CCNAv5.0: Tech Updates
& IPv6 (Introduction to
Networks)
Fernando Velez Varela
LMC ASC/ITC/CA PUJ Cali
Julio de 2013
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Agenda
IPv6 in Introduction to
Networks
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Chapter Routing Protocols
1 Routing Concepts
2 Static Routing
3 Routing Dynamically
4 EIGRP
4.1 Characteristics of EIGRP
4.2 Operation of EIGRP
4.3 Configuring EIGRP for IPv4
4.4 Configuring EIGRP for IPv6
5 Advanced EIGRP Configurations
6 Single-Area OSPF
6.1 Characteristics and Operation of OSPF
6.2 Configuring Single-area OSPFv2 for IPv4
6.3 Configuring Single-area OSPFv3 for IPv6
7 Adjust and Troubleshoot Singles-Area OSPF
8 Multi-Area OSPF
Integrate IPv6 content with IPv4
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• Monday, 31st January, 2011, IANA allocated 2 IPv4 blocks to APNIC, the RIR-ul for Asia Pacific
• This event brought IANA to the decission of allocating the rest of the 5 spaces to each of the 5
RIRs
• So, practically,
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• 128 bits
Right now we are making /64 allocations to end-users (small alarm signal)
• Are we getting rid of NAT?
Unfortunately, no
Over time NAT has imposed itself as a false sense of security and comfort in
enterprises – it is being requested to exist in the industry
• Autoconfiguration
The posibility of a host to completely autoconfigure a 128 bit IPv6 global address
to communicate withing its subnet
Great security risks
You lose the possibility of clear, local accounting in a network
(omg! IPsec end-to-end!)
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• The RIRs get /12
• The ISPs get /32
• Organisations get /48 from the ISP
• The next 16 bits can be subnetted to obtain a maximum of 2^16
different subnets
• The last 64 bits are used for the host portion
Global routing prefix Subnet Interface ID
64 bits
min 16 bits max 48 bits
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• Is an address that starts with FEB7 a link-local address?
R: Yes, just the first 10 bits need to be the same
Adresă Rol
Global unicast 2000::/3 Unicast
Unique local FD00::/8 Private IP space
Link-local FE80::/10
Communication in the same
segment
Multicast FF00::/8 Transmiting to a group
Anycast
It can be anything from
the unicast space
Using the same address to
identify multiple hosts in the
Internet
Broadcast ???
None. The Internet hates
broadcasts.
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• An IPv6 address is 128 bits long
• An IPv6 address is expressed in hexadecimal (1…9AB..F)
• How is an IPv6 address going to look?
2023:0000:34FA:D56E:9892:09C1:4322:AA43
2023
How many bits?
= 16 (group)
:
Delimiter
0000:34FA:D56E:9892:09C1:4322:AA43
A bit long
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• Successive fields of 0’s can be represented as “::”, but only once in an
address
• The leading zeros from the beginning of a hexa group can be omitted.
• A group of four 0s can be written as one single hexa-digit of 0
• Example:
2023:0000:34FA:0000:0000:09C1:4322:AA43
→ 2023:0000:34FA::09C1:4322:AA43 Correct
→ 2023:0:34FA::9C1:4322:AA43 Correct
→ 2023::34FA:0:0:9C1:4322:AA43 Correct
→ 2023::34FA::9C1:4322:AA43 Incorrect
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IPv6 Address Types
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Prefix Hex Value Use
0000 to 00FF •Unspecified
•Loopback
•IPv4-compatible
0100 to 01FF Unassigned (0.38 % of IPv6 space)
0200 to 03FF NSAP Network Service AP)
0400 to 1FFF Unassigned (~11% of IPv6 space)
2000 to 3FFF Aggregatable global unicast
(12.5%)
4000 to FE7F (Huge) Unassigned (~75% of IPv6 space)
FE80 to FEBF Link-local
FC00 to FCFF Unique-local
FF00 to FFFF Multicast
Note: IPv6 Internet uses 2001::/3 which is < 2% of IPv6 address space
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IPv6 Address Description
::/0
• All networks and used when specifying a default static
route.
• It is equivalent to the IPv4 quad-zero (0.0.0.0)
::/128
• Unspecified address and is initially assigned to a host
when it first resolves its local link address
::1/128
• Loopback address of local host
• Equivalent to 127.0.0.1 in IPv4
FE80::/10
• Link-local unicast address
• Similar to the Windows autoconfiguration IP address of
169.254.x.x
FF00::/8 • Multicast addresses
All other addresses • Global unicast address
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• Equivalent to 127.0.0.1 in IPv4
• An address used when a host “talks to
itself”
Network Services
• The loopback address in IPv6 is:
0:0:0:0:0:0:0:1/128
OR?
::1/128
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IPv6 Unicast
Address Assignment
Link-local (FE80::/10)
Address Assignment
Static
IPv6 Address
Dynamic
Automatically created
(EUI-64 format) if a
global unicast IPv6
address is configured
Global Routable
Address Assignment
Static
IPv6 Address
IPv6 Unnumbered
Dynamic
Stateless
Autoconfiguration
DHCPv6
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• Link-local addresses play a crucial role in the operation of IPv6.
• They are dynamically created using a link-local prefix of FE80::/10
and a 64-bit interface identifier.
128 bits
FE80
1111 1110 1000 0000 0000 0000 ... 0000 0000 0000
Interface ID
/10
FE80::/10
/64
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R2# ping FE80::202:16FF:FEEB:3D01
Output Interface: serial0/0/0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to FE80::202:16FF:FEEB:3D01, timeout is 2
seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 31/34/47 ms
• When pinging another device using a link-local address, the
outgoing interface must be specified.
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R1# show ipv6 interface loopback 100
Loopback100 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::222:55FF:FE18:7DE8
No Virtual link-local address(es):
Global unicast address(es):
2001:8:85A3:4290:222:55FF:FE18:7DE8, subnet is 2001:8:85A3:4290::/64 [EUI]
Joined group address(es):
FF02::1
FF02::2
FF02::1:FF18:7DE8
MTU is 1514 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
ND DAD is not supported
ND reachable time is 30000 milliseconds (using 31238)
Hosts use stateless autoconfig for addresses.
R1#
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• A global unicast address is an IPv6 address from the global public
unicast prefix (2001::/16).
• These addresses are routable on the global IPv6 Internet.
• Global unicast addresses are aggregated upward through
organizations and eventually to the ISPs.
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• The global unicast address consists of:
• A 48-bit global routing prefix
• A 16-bit subnet ID
• A 64-bit interface ID
Global Routing Prefix
Subnet
ID Interface ID
2001
0010
0008 21B:D5FF:FE
