FH_InvalidLength - check Fragment Reassembly (Invalid Length)
Host and Router
FH_InvalidLength.seq [-tooloption ...] -pkt FH_InvalidLength.def
-tooloption : v6eval tool option
1. Ping to Target (create Neighbor Cache Entries, if not exist)
2. Override Neighbor Cache Entries
Tester Target
| |
|-------------------------->|
| Echo Request (1st) |
| |
| |
|-------------------------->|
| Echo Request (2nd) |
| |
| |
|<--------------------------|
| ICMP Error |
| |
| |
v v
1. Send Echo Request (1st fragment)
2. Send Echo Request (2nd fragment)
3. Receive ICMP Error
Echo Request (1st fragment) is:
IPv6 Header
Version = 6
Traffic Class = 0
FlowLabel = 0
PayloadLength = 527 (not multiple of 8 octets)
NextHeader = 56 (Fragment Header)
HopLimit = 64
SourceAddress = Tester Link Local Address
DestinationAddress = Target Link Local Address
Fragment Header
NextHeader = 58 (ICMP)
FragmentOffset = 0 (1st fragment)
MFlag = 1 (more fragment)
PASS: ICMP Error Received
IPv6 Header
Version = 6
Traffic Class = 0
FlowLabel = 0
PayloadLength = 575
NextHeader = 58 (ICMP)
HopLimit = 64
SourceAddress = Target Link Local Address
Destination Address = Tester Link Local Address
ICMP Error
Type = 4 (Parameter Problem)
Code = 0 (erroneous header field encounted)
Checksum = (auto)
Pointer = 4 (Pointer to Payload Length in IPv6 Header)
PayloadData = (1st Fragment of Echo Request)
perldoc V6evalTool