rfc2765_3.3_icmpv4error.seq - Verify IPv6 <-> IPv4 header
translation in accordance with RFC2765 [SIIT]
Router
rfc2765_3.3_icmpv4error.seq [-tooloption ...]
-p rfc2765_3.3_icmpv4error.def
Before this test starts, run initialize.seq.
This test verifies that NUT can translates ICMPv4 error messages
in accordance to RFC2765.
Network Topology
Link0
--------------------------
| |
TN NUT
| |
--------------------------
Link1
TN -- (Link0) -- NUT NUT -- (Link1) -- TN
--------------------- ------------------------
ICMPv6 (Type 1, Code 0) <= ICMPv4 (Type 3, Code 0) ICMPv6 (Type 1, Code 0) <= ICMPv4 (Type 3, Code 1) ICMPv6 (Type 4, Code 1) <= ICMPv4 (Type 3, Code 2) ICMPv6 (Type 1, Code 4) <= ICMPv4 (Type 3, Code 3) ICMPv6 (Type 2, Code 0, MTU 1028) <= ICMPv4 (Type 3, Code 4, MTU 1000) ICMPv6 (Type 2, Code 0, MTU 1006) <= ICMPv4 (Type 3, Code 4, MTU 0) ICMPv6 (Type 1, Code 0) <= ICMPv4 (Type 3, Code 5) ICMPv6 (Type 1, Code 0) <= ICMPv4 (Type 3, Code 6) ICMPv6 (Type 1, Code 0) <= ICMPv4 (Type 3, Code 7) ICMPv6 (Type 1, Code 0) <= ICMPv4 (Type 3, Code 8) ICMPv6 (Type 1, Code 1) <= ICMPv4 (Type 3, Code 9) ICMPv6 (Type 1, Code 1) <= ICMPv4 (Type 3, Code 10) ICMPv6 (Type 1, Code 0) <= ICMPv4 (Type 3, Code 11) ICMPv6 (Type 1, Code 0) <= ICMPv4 (Type 3, Code 12) Silently drop <= ICMPv4 (Type 5, Code 0) Silently drop <= ICMPv4 (Type 4, Code 0) ICMPv6 (Type 3, Code 1) <= ICMPv4 (Type 11, Code 1) ICMPv6 (Type 4, Code 0, Pointer 0) <= ICMPv4 (Type 12, Code 0, Pointer 0) ICMPv6 (Type 4, Code 0, Pointer 4) <= ICMPv4 (Type 12, Code 0, Pointer 2) ICMPv6 (Type 4, Code 0, Pointer 7) <= ICMPv4 (Type 12, Code 0, Pointer 8) ICMPv6 (Type 4, Code 0, Pointer 6) <= ICMPv4 (Type 12, Code 0, Pointer 9) ICMPv6 (Type 4, Code 0, Pointer 8) <= ICMPv4 (Type 12, Code 0, Pointer 12) ICMPv6 (Type 4, Code 0, Pointer 24) <= ICMPv4 (Type 12, Code 0, Pointer 16) ICMPv6 (Type 4, Code 0, Pointer -1) <= ICMPv4 (Type 12, Code 0, Pointer 1)
<< PASS >>
NUT translates ICMPv4 error messages in accordance with
RFC2765, including translating the inner IP-header.
<< FAIL >>
NUT fails to translate ICMPv4 errors correctly, or doesn't
drop untranslatable ICMPv4 error types.
RFC2765
3.3. Translating ICMPv4 Headers into ICMPv6 Headers
All ICMP messages that are to be translated require that the ICMP checksum field be updated as part of the translation since ICMPv6, unlike ICMPv4, has a pseudo-header checksum just like UDP and TCP.
In addition all ICMP packets need to have the Type value translated and for ICMP error messages the included IP header also needs translation.
The actions needed to translate various ICMPv4 messages are:
ICMPv4 error messages:
Destination Unreachable (Type 3)
For all that are not explicitly listed below set the Type to
1.
Translate the code field as follows:
Code 0, 1 (net, host unreachable):
Set Code to 0 (no route to destination).
Code 2 (protocol unreachable):
Translate to an ICMPv6 Parameter Problem (Type 4,
Code 1) and make the Pointer point to the IPv6 Next
Header field.
Code 3 (port unreachable):
Set Code to 4 (port unreachable).
Code 4 (fragmentation needed and DF set):
Translate to an ICMPv6 Packet Too Big message (Type
2) with code 0. The MTU field needs to be adjusted
for the difference between the IPv4 and IPv6 header
sizes. Note that if the IPv4 router did not set
the MTU field i.e. the router does not implement
[PMTUv4], then the translator must use the plateau
values specified in [PMTUv4] to determine a likely
path MTU and include that path MTU in the ICMPv6
packet. (Use the greatest plateau value that is
less than the returned Total Length field.)
Code 5 (source route failed):
Set Code to 0 (no route to destination). Note that
this error is unlikely since source routes are not
translated.
Code 6,7:
Set Code to 0 (no route to destination).
Code 8:
Set Code to 0 (no route to destination).
Code 9, 10 (communication with destination host
administratively prohibited):
Set Code to 1 (communication with destination
administratively prohibited)
Code 11, 12:
Set Code to 0 (no route to destination).
Redirect (Type 5)
Single hop message. Silently drop.
Source Quench (Type 4)
Obsoleted in ICMPv6. Silently drop.
Time Exceeded (Type 11)
Set the Type field to 3. The Code field is unchanged.
Parameter Problem (Type 12)
Set the Type field to 4. The Pointer needs to be updated to
point to the corresponding field in the translated include
IP header.
http://www.cs.washington.edu/research/networking/napt/reports/usenix98/
A.3 Translating ICMPv4 to ICMPv6
Parameter Problem (Type 12): set the Type field to 4 and translate
the Pointer values as follows:
0-to-0, 2-to-4, 8-to-7, 9-to-6, 12-to-8, 16-to-24, and for all other
ICMPv4 Pointer values set the ICMPv6 Pointer value to -1.
perldoc V6evalTool