S7. What is an MTU, what are typical values, and how is it different from MSS?

Question 1

What is MTU?

Answer 1

MTU stands for Maximum Transmission Unit and is the maximum size of a data packet or frame that can be sent in a single network transmission without requiring fragmentation

Question 2

What happens if a packet exceeds the MTU?

Answer 2

It gets fragmented

Question 3

How is MTU measured?

Answer 3

In bytes

Question 4

Why is MTU important?

Answer 4

MTU is critical in networking as it directly affects the efficiency and speed of data transmission.

Question 5

What is the MTU value based on?

Answer 5

The network type

Question 6

What is the standard MTU value?

Answer 6

It depends on the network type. The standard MTU for Ethernet networks is 1500 bytes. This means that the largest IP packet that can be sent over an Ethernet link without fragmentation is 1500 bytes. Other network types may have different MTU values. WLAN’s for example typically have an MTU of 2304 bytes.

Question 7

What is the standard MTU for Ethernet networks?

Answer 7

1500 bytes

Question 8

What is the standard MTU for WLANs?

Answer 8

2304 bytes

Question 9

What is MSS?

Answer 9

MSS stands for Maximum Segment Size. It refers to the largest amount of data that can be received in a single TCP segment, excluding TCP and IP headers.

Question 10

How is MSS calculated?

Answer 10

By subtracting the combined size of the IP and TCP headers from the MTU.

Question 11

What is a typical value for an MSS?

Answer 11

With an MTU of 1500 bytes on an Ethernet network, and assuming the TCP and IP headers are 20 bytes each, the MSS would be 1460 bytes.

Question 12

What is the difference between MTU and MSS?

Answer 12

The difference between MTU and MSS lies in their scope and application. MTU is a general network parameter applicable to any type of data packet, determining the maximum packet size that can be transmitted in one piece. MSS is specific to the TCP protocol and specifies the maximum amount of payload data that TCP can handle without requiring fragmentation at the network layer.

Question 13

What happens if a segment exceeds the MSS?

Answer 13

It gets dropped

Question 14

Why is proper configuration of MTU and MSS values important?

Answer 14

For optimizing network performance and avoiding issues with packet fragmentation and retransmission.