How to configure IPV6 on a router
R1(config)#ipv6 unicast-routing /enables ipv6 routing on all interfaces
(isp prefix 48 bits) (subnet 16 bits) (Interface ID/host ID 64 bits)
R1(config-if)#ipv6 address 2233:0:2222:11:0000:0000:0000:0001/64
Note: can have ipv6 and an ipv4 address on one interface.
Show command:
show interfaces
show ipv6 interface fa0/0
show ipv6 interface brief
show ipv6 router connected
IPv6 Break down:
IPv4 address:
128.102.11.0 /24
128.102 is the network id portion
11 is the subnet id
0 is the host id
Class B address which is /16
Hosts in this case is easy: 32 – 24 = host bits = 8 = 2^8-2= 256-2= 254 hosts
Subnet 24-16 = 8 bits = 2^8 =256 subnets
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IPv6 similarities:
2233:0000:2222:0011:0000:0000:0000:0000/64
2233:0000:2222:0011 :0000:0000:0000:0000/64 being used.
(isp prefix 4 x 16 bit quartets( 0011 is subnet intranet)) (last 4 quartets is
interface ID/Host ID)
How to abbreviate IPv6:
Example: 2233:0000:2222:0011:0000:0000:0000:0000/64
2233:0000:2222:11:
2233:0:2222:11::/64
1. leading zero of a quartet can be omitted
2. All quartets can be abbreviated 0000 to :0:
3. 1 instance of multiple 0000:0000 to ::
Run show commands to see running-config and how you can dual IPv4 with IPV6 on same interface. Cool huh!
R1#show running-config /out put below.
——some out surpressed for ease of reading——
ipv6 unicast-routing
no ftp-server write-enable
!
!
!
!
!
!
!
interface Loopback0
no ip address
!
interface Ethernet0
description LAN inside$FW_INSIDE$
ip address 192.168.15.77 255.255.255.0
ip access-group 100 in
ip nat inside
ip virtual-reassembly
ipv6 address 2233:0:2222:11::1/64
no cdp enable
hold-queue 32 in
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Show command output here.
R5#sh ipv6 inter e0
Ethernet0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::213:C3FF:FE42:6B6D
Description: LAN inside$FW_INSIDE$
Global unicast address(es):
2233:0:2222:11::1, subnet is 2233:0:2222:11::/64
Joined group address(es):
FF02::1
FF02::2
FF02::1:FF00:1
FF02::1:FF42:6B6D
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds
ND advertised reachable time is 0 milliseconds
ND advertised retransmit interval is 0 milliseconds
ND router advertisements are sent every 200 seconds
ND router advertisements live for 1800 seconds
Hosts use stateless autoconfig for address
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Cold Memory:
FF02 is multicast of some sort
FE80 is Link-local address
Global Unicast :2233:0:2222:11::1, subnet is 2233:0:2222:11::/64
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R5#sho ipv6 inter brief
Ethernet0 [up/up]
FE80::213:C3FF:FE42:6B6D
2233:0:2222:11::1
Ethernet1 [up/down]
unassigned
Ethernet2 [down/down]
unassigned
FastEthernet1 [down/down]
unassigned
FastEthernet2 [up/up]
unassigned
FastEthernet3 [down/down]
unassigned
FastEthernet4 [down/down]
unassigned
Loopback0 [up/up]
unassigned
R5#
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R5#show ipv6 route connected
IPv6 Routing Table – 4 entries
Codes: C – Connected, L – Local, S – Static, R – RIP, B – BGP
U – Per-user Static route
I1 – ISIS L1, I2 – ISIS L2, IA – ISIS interarea, IS – ISIS summary
O – OSPF intra, OI – OSPF inter, OE1 – OSPF ext 1, OE2 – OSPF ext 2
ON1 – OSPF NSSA ext 1, ON2 – OSPF NSSA ext 2
C 2233:0:2222:11::/64 [0/0]
via ::, Ethernet0
R5#
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Practice Abbreviatiing IPv6
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example 1:
2233:0000:2222:0011:0000:0000:0000:0000:/64
2233:0:2222:11::/64
example 2:
2001:0050:0000:0000:0000:0AB4:IE2B:98AA/128
2001:0050::0AB4:IE2B:98AA/128
2001:50::AB4:IE2B:98AA/128
example 3:
1234:1234:0000:0000:0000:0000:3456:3434 /128
1234:1234::3456:3434/128
Types of casts:
(**broadcast is not longer used in IPv6**)
Unicast- 1 to 1
Multicast – 1 to specfic many (example: FF00::/8
Anycast -1 to closest device
Types of addresses ipv6:
Global Unicast – similar to Public IP from the ISP
Link-Local Similar to the MAC address (FE80)
FE80:AAAA.AAAA.AAAA (FE80 + Mac address)
Site-Local Private addressesing side (FEC0)
Loopback are all 0s and then a 1 like this (::1/128 )
no broadcast in IPv6 any more..
Note: advantage of IPv6 is route summarizing
IPv4 compatible
1st 96 bits used last 16 bits for ipv6 compatible:
ipv6:
1 90:4E 71
D1 = 209
90 = 144
4E = 78
71 = 113 Hex
0-9 = 0 – 9
256 | 16 | 1 A-F = 10 – 15
——————–
D 1 = 209
ipv4 compatible:
209.144.78.113
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DHCP or Autoconfiguration IPv6 world –RFC 2462 excerpts from below…
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Autoconfiguration:
Stateful - DHCPv6 autoconfiguration – obtian Ipv6 address via server
In the stateful autoconfiguration model, hosts obtain interface
addresses and/or configuration information and parameters from a
server. Servers maintain a database that keeps track of which
addresses have been assigned to which hosts. The stateful
autoconfiguration protocol allows hosts to obtain addresses, other
configuration information or both from a server. Stateless and
stateful autoconfiguration complement each other. For example, a host
can use stateless autoconfiguration to configure its own addresses,
but use stateful autoconfiguration to obtain other information.
Stateful autoconfiguration for IPv6 is the subject of future work
Stateless - Static – local host creates its own LINK-Local address
IPv6 defines both a stateful and stateless address autoconfiguration
mechanism. Stateless autoconfiguration requires no manual
configuration of hosts, minimal (if any) configuration of routers,
and no additional servers. The stateless mechanism allows a host to
generate its own addresses using a combination of locally available
information and information advertised by routers. Routers advertise
prefixes that identify the subnet(s) associated with a link, while
hosts generate an “interface identifier” that uniquely identifies an
interface on a subnet. An address is formed by combining the two. In
the absence of routers, a host can only generate link-local
addresses. However, link-local addresses are sufficient for allowing
communication among nodes attached to the same link.
How host creates link-local address:
Host sends out (NS) neighbor solicitations to check to see if anyone else is using this link-local address.
NS destination address FF02::1 is a multicast to ALL Nodes!
if NS finds a match of some host using same address host responds with NA neighbor advertisment from responding Host A (NA). The NS host will disable its link-local and retry another link-local address.
So host A sends out NS to host B host B sends back NA host A recalculates link-local address and retries its NS messages until it doesnt find a similar link-local address.
Process is call DAD Duplicate Address Detetection
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Just the basics for Ipv6
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