[Dnsmasq-discuss] stop-dns-rebind and IPv6

Mark Cross markcross.gpg.01 at gmx.com
Fri Sep 10 01:02:04 BST 2010

Jan 'RedBully' Seiffert wrote:

>> What IPv6 ranges need to be blocked? the IPv4-mapped ones obviously, but
>> ::1 also?

>> What about the fe80:: link-local addresses.
> I would say yes.

> sitelocal are deprecated (but better safe then sorry?),
> hmmm, what's with unique local?
I would propose this blocking:
    V4COMPAT        ::0/96
         "being deprecated is no longer valid, and that range
          includes the ::/0/128 and ::1/128 already. This will prevent
          older software from using such addresses at no connectivity
          cost (until this range gets reassigned)"
    LINKLOCAL       fe80::/10
    UNIQUELOCAL     fc00::/7
  Some unroutable addresses:
    DOCUMENT        2001:db8::/32
    BMWG            2001:0002::/48
    ORCHID          2001:10::/28	
  If the system has IPv6 assigned from the ISP, this addresses make no sense in the LAN:
    6TO4            2002::/16
    TEREDO          2001::/32
  If the address is (or):
    V4MAPPED        ::ffff:0:0/96
    BEHAVE          64:ff9b::/96  "Well Known Prefix"
       Extract the IPv4 address and do IPv4 testing:
          Any RFC1918     10/8, 172.16/12,192.168/16
          "This network"
          Link Local
          Multicast     maybe not?
          Future   Which includes

This addresses may? be also interesting to block, ( probably not?).
    MULTICAST    ff00::/8
    SITELOCAL    fec0::/10    (deprecated definition)


From: http://www.iana.org/assignments/ipv6-address-space/ipv6-address-space.xml
    V4COMPAT This definition has been deprecated by [RFC4291].
    SITELOCAL has been deprecated as of September 2004 [RFC3879].
    BEHAVE The "Well Known Prefix" 64:ff9b::/96

From: http://www.iana.org/assignments/ipv6-unicast-address-assignments/ipv6-unicast-address-assignments.xml
    DOCUMENT 2001:0DB8::/32  [RFC3849].
    6TO4     2002::/16  [RFC3056].
    TEREDO   2001::/32  [RFC4380].

From: http://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xml
   BMWG     2001:0002::/48
   ORCHID   2001:10::/28

Mark Cross

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