9 - IPv4 Header Flashcards
A router will drop a packet with a TTL of […]
0
A value of […] in the IP header ‘Version’ field indicates IP version 4.
4 (binary 0100)
A value of […] in the IP header ‘Version’ field indicates IP version 6.
6 (binary 0110)
IPv4 header ‘Flags’ field:
Bit […] = DF bit
1
IPv4 header ‘Flags’ field:
Bit […] = MF bit
2
IPv4 header ‘Flags’ field:
Bit […] = Reserved, always set to 0
0
IPv4 header ‘Flags’ field:
What does ‘DF bit’ stand for?
Don’t Fragment bit
IPv4 header ‘Flags’ field:
What does ‘MF bit’ stand for?
More Fragments bit
IPv4 header ‘Protocol’ field:
Value of 1 = […]
ICMP
IPv4 header ‘Protocol’ field:
Value of 17 = […]
UDP
IPv4 header ‘Protocol’ field:
Value of 6 = […]
TCP
IPv4 header ‘Protocol’ field:
Value of 89 = […]
OSPF
IPv4 header ‘Protocol’ field:
Value of […] = ICMP
1
IPv4 header ‘Protocol’ field:
Value of […] = OSPF
89
IPv4 header ‘Protocol’ field:
Value of […] = TCP
6
IPv4 header ‘Protocol’ field:
Value of […] = UDP
17
IPv4 header: All fragments of the same packet will have the same value in the […] field.
Identification
IPv4 header: the ‘Checksum’ field is […] bits in length.
16
IPv4 header: the ‘Destination IP Address’ field is […] bits in length.
32
IPv4 header: The ‘DSCP’ field is […] bits in length.
6
IPv4 header: The ‘ECN’ field is […] bits in length.
2
IPv4 header: The ‘Flags’ field is […] bits in length.
3
IPv4 header: The ‘Fragment Offset’ field is […] bits in length.
13
IPv4 header: The ‘Identification’ field is […] bits in length.
16
IPv4 header: The ‘IHL’ field is […] bits in length.
4
IPv4 header: The ‘Protocol’ field is […] bits in length.
8
IPv4 header: the ‘Source IP Address’ field is […] bits in length.
32
IPv4 header: The ‘Total Length’ field is […] bits in length.
16
IPv4 header: the ‘TTL’ field is […] bits in length.
8
IPv4 Header: The IHL field specifies the length of the header in […] increments.
4-byte (32 bit)
IPv4 header: What does ‘DSCP’ stand for?
Differentiated Services Code Point
IPv4 header: What does ‘ECN’ stand for?
Explicit Congestion Notification
IPv4 header: What does ‘IHL’ stand for?
Internet Header Length
IPv4 header: What does ‘TTL’ stand for?
Time to Live
IPv4 header: What is the maximum length of the ‘Options’ field?
320 bits / 40 bytes
IPv4 header: What is the maximum value of the ‘Total Length’ field?
65,535
IPv4 header: What is the maximum value of the IHL field?
15
IPv4 header: What is the minimum length of the ‘Options’ field?
0 bits
IPv4 header: What is the minimum value of the ‘Total Length’ field?
20 (=IPv4 header with no encapsulated data)
IPv4 header: What is the minimum value of the IHL field?
5
IPv4 header: Which field indicates the protocol of the encapsulated L4PDU?
Protocol
IPv4 header: Which field indicates the total length of the packet?
Total Length
IPv4 header: Which field is used to check for errors in the header?
Header Checksum
IPv4 header: Which field is used to identify which packet a fragment belongs to?
Identification
IPv4 header: Which field is used to indicate the position of a fragment within an original, unfragmented IP packet?
Fragment Offset
IPv4 header: Which field is used to prevent infinite routing loops?
TTL
IPv4 header: Which field is used to prioritize delay-sensitive network traffic?
DSCP
IPv4 header: Which field provides end-to-end notification of network congestion?
ECN
IPv4 packets are fragmented if they are larger than the […]
MTU (Maximum Transmission Unit)
The IPv4 header ‘Version’ field is […] bits in length.
4
The MTU is usually […] bytes.
1500
The recommended default TTL of an IPv4 packet is […]
64
Unfragmented IPv4 packets will always have the MF bit set to […]
0
What does ‘MTU’ stand for?
Maximum Transmission Unit
What is the maximum length of the IPv4 header?
60 bytes
What is the minimum length of the IPv4 header?
20 bytes