What are the ICMP type and code numbers?
Echo Reply (0), Echo Request (8), Redirect (5), Destination Unreachable (3), Traceroute (30), Time Exceeded (11). Many of these ICMP types have a “code” field. Here we list the types again with their assigned code fields.
What does ICMP type mean?
The 4-byte ICMP header contains an 8-bit type field, which defines the ICMP type. The type determines what the ICMP packet is used for. Depending on the type, the 8-bit code field may also be used, which contains additional information. If the type does not have any codes defined, the code field is set to zero.
What does ICMP type 8 mean?
ICMP request
The first byte specifies the type of ICMP message. For example, type 8 is used for an ICMP request and type 0 is used for an ICMP reply. We use type 3 for destination unreachable messages.
What kind of ICMP packet with type 8 is?
Echo Request
Table 3.2 ICMP Message Types
| Type | Description ICMP Message Types |
|---|---|
| 8 | Echo Request (Ping Request, used with Type 0, Ping Reply) |
| 9 | Router Advertisement (Used with Type 9) |
| 10 | Router Solicitation (Used with Type 10) |
| 11 | Time Exceeded |
What is ICMP traceroute?
Traceroute most commonly uses Internet Control Message Protocol (ICMP) echo packets with variable time to live (TTL) values. The response time of each hop is calculated. To guarantee accuracy, each hop is queried multiple times (usually three times) to better measure the response of that particular hop.
Which of the following is not an example of ICMPv4 message?
4. Which of these is not a type of error-reporting message? Explanation: Router error is not a type of error-reporting message in ICMP.
What is traceroute hops?
Traceroute ensures each hop on the way to a destination device drops a packet and sends back an ICMP error message. This means traceroute can measure the duration of time between when the data is sent and when the ICMP message is received back for each hop—giving you the RTT value for each hop.
How do I traceroute an IP address?
How do I use Tracert?
- Open a Command Prompt.
- In the Command Prompt window, type ‘tracert’ followed by the destination, either an IP Address or a Domain Name, and press Enter.
- The command will return output indicating the hops discovered and time (in milliseconds) for each hop.