3. An IP address is a number used to
identify a computer on a network
Every computer on the net must have an
IP address
phone
TV
refrigerator
light
4. How many IP addresses
do we have?
The current version of IP (IPv4) has about
4 billion addresses
and about the same number of devices
So we are running out of IPv4 addresses
5. The Asia Pacific Network Information Centre
(APNIC) has reached the last block of
Internet Protocol version 4 (IPv4) addresses
in its available pool.
The remaining IPv4 space will be ‘rationed’
to network operators to be used as essential
connectivity with next-generation IPv6
addresses.
“From this day onwards, IPv6 is mandatory
for building new Internet networks and
services.” - APNIC Director General Paul Wilson
8. IPv6
IPv6 is the successor to IPv4
Defined in 1996
over 15 years ago
uses 128-bit addresses
more than enough for any conceivable
purpose
9. IPv6 Support
IPv6 is supported by all operating
systems
Windows
Linux
OS/X, iOS
Android, etc.
Supported by all router / switch
manufacturers
Cisco, Juniper, etc.
12. Why is IPv6 not in use?
Not supported by some low-end devices
Limitations in early support by Windows
XP, etc.
Some applications don't support it
The Main Reason?
I don't need to use it
15. What is NAT?
Network Address Translation
Computers in an organisation use private
IP addresses
e.g. beginning with 192.168.
A NAT translates these addresses into
one or more public IP addresses
100's of computers can use one public IP
address
16. NAT: Network Address Translation
rest of local network
Internet (e.g., home network)
10.0.0/24 10.0.0.1
10.0.0.4
10.0.0.2
138.76.29.7
10.0.0.3
All datagrams leaving local Datagrams with source or
destination in this network
ave same single source NAT IP address: 138.76.29.7,
different source port numbers have 10.0.0/24 address for
source, destination (as usual)
17. Problems with NAT
Breaks the core Internet concept of
"one device, one address"
Devices can't talk directly to one-another
No inbound services
Some applications won’t work
e.g. IPsec, WINS
18. Main Problem with NAT
Servers can't use NAT
they need to be accessible from outside
Need a public IP address for each server
or some kind of address sharing
So if you have lots of servers, you need
lots of IP addresses
where do you get them from?
19. Advantage of NAT
Devices can't be reached from outside
Better security
is it?
It is quite easy for hackers to get to NATTed
machines via e-mail, web, etc.
NAT provides only marginal security
20. Current Situation
No need for panic
ISPs in Sri Lanka have enough IPv4s to
last for another couple of years
21. Now
Only one or two addresses per customer
so what if you want to run five servers?
ADSL customers will have to share IPs
3G customers don't get a public IP even now
22. from Today
Major providers (Google, Facebook, etc.)
will be on IPv6.
and many others
major local sites to follow soon
Huge numbers of clients – starting from
China and Japan) will be on IPv6
They need to access you
You need to access them
24. Do Nothing
Use NAT for my clients
need one public IP
Use available public IPv4 for servers
may need to share addresses
beg your ISP for addresses
buy addresses
25. Do Nothing (cont.)
Need gateway to access v6 Internet
who provides it?
Need gateway for v6 clients to access
your servers
who provides it?
No direct device-to-device communication
may miss out on new services
26. Dual Stack
Run both v4 and v6 on your computers
Management is complicated
Performance and Security issues
27. v6-only Network
Need gateway to connect to v4 world
NAT64
Servers still need public IPv4 addresses
May be best solution for a new network
some applications may still not work
28. Dual Stack Servers and v4
Clients
Only a small number of servers, so easier
to manage dual stack
Your services are available to the entire
Internet
Clients go through NAT64
still can't use device-to-device services
29. Summary
IPv6 is here
Launched today
won't go away
Can't ignore it
maybe you can ignore it for a year
But will need to transition
