or terminal, type nslookup enter the interactive mode.ĭ. Perform an internet search for the commands to clear the DNS cache for an older OS.Ĭ. NSCD: sudo systemctl restart rviceģ) For the macOS, enter sudo killall -HUP mDNSResponder to clear the DNS cache in the Terminal. Systemd-Resolved: sudo systemctl restart rviceĭNSMasq: sudo systemctl restart rvice The following commands restart the associated service using elevated privileges: (ii) If you are using system-resolved, enter systemd-resolve –flush-caches to flush the cache for Systemd-Resolved before restarting the service. Systemd-Resolved: systemctl status rviceĭNSMasq: systemctl status rvice (i) Identify the utility used in your Linux distribution by checking the status: If your Linux distribution does not use one of the listed utilities, please perform an internet search for the DNS caching utility for your Linux distribution. Select an active interface with traffic for packet capture.ġ) In Windows, enter ipconfig /flushdns in Command Prompt.Ģ) For the majority of Linux distributions, one of the following utilities is used for DNS caching: Systemd -Resolved, DNSMasq, and NSCD. USBPcap is experimental, and it could cause USB problems on your PC. If you are prompted to install USBPcap, do NOT install USBPcap for normal traffic capture. Follow the on-screen instructions to install Wireshark. Download the latest stable version of Wireshark from Choose the software version you need based on your PC’s architecture and operating system.ī. Instructions Part 1: Capture DNS Traffic Step 1: Download and install Wireshark.Ī. If using a packet sniffer such as Wireshark is an issue, the instructor may wish to assign the lab as homework or perform a walk-through demonstration. It is recommended that permission is obtained before running Wireshark for this lab. Instructor Note: Using a packet sniffer such as Wireshark may be considered a breach of the security policy of the school. 1 PC with internet access and Wireshark installed.In this lab, you will install Wireshark and use Wireshark to filter for DNS packets and view the details of both DNS query and response packets. ![]() Because Wireshark allows you to view the packet details, it can be used as a reconnaissance tool for an attacker. Wireshark allows you to filter traffic for network troubleshooting, investigate security issues, and analyze network protocols. Wireshark gives a detailed breakdown of the network protocol stack. Wireshark is an open source packet capture and analysis tool. ![]() Instructor Note: Red font color or gray highlights indicate text that appears in the instructor copy only. 17.1.7 Lab – Exploring DNS Traffic (Instructor Version) ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |