Question

answer all of the questions below. each question is 3 points. list the fields and their sizes in the icmp packet format. what is the total size of the icmp header? (not to exceed 3 lines) what is the last hop and how do we determine it? (not to exceed 3 lines) list the 7-layer osi reference model. which layers in the 7-layer osi model use the ip address and which layers use the mac address?

Answer 1

The ICMP header is 8 bytes without additional data, and the last hop is identified using tools like traceroute. The OSI model consists of 7 layers with IP addresses used at the Network layer and MAC addresses at the Data Link layer.

Step-by-step explanation:

The ICMP packet header consists of the following fields: Type (8 bits), Code (8 bits), Checksum (16 bits), and different fields that vary according to the Type/Code such as Identifier (16 bits), Sequence Number (16 bits), and additional data (variable size). The total size of the ICMP header is 8 bytes without the additional data.

The last hop is the final router that transmits the ICMP packet before it reaches its destination. It is determined using tools like traceroute or tracert, which record the path that packets take through the network by incrementing time-to-live (TTL) values.

The 7-layer OSI reference model includes the following layers: 1. Physical, 2. Data Link, 3. Network, 4. Transport, 5. Session, 6. Presentation, 7. Application. IP addresses are used at the Network layer, while MAC addresses are used at the Data Link layer of the OSI model.