We can easily correlate the MAC address and IP address for any frame with 1 as shown in Figure 4.įigure 4: Correlating the MAC address with the IP address from any frame Host Information from NBNS Trafficĭepending on how frequently a DHCP lease is renewed, you might not have DHCP traffic in your pcap. Based on the hostname, this device is likely an iPad, but we cannot confirm solely on the hostname. In this case, the hostname for 1 is Rogers-iPad and the MAC address is 7c:6d:62:d2:e3:4f. Client Identifier details should reveal the MAC address assigned to 1, and Host Name details should reveal a hostname.įigure 2: Expanding Bootstrap Protocol line from a DHCP requestįigure 3: Finding the MAC address and hostname in a DHCP request Expand the lines for Client Identifier and Host Name as indicated in Figure 3. Go to the frame details section and expand the line for Bootstrap Protocol (Request) as shown in Figure 2. Select one of the frames that shows DHCP Request in the info column. Note: With Wireshark 3.0, you must use the search term dhcp instead of bootp.įigure 1: Filtering on DHCP traffic in Wireshark This filter should reveal the DHCP traffic.

Open the pcap in Wireshark and filter on bootp as shown in Figure 1. This pcap is for an internal IP address at 1. The first pcap for this tutorial, host-and-user-ID-pcap-01.pcap, is available here. NBNS traffic is generated primarily by computers running Microsoft Windows or Apple hosts running MacOS.

DHCP traffic can help identify hosts for almost any type of computer connected to your network.

How do we find such host information using Wireshark? We filter on two types of activity: DHCP or NBNS. If you have access to full packet capture of your network traffic, a pcap retrieved on an internal IP address should reveal an associated MAC address and hostname. In most cases, alerts for suspicious activity are based on IP addresses. Windows user account from Kerberos trafficĪny host generating traffic within your network should have three identifiers: a MAC address, an IP address, and a hostname.Device models and operating systems from HTTP traffic.Host information from NetBIOS Name Service (NBNS) traffic.It assumes you understand network traffic fundamentals and will use these pcaps of IPv4 traffic to cover retrieval of four types of data: This tutorial offers tips on how to gather that pcap data using Wireshark, the widely used network protocol analysis tool. When a host is infected or otherwise compromised, security professionals need to quickly review packet captures (pcaps) of suspicious network traffic to identify affected hosts and users.

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