Francis, Thank you very much. Now I can be clear. Subsequent text was very important.
<draft-ietf-ipv6-2461bis-04.txt> 6.3.4. Processing Received Router Advertisements ------------------------------------------------------------------------ 2963 Stateless address autoconfiguration [ADDRCONF] may in some 2964 circumstances use a larger Valid Lifetime of a prefix or ignore it 2965 completely in order to prevent a particular denial of service attack. 2966 However, since the effect of the same denial of service targeted at 2967 the on-link prefix list is not catastrophic (hosts would send packets 2968 to a default router and receive a redirect rather than sending 2969 packets directly to a neighbor) the Neighbor Discovery protocol does 2970 not impose such a check on the prefix lifetime values. Similarly, 2971 [ADDRCONF] may impose certain restrictions on the prefix length for 2972 address configuration purposes. Therefore, the prefix might be 2973 rejected by [ADDRCONF] implementation in the host. However, the 2974 prefix length is still valid for on-link determination when combined 2975 with other flags in the prefix option. 2976 2977 Note: Implementations can choose to process the on-link aspects of 2978 the prefixes separately from the address autoconfiguration aspects 2979 of the prefixes by, e.g., passing a copy of each valid Router 2980 Advertisement message to both an "on-link" and an "addrconf" 2981 function. Each function can then operate independently on the 2982 prefixes that have the appropriate flag set. On Thu, 29 Sep 2005 09:12:45 +0200 Francis Dupont <[EMAIL PROTECTED]> wrote: > In your previous mail you wrote: > > I was confusing about valid lifetime. > > But <draft-ietf-ipv6-2461bis-04.txt> says, > the value 0 is just a special case. > > => you should read the whole subsection 6.3.4 because it is clear the > "on-link" function and "addrconf" function follow a different rule about > valid lifetime (2461bis text is about "on-link" and has no DoS issue, > 2462bis text is about "addrconf" and has the 2 hour rule). > > Regards > > [EMAIL PROTECTED] > ------------------------------------------------------------------------ Yukiyo Akisada <[EMAIL PROTECTED]> -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
