IPv6 Pain Experiment

Wed Oct 9 09:51:12 UTC 2019

Owen DeLong wrote:

>> Why do you think ICMP any different?
>>
>> Just as usual IP packets, inner IP packets contained in
>> ICMPv4 error packets contain port numbers just after IP headers.
> 
> Show me the port number in a type 8 or type 0 packet.

First 8 bytes of data field can be used as 4 byte source and
destination port numbers.

As I wrote:

 > which is obviously fully operational with existing IPv4 backbone,

we don't need the field interpreted by routers in existing IPv4
backbone. traceroute with ICMP ECHO works with identifier
and sequence number.

After the packet reaches a TCPng/UDPng aware NAT/A+P gateway, we
can expect the field is interpreted as port numbers by the gateway,
A+P routers beyond the gateway and the destination.

> You’re selecting a very limited subset of ICMP that happens to
> contain a portion of a packet that happens to contain a port
> number (or two).

It is merely that you don't understand ICMP at all.

>>>> The point of TCP use IP address for identification is hosts
>>>> can confirm IP address is true by 3 way handshaking.
>>> And UDP?
>>
>> Applications over UDP may or may not confirm by 3 way
>> handshaking or some other mechanism.
>>
>> That's UDP.
> 
> Yes, but the context in which you proposed this as a be-all

See above. The context is TCP.

> end-all solution doesn't allow for the existing things that brea
> when you make the assumptions you've obviously made.

You don't understand UDP, either, at all.

In case of UDP, the assumption is made by someone who
designed application protocol over UDP.

If the designer decided the confirmation is not necessary,
the confirmation is not necessary and protocol is designed
so.

If the designer decided the confirmation is necessary,
the confirmation is necessary and protocol is designed
so.

There is nothing I can or should do for the decision.

>> That's very elementary explanations on ICMP and UDP.
> 
> Yes, thanks for yet another condescending comment proving that
> you completely missed the point of my post. It's always a pleasure.

You should really feel indebted to me because it's not a pleasure
for me to answer questions having no valid points.

						Masataka Ohta