rfc2765_4.1_frag.seq - Verify IPv6 <-> IPv4 header
translation in accordance with RFC2765 [SIIT]
Router
rfc2765_4.1_frag.seq [-tooloption ...]
-p rfc2765_4.1_frag.def
Before this test starts, run initialize.seq.
This test verifies that NUT translates an IPv6 package with Fragment
header to an IPv4 package with DF=0, and copies Offset and MF flag.
Network Topology
Link0
--------------------------
| |
TN NUT
| |
--------------------------
Link1
TN -- (Link0) -- NUT NUT -- (Link1) -- TN
--------------------- ------------------------
1.1.
===================>
ICMPv6 Echo Request
IPv6 Header
src address : TN LINK0 IPv4 embedded IPv6 address
dst address : TN LINK1 IPv4 embedded IPv6 address
NextHeader = 58
PayloadLength = 14
ICMPv6 echo request 1.2.
<>
===================>
ICMPv4 Echo request
IPv4 Header
src address : TN LINK0 IPv4 address
dst address : TN LINK1 IPv4 address
Don't Fragment = 1
More fragments = 0
Offset = 0
ICMPv4 echo request
2.1.[1-2]
===================>
ICMPv6 Echo Request
IPv6 Header
src address : TN LINK0 IPv4 embedded IPv6 address
dst address : TN LINK1 IPv4 embedded IPv6 address
NextHeader = 44
PayloadLength = 22
Fragment Header
More fragments = (0)
or (1)
FragmentOffset = 0
ICMPv6 echo request 2.2.[1-2]
<>
===================>
ICMPv4 Echo request
IPv4 Header
src address : TN LINK0 IPv4 address
dst address : TN LINK1 IPv4 address
(DF,MF,Offset) = (0, 0, 0)
or (0, 1, 0)
ICMPv4 echo request
3.1.[1-2]
===================>
ICMPv6 Echo Request
IPv6 Header
src address : TN LINK0 IPv4 embedded IPv6 address
dst address : TN LINK1 IPv4 embedded IPv6 address
NextHeader = 44
PayloadLength = 22
Fragment Header
More fragments = (0)
or (1)
FragmentOffset = 20
Payload data = ICMPv4 echo request 3.2.[1-2]
<>
===================>
ICMPv4 Echo request
IPv4 Header
src address : TN LINK0 IPv4 address
dst address : TN LINK1 IPv4 address
(DF,MF,Offset) = (0, 0, 20)
or (0, 1, 20)
Payload data = ICMPv4 echo request
<< PASS >>
NUT translates IPv6 packages to IPv4 packages, including
Fragment header when needed. << FAIL >>
NUT fails the translation.
B4.1. Translating IPv6 Headers into IPv4 Headers If the IPv6 packet contains a Fragment header the header fields are
set as above with the following exceptions: Total Length:
Payload length value from IPv6 header, minus 8 for
the Fragment header, plus the size of the IPv4
header. Flags:
The More Fragments flag is copied from the M flag in
the Fragment header. The Don't Fragments flag is set
to zero allowing this packet to be fragmented by IPv4
routers. Fragment Offset:
Copied from the Fragment Offset field in the Fragment
Header.
perldoc V6evalTool