![]() After the ping is completed, stop the Wireshark capture.From the terminal on H3, ping the default gateway and stop after send 5 echo request packets.# wireshark-gtk & Step 3: Ping H1 from H3. In the terminal window for Node: H3, open Wireshark and start a packet capture for H3-eth0 interface.Repeat until all the cached information has been cleared.Īddress HWtype HWaddress Flags Mask Ifaceġ0.0.0.11 ether 5 a:d 0:1d:01:9f:be C H3-eth0 If there is any existing ARP information in the cache, clear it by enter the following command: arp -d IP-a ddress.In the terminal window for Node: H3, enter arp -n to display the content of the ARP cache.What is the IP address of the default gateway for the host H3?ġ0.0.0.1 Step 2: Clear the ARP cache on H3 and start capturing traffic on H3-eth0. At the prompt on Node: H3, enter netstat -r to display the default gateway information.ĭestination Gateway Genmask Flags MSS Window irtt Ifaceĭefault 10.0.0.1 0.0.0.0 UG 0 0 0 H3-eth0ġ0.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 H3-eth0 Question:.At the prompt on Node: h3, enter ip address to verify the IPv4 address and record the MAC address.At the mininet prompt, start terminal windows on host H3.When prompted, enter cyberops as the password. Open a terminal emulator to start mininet and enter the following command at the prompt.Start and log into your CyberOps Workstation VM using the following credentials:.Step 1: Examine the network configuration of H3. You will then examine the information that is contained in the frame header fields. In Part 2, you will use Wireshark to capture local and remote Ethernet frames. The first 3 octets of the MAC address indicate the OUI.Ħ2:62:6d Part 2: Use Wireshark to Capture and Analyze Ethernet Frames What portion of the MAC address is the OUI? What is the Vendor ID (OUI) of the Source’s NIC? What is the MAC address of the source in the first frame? The ARP broadcast is used to request the MAC address of the host with the IP address contained in the ARP. Why does the PC send out a broadcast ARP prior to sending the first ping request?īefore the PC can send a ping request to a host, it needs to determine the destination MAC address before it can build the frame header for that ping request. This reply contains the MAC address of the NIC of the Default Gateway. T he host with the IP address of 192.168.1.1 (default gateway) will send a unicast reply to the source (PC host). What is significant about the contents of the destination address field?Īll hosts on the LAN will receive this broadcast frame. The value is computed by the sending machine, encompassing frame addresses, type, and data field. The data field is between 46 – 1, 500 bytes.įrame Check Sequence, used by the NIC to identify errors during transmission. Two common frame types are:Ġx 0806 Address resolution protocol (ARP)Ĭontains the encapsulated upper – level protocol. ![]() There are numerous upper – layer protocols supported by Ethernet II. The source address is always unicast.įor Ethernet II frames, this field contains a hexadecimal value that is used to indicate the type of upper – layer protocol in the data field. The destination address may be a broadcast, which contains all ones, or a unicast. The first six hex numbers indicate the manufacturer of the network interface card (NIC), the last six hex numbers are the serial number of the NIC. Each address is 48 bits long, or 6 octets, expressed as 12 hexadecimal digits, 0- 9,A -F. This field contains synchronizing bits, processed by the NIC hardware. Step 1: Review the Ethernet II header field descriptions and lengths. A Wireshark capture will be used to examine the contents in those fields. In Part 1, you will examine the header fields and content in an Ethernet II Frame provided to you. Instructions Part 1: Examine the Header Fields in an Ethernet II Frame In Part 2, you will use Wireshark to capture and analyze Ethernet II frame header fields for local and remote traffic. In the first part of this lab, you will review the fields contained in an Ethernet II frame. When learning about Layer 2 concepts, it is helpful to analyze frame header information. For example, if the upper layer protocols are TCP and IP and the media access is Ethernet, then the Layer 2 frame encapsulation will be Ethernet II. The frame composition is dependent on the media access type. ![]() When upper layer protocols communicate with each other, data flows down the Open Systems Interconnection (OSI) layers and is encapsulated into a Layer 2 frame. Part 2: Use Wireshark to Capture and Analyze Ethernet Frames Background / Scenario Part 1: Examine the Header Fields in an Ethernet II Frame Lab – Using Wireshark to Examine Ethernet Frames (Answers Version)Īnswers Note : Red font color or g ray highlights indicate text that appears in the instructor copy only.
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