* Fernando Gont: > On 01/04/2012 05:19 AM, Florian Weimer wrote: >>> Why should you drop in this case, when it's trivial to process these >>> fragments safely, with no side effects?? >> >> Do we really know that adding a fragment header to all outgoing packets >> does not cause them to be rejected? > > Are you arguing that IPv6 fragmentation does no work at all, or what?
I fear that it might work as well as in IPv4, that is, you can only get there with some effort, and for some nodes, it will never work. >> Could this be deployed at large DNS servers in a risk-free fashion, >> for instance? > > What's the specific question you're asking, and what is your concern, > specifically? If DNS servers started sending either atomic fragments or fragmented responses today (i.e., all generated packets carry an IPv6 extension header), would these servers become unreachable for some clients? (I think we have to assume the answer is "yes".) IPv4 is different in this regard because clients can opt out from fragmented responses by requesting 512 byte responses (even if it's technically a DNS protocol violation). This is just not possible with IPv6---unless the server keeps per-client state, which is a non-starter for large DNS server deployments. -- Florian Weimer <fwei...@bfk.de> BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstraße 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99 -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
