Hello,
I have several questions about handling exceptional situations
in IPv6 packets:
1. How to process packets that have incorrect version number?
Should we discard it or send an ICMPv6 error message?
Ethernet header has an identifier of the included ip-level protocol
packet. Suppose that it identifies the IPv6 packet but the Version
fields of the IPv6 header is not 6. What to do in this case?
Send an error, discard the packet or something else?
2. How to process packets that have incorrect payload length field?
Should we discard it or send an ICMPv6 error message?
IP receives from LAN an array of octets as well as it's length.
If payload length field contains correct value then that length is
equal to the payload length plus 40 (the length of the header).
What to do if the payload length does not match the length of
the octets array received from the LAN level? Should we send
an ICMP error message or silently discard the message?
3. What to do when the total size of options does not match the size
of the header (Hop-by-hop and Destination options headers)?
Each TLV options contains it's data size. What implementations are
supposed to do if the total length of options (calculated from their
Option Data length fields) does not match the length of the header?
4. Jumbo Payload options errors.
What to do if Jumbo Payload option length is not equal to 4?
What to do if there are several Jumbo Payload options in
hop-by-options header?
5. What to do with malformed fragments sequences?
There several possible exceptional situations not covered by
RFC 2460 Section 4.5 such as:
5.1 Fragments overlap.
5.2 Suppose we have received a fragment with M flag set to 0
("rightmost" fragment). Then an exception is a fragment with M flag
set to 1 offset greater than the offset of the "rightmost" fragment.
How implementations are supposed to handle these cases?
Grigory Klyuchnikov, System Engineer,
Institute for System Programming
Russian Academy of Sciences
--------------------------------------------------------------------
IETF IPng Working Group Mailing List
IPng Home Page: http://playground.sun.com/ipng
FTP archive: ftp://playground.sun.com/pub/ipng
Direct all administrative requests to [EMAIL PROTECTED]
--------------------------------------------------------------------
