Subject: (ngtrans) Issues about Teredo draft 8

From: [email-masked]
Date: Mon, 24 Mar 2003 15:15:21 +0800

Dear Mr. Huitema:
    I am sorry to bore you since I have some trouble to get through the Teredo specification. :-)
    1. In section 5.3 Teredo server specification:
        5.3.1   Processing of Teredo IPv6 packets
        Upon reception of a packet on the Teredo port, the Teredo server will first check that the UDP payload contains a valid IPv6 packet;  if this is not the case, the packet will be silently discarded. 
       Before processing the packet, the Teredo server MUST check the validity of the encapsulated IPv6 source address, the IPv4 source address and the UDP source port:
       1)      If the UDP content is not a well formed IPv6 packet, the packet MUST be silently discarded. 
       2)      If the UDP packet is not a bubble or an ICMPv6 message, it should be discarded.
       .......
       7) In all other cases, the packet MUST be silently discarded.

       The Teredo server will then check the IPv6 destination address of
the encapsulated IPv6 packet.
        ......
       If the destination address is not a Teredo IPv6 address, the packet
should be relayed to the IPv6 Internet using regular IPv6 routing.
       But in my opinion, If the destination address of a Teredo packet is not a Terdo IPv6 address (Eg. global IPv6 addr), this packet should be discarded during step 2 because it's not a bubble or an ICMPv6 message! Do you think it's a self-contradiction, or just a difference of the word "MUST' and "should"?
    2. I want to implement the Teredo server (also with Teredo relay function, since the burden of a Teredo server is not too heavy) on the linux platform. Do you have some suggestion for us during our implementation? Any kind is appreciated. :-)
    3. Do you think it's reasonable to add mobility support to Teredo specification? You know I come from China, where most of the terminals behind NAT are GRPS terminals. I mean that maybe mobile users are the most urgent to get IPv6 connectivity bypass NAT(s) in the near future. I think about the mobility issue of Teredo service, but it seems too complicated. :-( Do you have some comment?
    
   P.S: Are there some guys still on the NGtrans mail-list? :-)
   Sincerely thanks!

Zhang haofeng
[email-masked]