ping_siit_frag.seq - Verify IPv6 <-> IPv4 header translation in
accordance with RFC2765 [SIIT]
Router
ping_siit_frag.seq [-tooloption ...] -p ping_siit_frag.def
Before this test starts, run initialize.seq.
This test verifies that NUT translates between IPv6 (fragment hdr)
and IPv4 (DF=0). It also tests ICMPv6 echo <-> ICMPv4 echo
translation.
Network Topology
Link0
--------------------------
| |
TN NUT
| |
--------------------------
Link1
TN -- (Link0) -- NUT NUT -- (Link1) -- TN
--------------------- ------------------------
1.1.1
===================>
ICMPv6 Echo Request
IPv6 Header
src address : TN LINK0 IPv4 embedded IPv6 address
dst address : TN LINK1 IPv4 embedded IPv6 address
Fragment Header
More fragments = 0
ICMPv6 echo request 1.1.2
<>
===================>
ICMPv4 Echo request
IPv4 Header
src address : TN LINK0 IPv4 address
dst address : TN LINK1 IPv4 address
Don't Fragment = 0
More fragments = 0
ICMPv4 echo request
1.2.1
<===================
ICMPv4 Echo Reply
IPv4 Header
src address : TN LINK1 IPv4 address
dst address : TN LINK0 IPv4 address
Don't Fragment = 0
More fragments = 0
ICMPv4 echo reply 1.2.2
<>
<===================
ICMPv6 Echo Reply
IPv6 Header
src address : TN LINK1 IPv4 embedded IPv6 address
dst address : TN LINK0 IPv4 embedded IPv6 address
Fragment Header
More fragments = 0
ICMPv6 echo reply
<< PASS >>
TN (Link1) received ICMPv4 echo request,
with DF=0 in IPv4 header.
TN (Link0) received ICMPv6 echo reply,
with a fragment header after IPv6 header. << FAIL >>
NUT did not translate between ICMPv6 echo and ICMPv4 echo,
or NUT did not translate between IPv6 fragment header
and IPv4 DF option.
B3.1. Translating IPv4 Headers into IPv6 Headers [...] IPv4 packets with DF not set will always result in a fragment
header being added to the packet [...]3.3. Translating ICMPv4 Headers into ICMPv6 Headers Echo and Echo Reply (Type 8 and Type 0)
Adjust the type to 128 and 129, respectively, and adjust the
ICMP checksum both to take the type change into account and
to include the ICMPv6 pseudo-header.4.1. Translating IPv6 Headers into IPv4 Headers If there is no IPv6 Fragment header the IPv4 header fields are set as
follows: If the IPv6 packet contains a Fragment header the header fields are
set as above with the following exceptions: 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.4.2. Translating ICMPv6 Headers into ICMPv4 Headers Echo Request and Echo Reply (Type 128 and 129)
Adjust the type to 0 and 8, respectively, and adjust the ICMP
checksum both to take the type change into account and to
exclude the ICMPv6 pseudo-header.
perldoc V6evalTool