[kictanet] [Fwd: Signing of the ARPA zone]

[Michuki Mwangi]

Hi Okech,

JM Okech wrote:
> Sorry Michuki, Listers,
> Just wondering .... from the document that you directed us together with
> the content of your mail it appears like we only have 12 root servers.
> My undersstanding that we have 13 root servers (interms of the allowable
> IP address) kindly clarify this....
>

There are 13 noted with letters A - M unless your page did not load
completely please check and confirm.

The limitation was as a result of the maximum DNS UDP packet size. The
size set at 512bytes therefore has a limit on the amount of information
that can be carried at any given time.

Therefore using a short naming format "a.root-servers.net"  plus the
IPv4 address space it was only possible to fit in 13 of them.

This has since changed. With the introduction of IPv6 glue for the
Root-Servers and soon the DNSSEC information, there was need for a
review of this limitation.

EDNS0 allows DNS to pass through packets beyond 512bytes. However due to
legacy systems and installations it does not work very well as these
systems tend to block or drop DNS packets beyond 512bytes.

The Wikipedia explanation for EDNS0 should give you the finer details of
how it works. http://en.wikipedia.org/wiki/Extension_mechanisms_for_DNS

Regards,

Michuki.