[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [RRG] Mobility considerations in proposal evaluation

On 28 feb 2008, at 15:29, William Herrin wrote:


For better or for worse, IPv4 bounds the box we're stuck with.
The endgame for IPv4 is about to start. No point wasting time on IPv4- 
specific solutions.



That's a remarkably persistent rumor but I asked my ISP and they set
me straight: for all the chatter there are more sightings of sasquatch
and the abominable snowman than there are of IPv6.


O really?

# tcpdump -p -c 100 -w /tmp/dumpfile port 53
# tcpdump -r /tmp/dumpfile ip6 | wc -l
reading from file /tmp/dumpfile, link-type EN10MB (Ethernet)
      10
# tcpdump -r /tmp/dumpfile ip | wc -l
reading from file /tmp/dumpfile, link-type EN10MB (Ethernet)
      90

So 10% of the DNS packets to/from my server are IPv6.


While I say that half-facetiously, it's really only half. IPv4 will be
with us for the foreseeable future. Focusing our efforts on IPv6 would
amount to counting our chickens before the hen finishes laying the
eggs.
Please read carefully. What I'm saying is that a solution that only works for IPv4 is a bad idea. And what you're saying is that a solution that only works for IPv6 is a bad idea. Before I go and disagree with that, please note that this leaves on the table all solutions that work with both IPv6 AND IPv4.
The average size of the address blocks the RIRs give out was 30320 addresses for IPv4 in 2007 (down from 35765 in 2005). Let's round this down to /18. There are currently 1099.4 million addresses left, that's 67k additional prefixes before we're out of IPv4 space. Or, a different calculation: we'll be out of IPv4 space in 5 years, global routing table growth is about 16% per year, 250k*1.16^5 ~= 500k. You can buy routers NOW that can (or at least claim to) handle 2 million. IPv4 will run out of addresses much faster than it will run out of routing slots.
IPv4 is a little over 25 years old now. This suggests that we'll have to live with IPv6 for several decades after we've made the transition, which gives us ample time to run into trouble with the routing table size. 

--
to unsubscribe send a message to rrg-request@psg.com with the
word 'unsubscribe' in a single line as the message text body.
archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg