Chapter 8b
Intro to Routing & Switching

Upon completion of this chapter, you should be able
to:
 Describe the structure of an IPv4 address.
 Describe the purpose of the subnet mask.
 Compare the characteristics and uses of the unicast,
broadcast and multicast IPv4 addresses.
 Compare the use of public and private addresses.
 Explain the need for IPv6 addressing.
 Describe the representation of an IPv6 address.
 Describe types of IPv6 network addresses.
 Configure global unicast addresses.
 Describe multicast addresses.
 Describe the role of ICMP in an IP network.
 Use ping & traceroute to test network connectivity.
8.2.1

How to conserve the IP’s?

Tried NAT
Private IP addresses inside
network
 One or few public IP
addresses


Tried CIDR
Classless inter-domain
routing
 Subnetting a subnetted
address further


Came up with IPv6
8.2.1
 128

bits
8 sets (hextets) of four hex digits
 Ridiculous


Every device can have unique address
Eliminates IP conservation
 Written

amounts of addresses
in hex separated by :
FE22:00FF:002D:0000:0000:0000:3012:CCE3
 Rule
1: omit leading zeros
 Remove


00FF can be FF
0000 can be 0
 What

zeros before other hex digits
can this be reduced down to?
FE22:00FF:002D:0000:0000:0000:3012:CCE3
 Rule
 Use

2: omit all zero hextets
:: for multiple zero-value fields
FE22:00FF:002D:0000:0000:0000:3012:CCE3
 FE22:FF:2D::3012:CCE3
 Can

only do this once within address
Can’t tell how many fields it represents
 2001:0:0:34D0:0:0:9F77:2854


2001::34D0::9F77:2854
More examples next slide 
CAN NOT be…
 Incorrect

2001:0DB8::ABCD::1234
 What




address:
could it be???
2001:0DB8::ABCD:0000:0000:1234
2001:0DB8::ABCD:0000:0000:0000:1234
2001:0DB8:0000:ABCD::1234
2001:0DB8:0000:0000:ABCD::1234
 8.2.2.5

Practicing IPv6 Representations
Convert all 10 addresses into short form
 Handout

Reduce the IPv6 addresses to short form
 What
are 2 ways to shorten up an IPv6
address?


Omit all zero groups
Omit leading zeros
 How

128 bits
 An

A

IPv6 address is shown in what?
Hex
hextet is how many bits?
16 bits
 Each

many bits in an IPv6 address?
hextet is separated by what?
Colon :
8.2.3

Unicast


Multicast


One to a group
Anycast


One to one
DON’T WORRY
ABOUT IT!
There are NO MORE
BROADCASTS!
 Represents

Example: address assigned to your NIC
 Types




a single interface
of unicast addresses:
Global unicast- like a reg. IPv4 public address
Link-local- stays within LAN; not routable
Loopback- tests your NIC/if IP is working; ::1
Unique local- like NAT, unroutable
Global Unicast
Address
Link-local
Address
 Public

Similar to a public IPv4 address
 Begins

address
with 2000::
2001:: reserved for examples
 Every
NIC MUST have one
 Begin with FE80::
 For communicating within the LAN only




Unroutable
Auto-configured
Combo of FE80 and the MAC address
Also used between routers to exchange routing
tables & as next-hop IP addresses
 Tests
 ::1
TCP/IP on your NIC
 Like
IPv4, there are network & host portions
 Network ID is called prefix
 Represented at end by a slash

805B:2D9D:DC28:0000:0000:FC57:D4C8:1FFF/48
1st 48 bits

805B:2D9D:DC28::FC57:D4C8:1FFF/48
1st 48 bits

805B:2D9D:DC28:0:0:0:0:0/48 is Network ID

805B:2D9D:DC28::/48
 IPv6


Network ID (Prefix)
Subnet ID


has:
Identifies the subnetwork in your own network
Interface ID


Your MAC address
Like the host portion of IPv4 address
 8.2.3.5

Drag the IPv6 address type to its description.

Name 3 common types of IPv6 unicast addresses.


What are the 3 parts of an IPv6 address?


Prefix
Which part is identifiable in your network?


Prefix, subnet ID, interface ID
Which part identifies the network & will be the
same on every device in your network?


Global, link local, loopback
Subnet ID
Which part is the MAC address of your device?

Interface ID
8.2
 Dual

stack
Runs both IPv4 & IPv6 at
same time
 Tunneling

Sending an IPv6 packet
over IPv4 network
 Translation


NAT64
Translates the packets
from IPv4 to v6 & back
Ipv6 address
 Static
 Stateless
 DHCPv6
Address Autoconfiguration (SLAAC)
 Can
assign IP address by itself (without DHCP
server) based on info from router
 IPv6



router sends RA (router advertisements)
As a multicast, every 200 seconds
Or a PC can send a RS (router solicitation) asking
for address
These are ICMPv6 messages
 Have

to turn IPv6 routing on 1st
Router(config)# ipv6 unicast-routing
 What
is the term for running both IPv4 & IPv6
at the same time on your network?

Dual stack
 What
allows IPv6 packets to be sent over an
IPv4 network, between routers?

Tunneling
 What
process allows a host to automatically
get an IPv6 address from the router?

SLAAC
 What
address is created automatically for
inside the network communication?

Link local address
 The
link local (inside only) address begins
with what?

FE80
 The
global unicast address will begin with
what?

2000::
A
host getting an address from a router using
SLAAC sends and receives what?

RA and RS
 What
command will turn on IPv6 routing on a
Cisco router?

Router(config)# ipv6 unicast-routing
8.2
 What
command on a Cisco router will display
a short list of all the router interface’s IPv6
addresses?

Show ipv6 interface brief
 What
command on a Cisco router will display
the IPv6 routing table?

Show ipv6 route
 What
would the shortened version of this
IPv6 address be?
2001:0db8:0000:0000:0000:ff00:0042:8329

2001:db8::ff00:42:8329
8.2
One to a group
 Begin with FF00-FF02

Sent to all nodes on local-link
 Like an IPv4 broadcast


Two kinds:

Assigned




RS/RA messages
To predefined groups, like for DHCP
All nodes & all routers groups
Solicited node


Sent to devices that match the last 24 bits of address
For ARP requests!
 Lab


You will practice configuring IPv6 addresses on a
router, servers, and clients.
You will also practice verifying your IPv6
addressing implementation.
 Lab

8.2.5.3
8.2.5.4
Identify the Different Types of IPv6 Addresses;
Examine a Host IPv6 Network Interface and
Address; Practice IPv6 Address Abbreviation;
Identify the Hierarchy of the IPv6 Global Unicast
Address Network Prefix
 What
kind of message is NOT used in IPv6 but
used in IPv4?

Broadcasts
A
multicast IPv6 message is sent to all hosts
in a network. What will the address begin
with?

FF00-FF02
A
solicited node multicast is similar to what
kind of action in an IPv4 network?

ARP request
8.3
 For
both IPv4 & v6
 Echo request/reply
Is H2 reachable?
 Destination or host unreachable

Yes, I’m here!
Time exceeded (TTL)


IPv6 uses hop limit
When reaches 0, you get time exceeded message
 Has


some new features:
Router Solicitation message (RS)
Router Advertisement message (RA)
 More


new features:
Neighbor Solicitation message (NS)
Neighbor Advertisement message (NA)
 Shows

the path to destination
Tells if reachable
 TTL
field decreases going through each
router (hops)

When gets to 0, unreachable

An ICMP ping is the same on IPv4 & IPv6
networks. What 3 things does it test/tell you?


What kind of test is an echo request/reply?


Ping
What ICMP messages are exchanged during an
ARP request for IPv6?


RTT (time it takes to get there and back), if it’s
reachable, and route redistribution (better route
within network to take)
NS, NA
How would you test if TCP/IP is working on your
NIC?

Ping ::1
 What

test shows the path to a destination?
Traceroute
 What
happens when the TTL or hop count
gets to 0?

Network is unreachable
 How

does the TTL/hop count decrease?
Going through a router
 When
trying to get the destination MAC
address to send data, what kind of multicast
address is used in the NS message?

Solicited node multicast, FF00-FF02
 Complete
 Take
the study guide handout
the quiz on netacad.com
 Jeopardy
review
In this chapter, you learned:



There are three types of IPv6 addresses: unicast,
multicast, and anycast.
An IPv6 link-local address enables a device to
communicate with other IPv6-enabled devices on
the same link and only on that link (subnet).
Packets with a source or destination link-local
address cannot be routed beyond the link from
where the packet originated. IPv6 link-local
addresses are in the FE80::/10 range.
ICMP is available for both IPv4 and IPv6.
Chapter 8b
Intro to Routing & Switching