Transcript IP next generation, (IPv6)

IP Next Generation (IPv6)
• what?
• why?
• when?
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Why IPng?
• the limited availability of IPv4
addresses
– classless routing is the way to the 21st century
• routing is not hierarchical
– lots of routers, network structures are
complicated
• awkward address management in
large networks
– the fight for space between the subnet bits and
host bits
• no obligatory data security features
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The Run for the IPng
Simple
CLNP
TUBA
IP Encaps
IPAE
CNAT
PIP
Nimrod
SIP
SIPP
SIP
TP/IX
1992
CATNIP
1993
1994
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IPv6 (SIPP-16)
• some of the header fields omitted
• new features with new headers
• hierarchical addresses
– so many that in the early stages only a minor
portion of the address space is reserved
– IPv4, multicast and anycast addresses
– “plug and play” for workstations
• flow labels and priority
– to support the QoS features
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SIPP 16 Header
0
IPv4:
20 bytes
+ options (rare)
15 16
identification
flags
protocol
fragment offset
header checksum
destination address
additional parameters
0
• hop-by-hop option
• source routing
• fragmentation
• tunnelling
• authentication/encryption
total length
source address
• source routing
IPv6:
40 bytes
+ options (common)
service
version hdr length
time to live
31
filler
15 16
version
class
payload length
31
flow label
next header
max hops
source address (128 bits)
destination address (128 bits)
next header
option specific data n bytes
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Important when Assigning
Addresses
• the encoding of topological
information
• geographical information
• mesh structures, multi-homing
• methods of assigning host numbers
• growing the hierarchy
• multicast addresses
• addresses for mobile hosts
• other protocols (also IPv4)
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IPv6 Addresses
FEDC:BA98:7654:3210:FEDC:BA98:7654:3210
x::y
::a.b.c.d
the area between filled with zeroes
the encoding of an IPv4 address
::0
::1
an undefined address
“myself”, loopback
FE80::interface ID
local)
FEC0::subnet:interface ID
a network separated by routers (link-
FF...
FF02::1
FF02::2
multihost address
equivalent to broadcast; all hosts
all routers (within a network)
internal for an organization (site-local)
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(Possible) IPv6 Internet
Addresses
128
112 104
001
TLA
RES
80
NLA*
64
SLA*
• 001, Format Prefix (FP)
– indicates the global hierarchical
address
• TLA, Top Level Aggregator
–
–
top level network link
max. 8 192
• NLA, Next Level Aggregator
– a teleoperator or a major
customer
– consists of several n bit fields
– max. 16 777 216 (8 bits reserved)
0
Interface ID
• SLA, Site Level Aggregator
– organization subnet information
– several levels if necessary
– max. 65 536
• Interface ID
– IEEE EUI-64, 64 bits
– usually a 48 bit MAC
address in EUI-64 format
– max. 18 446 744 073 709 551 616
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Neighbor Discovery
• router discovery
• prefix discovery
• parameter discovery
• address determination
• next hop determination
• address resolution
• duplicate address detection
• unreachability detection
• redirect
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Neighbor Solicitation
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Neighbor Advertisement
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The IPv4 -> IPv6 Translation
• IPv4 and/or IPv6/v4 nodes will not become isolated
• at first IPv6 traffic will be tunnelled
• IPv4 IPv6 only in tunnels
– example: an IPv6/v4 compatible firewall host
IPv6/v4
IPv6/v4
B
IPv6/v4
F
C
E
IPv6/v4
D
IPv4
G
A
IPv6/v4
IPv4
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IPv6 development
subcategories:
• IPv6
• transition
• autoconfiguration DNS FTP
• address allocation
TCP
• security
• routing
ICMP
IP
???
?
IPv6
SIPP-16
1995
1996
1997
1998
1999
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6bone backbone (LANCS)
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Testing Address Hierarchy
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Further Information on IPv6
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