FL_NonZeroToHost - check Flow Label Non-Zero to Host
Host and Router
FL_NonZeroToHost.seq [-tooloption ...] -pkt FL_NonZeroToHost.def
-tooloption : v6eval tool option
None
Tester Target
| |
|-------------------------->|
| Echo Request |
| |
| |
|<--------------------------|
| Neighbor Solicitation |
| |
| |
|-------------------------->|
| Neighbor Advertisement |
| |
| |
|<--------------------------|
| Echo Reply |
| |
| |
v v
1. Send Echo Request 2. Wait Echo Reply or NS 3. If NS received then send NA, and wait Echo Reply again 4. Receive Echo Reply
Echo Request Data is:
IPv6 Header
Version = 6
Traffic Class = 0
FlowLabel = 0x34567 (20 bit)
PayloadLength = 16
NextHeader = 58 (ICMP)
SourceAddress = Tester Link Local Address
DestinationAddress = Target Link Local Address
ICMP Echo Request
Type = 128 (Echo Request)
Code = 0
Checksum = (auto)
Identifier = 0xffff
SequenceNumber = 1
PayloadData = {1,2,3,4,5,6,7,8}
PASS: Echo Reply Received
IPv6 Header
Version = 6
Traffic Class = 0
FlowLabel = 0
PayloadLength = 16
NextHeader = 58 (ICMP)
SourceAddress = Target Link Local Address
Destination Address = Tester Link Local Address
ICMP Echo Reply
Type = 129 (Echo Reply)
Code = 0
Checksum = (auto)
Identifier = 0xffff (same as Echo Request)
SequenceNumber = 1 (same as Echo Request)
PayloadData = {1,2,3,4,5,6,7,8} (same as Echo Request)
WARN: Echo Reply Received
IPv6 Header
Version = 6
Traffic Class = 0
FlowLabel = 0x34567 (20 bit)
PayloadLength = 16
NextHeader = 58 (ICMP)
SourceAddress = Target Link Local Address
Destination Address = Tester Link Local Address
ICMP Echo Reply
Type = 129 (Echo Reply)
Code = 0
Checksum = (auto)
Identifier = 0xffff (same as Echo Request)
SequenceNumber = 1 (same as Echo Request)
PayloadData = {1,2,3,4,5,6,7,8} (same as Echo Request)
RFC2460
3. IPv6 Header Format
Flow Label 20-bit flow label. See section 6.
6. Flow Labels
The 20-bit Flow Label field in the IPv6 header may be used by a source to label sequences of packets for which it requests special handling by the IPv6 routers, such as non-default quality of service or "real-time" service. This aspect of IPv6 is, at the time of writing, still experimental and subject to change as the requirements for flow support in the Internet become clearer. Hosts or routers that do not support the functions of the Flow Label field are required to set the field to zero when originating a packet, pass the field on unchanged when forwarding a packet, and ignore the field when receiving a packet.
perldoc V6evalTool