Regional Cisco Networking Academy Conference 2014

1© 2013 Cisco Systems, Inc. All rights reserved. Cisco confidential.Cisco Networking Academy, U.S./Canada

Regional Cisco Networking Academy Conference 2014

Giving you the knowledge and confidence to teach IPv6

DHCPv6-PD (Prefix Delegation) IPv6 Address Allocation to the Home

Rick GrazianiCS/CIS Instructor Cabrillo College


The World of IPv4 – DHCPv4 and NAT

• ISP only has to deliver a public IPv4 address for Home router interface.

• DHCPv4 and RFC 1918 private address space is used for home network.

• NAT is used for translation – but has its drawbacks!

• No NAT (like that… kind of) for IPv6

ISP HOME

Public IPv4 Addressfor the interface

G0/1 G0/1

10.0.0.0/8172.16.0.0/12192.168.0.0/16

G0/0

Private IPv4 Address

NAT

DHCPv4 DHCPv4


The World of IPv6 – DHCPv6-PD (Prefix Delegation)

• IPv6 End-to-end reachability:• Home network gets its own IPv6 prefix (public address)• No NAT

• ISP router is known as the Delegating Router (DR)• HOME router is known as the Requesting Router (RR)

ISP-DR HOME-RRG0/1 G0/1 G0/0

Complete IPv6 ReachabilityDelegating Router (DR)

Requesting Router (RR)

Global IPv6 Address Global IPv6 Address



After getting an IPv6 address on its ISP-facing interface, HOME-RR needs to:

Step 1: Request a Prefix for its LAN(s)

Step 2: Subnet the prefix for its LANs (optional) – Get a /48 but assign /64s

Step 3: Assign an IPv6 address from the prefix to its LAN interface

Step 4: Advertises the prefix in a Router Advertisement to devices on the LAN




Global IPv6 Address Global IPv6 Address



• First, HOME’s ISP facing interface needs an IPv6 address.

• Similar to any IPv6 client it may dynamically get an address using:• SLAAC - Using prefix in RA• Stateless DHCPv6 – Using prefix in RA and perhaps DNS address from DHCPv6 server• Stateful DHCPv6 - Like DHCPv4

• What about the address for the HOME LAN?

ISP-DR HOME-RR

IPv6 Address for the interface:• SLAAC • DHCPv6 (Stateful or Stateless)

G0/1 G0/1 G0/0



?



Step 1. HOME asks the ISP for an address to allocate for it’s LANs • DHCPv6-PD is initiated by the RR!

Step 2. ISP delegates an IPv6 prefix for HOME• Example: ISP sends HOME a /48 prefix

Step 3. HOME advertises prefix using SLAAC RA messages (currently only option)• HOME advertises the prefix out its interfaces using ICMPv6 Router Advertisement messages• HOME assigns the prefix or subnets of the prefix to one or more interfaces• Example: HOME interfaces are assigned /64 subnets from the /48 prefix


Delegating Router (DR)


DHCPv6-PD REQUEST

DHCPv6-PD REPLY with /48 prefix

RA with /64 prefix

G0/1 RA with /64 prefix

1

2

3

3


Our Example - DHCPv6-PD

• ISP will deliver an IPv6 address for HOME’s G0/1 interface using SLAAC

• ISP will delegate the 2001:DB8:AB00::/48 prefix to HOME to allocate to its LANs

• HOME will use the 2001:DB8:AB00:1::/64 subnet for its G0/0 interface.

• Assign :1 to the G0/0 interface

• G0/0 LAN will receive the 2001:DB8:AB00:1::/64 prefix and other information using SLAAC (RA).

ISP-DR HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

Router Advertisement2001:DB8:AB00:1::/64

Router Advertisement

2001:DB8:FEED:6::/64

DHCPv6Prefix Delegation

Prefix Delegation for the HOME

2001:DB8:AB00:/48

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

SLAACSLAAC


RA and DHCPv6-PD Messages

ISPDR

HOMERR

G0/1 G0/1 G0/0

SOLICIT: Prefix Delegation request

ADVERTISE

REQUEST

REPLY: Include Prefix

ICMPv6 Router Advertisement (RA)

The RR must be enabled with the PD option

In the case where the RR only has one DRthe rapid commit option omits these twosteps.

ICMPv6 Router Advertisement

ICMPv6 Router Solicitation

SLAAC

DHCPv6-PD

SLAACNote: If instead of SLAAC, HOME uses DHCPv6 for its G0/1 address, a separate set of DHCPv6 messages will be exchanged between the two routers.


HOME-RR Configuration

HOME-RR(config)# ipv6 unicast-routing ! Required to send RAHOME-RR(config)# interface gig 0/1HOME-RR(config-if)# ipv6 address autoconfig default ! Use RA & add defaultHOME-RR(config-if)# ipv6 dhcp client pd DHCPV6-PREFIX-FROM-ISP ! Request DHCPv6-PD. ! rapid-commit option ! can be used.HOME-RR(config)# interface gig 0/0HOME-RR(config-if)# ipv6 address DHCPV6-PREFIX-FROM-ISP 0:0:0:1::1/64 ! RA /48 from PD


HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

ISP-DR1

2001:DB8:FEED:6::/48

Router Solicitation

DHCPv6 PD Request

2

3


HOME-RR Configuration

HOME-RR(config)# interface gig 0/1HOME-RR(config-if)# ipv6 address autoconfig defaultHOME-RR(config-if)# ipv6 dhcp client pd DHCPV6-PREFIX-FROM-ISP HOME-RR(config)# interface gig 0/0HOME-RR(config-if)# ipv6 address DHCPV6-PREFIX-FROM-ISP 0:0:0:1::1/64 ! For G0/0 & RA

2001:DB8:AB00::/48 2001:DB8:AB00:1::/64 Router Advertisement

2 3

HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

ISP-DR

2001:DB8:AB00:1::1/64

First 48 bits replaced by the prefix received by DHCPv6-PD2001:DB8:AB00::

Subnet-ID Interface ID

DHCPv6 PD Request 1

DHCPv6 PD Reply

3


ISP-DR Configuration

HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

ISP-DR(config)# ipv6 unicast-routingISP-DR(config)# interface gig 0/1ISP-DR(config-if)# ipv6 address 2001:db8:feed:6::1/64ISP-DR(config-if)# ipv6 address fe80::feed:1 link-localISP-DR(config-if)# ipv6 dhcp server DHCPV6-CLIENT-ADDRESS ! Also a DHCPv6 server

ISP-DR(config)# ipv6 dhcp pool DHCPV6-CLIENT-ADDRESSISP-DR(config-dhcpv6)# prefix-delegation pool DHCPV6-PD-POOLISP-DR(config-dhcpv6)# dns-server 2001:DB8:AAAA::1

ISP-DR(config)# ipv6 local pool DHCPV6-PD-POOL 2001:DB8:AB00::/40 48

ISP-DRRouter

Advertisement2001:DB8:FEED:6::/

64Prefix Delegation for the HOME

2001:DB8:AB00:/64DHCPv6-PD

SLAAC For G0/1 interface

For HOME LANs

Pool can include address prefix command if stateful DHCPv6 is used instead of SLAAC.


ISP-DR Configuration

ISP-DR(config)# ipv6 dhcp pool DHCPV6-CLIENT-ADDRESSISP-DR(config-dhcpv6)# prefix-delegation pool DHCPV6-PD-POOL ! DHCPv6 address poolISP-DR(config-dhcpv6)# dns-server 2001:DB8:AAAA::1 ! DNS address for DHCPv6-PD

ISP-DR(config)# ipv6 local pool DHCPV6-PD-POOL 2001:DB8:AB00::/40 48 ! PD pool

Reserve a /40 to allocate addresses for ISP’s DHCPv6-PD clients2001:DB8:ABxx::/40 From the /40 each DHCPv6-PD client will get a /48

2001:DB8:AB00::/482001:DB8:AB01::/48 2001:DB8:AB02::/48 …2001:DB8:ABFF::/48

2001:DB8:AB00:1::/64 Router Advertisement

HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

ISP-DR

DHCPv6 PD Reply2001:DB8:AB00::/40

ipv6 address DHCPV6-PREFIX-FROM-ISP 0:0:0:1::1/64


Verifying DHCPv6-PD

ISP-DR HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1



2001:DB8:FEED:6::/64

DHCPv6Prefix Delegation

Prefix Delegation for the HOME

2001:DB8:AB00:/48

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

SLAACSLAAC


ISP-DR Verification

ISP-DR# show ipv6 dhcp interface gig 0/1GigabitEthernet0/1 is in server mode Using pool: DHCPV6-CLIENT-ADDRESS Preference value: 0 Hint from client: ignored Rapid-Commit: disabledISP-DR#

HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

ISP-DR

ISP-DR(config)# interface gig 0/1ISP-DR(config-if)# ipv6 dhcp server DHCPV6-CLIENT-ADDRESS



rapid-commit option not included


ISP-DR Verification

ISP-DR# show ipv6 local pool DHCPV6-PD-POOLPrefix is 2001:DB8:AB00::/40 assign /48 prefix1 entries in use, 255 available, 0 rejected0 entries cached, 1000 maximumUser Prefix Interface 00030001885A923B29E000040001 2001:DB8:AB00::/48 ISP-DR#

HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

ISP-DR

ISP-DR(config)# interface gig 0/1ISP-DR(config-if)# ipv6 dhcp server DHCPV6-CLIENT-ADDRESS



Other verification commands:• show ipv6 dhcp binding• show ipv6 dhcp interface


HOME-RR Verification

HOME-RR# show ipv6 inter briefGigabitEthernet0/0 [up/up] FE80::1 2001:DB8:AB00:1::1GigabitEthernet0/1 [up/up] FE80::8A5A:92FF:FE3B:29E1 2001:DB8:FEED:6:8A5A:92FF:FE3B:29E1HOME-RR#

HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

ISP-DR

HOME-RR(config)# ipv6 unicast-routing HOME-RR(config)# interface gig 0/1HOME-RR(config-if)# ipv6 address autoconfig default HOME-RR(config-if)# ipv6 dhcp client pd DHCPV6-PREFIX-FROM-ISP HOME-RR(config)# interface gig 0/0HOME-RR(config-if)# ipv6 address DHCPV6-PREFIX-FROM-ISP 0:0:0:1::1/64

SLAAC



HOME-RR# show ipv6 interface gig 0/0GigabitEthernet0/0 is up, line protocol is up General-prefix in use for addressing Global unicast address(es): 2001:DB8:AB00:1::1, subnet is 2001:DB8:AB00:1::/64 [CAL/PRE] <Output ommited> Hosts use stateless autoconfig for addresses.HOME-RR#

HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

ISP-DR





HOME-RR# show ipv6 routeIPv6 Routing Table - default - 7 entriesCodes: ND - ND Default, NDp - ND Prefix, DCE - Destination, NDr – Redirect

ND ::/0 [2/0] via FE80::FEED:1, GigabitEthernet0/1S 2001:DB8:AB00::/48 [1/0] via Null0, directly connected<Output omitted>HOME-RR#

HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

ISP-DR


Discard route

Default Route2001:DB8:AB00::/48X



PC> ipconfig

Windows IP Configuration

Ethernet adapter Local Area Connection:

IPv6 Address . . . . . . . . . . 2001:db8:ab00:1:1005:b37e:7e61:7ceb Link-local IPv6 Address. . . . . fe80::1005:b37e:7e61:7ceb Default Gateway. . . . . . . . . fe80::1

HOME-RRG0/1:1

G0/1:EUI-64

G0/0:1

2001:DB8:AB00:1::/642001:DB8:FEED:6::/64

ISP-DR


HOME-RR(config)# interface gig 0/0HOME-RR(config-if)# ipv6 address DHCPV6-PREFIX-FROM-ISP 0:0:0:1::1/64HOME-RR(config-if)# ipv6 address fe80::1 link-localFor a recognizable default gateway address


SLAACRouter(config)# ipv6 unicast-routingRouter(config-if)# no ipv6 nd suppress-ra ! This is the defaultStateless DHCPv6Router(config-if)# ipv6 nd other-config-flagRouter(config-if)# ipv6 dhcp server POOL-NAME

Router(config)# ipv6 dhcp pool POOL-NAMERouter(config-dhcpv6)# dns-server dns-addressRouter(config-dhcpv6)# domain-name domain-name

Stateful DHCPv6Router(config-if)# ipv6 nd managed-config-flagRouter(config-if)# ipv6 dhcp server POOL-NAME

Router(config)# ipv6 dhcp pool POOL-NAMERouter(config-dhcpv6)# address prefix ipv6-prefix/prefix-lengthRouter(config-dhcpv6)# dns-server dns-addressRouter(config-dhcpv6)# domain-name domain-name

DHCPv6-PD optionRouter(config-dhcpv6)# prefix-delegation pool ipv6-prefix/prefix-length ! Add to POOL-NAME

Router(config)# ipv6 local pool POOL-NAME ipv6-address-block/prefix-length subnet-prefix-length

Server ClientRouter AdvertisementRouter Advertisement

O=1Router Advertisement

M=1

To all DHCPv6 Servers


Server

DHCPv6Client(config-if)# ipv6 enable ! IPv6 link-local required to send DHCPv6 messagesClient(config-if)# ipv6 address dhcp

Client

Router as a DHCPv6 Client (Stateless or Stateful)

DR-facing Interface using SLAAC or DHCPv6Client(config-if)# ipv6 dhcp client pd POOL-NAME ! Request DHCPv6-PD

LAN-facing InterfaceClient(config)# ipv6 address POOL-NAME ::subnet-interfaceid-address/prefix-length

Router as a DHCPv6-PD Client

SLAACClient(config-if)# ipv6 address autoconfig [default] ! default option used for DHCPv6-PD

Router as SLAAC client


What we covered…• DHCPv4 – Remember IPv4?

• ICMPv6 – Used more than ICMPv4

• SLAACers – IPv6 Addressing without DHCPv6

• Stateless DHCPv6 – I have my address but need some other stuff

• Stateful DHCPv6 – Just like DHCPv4 (only different)

• DHCPv6-PD (Prefix Delegation) – IPv6 Prefix for the “home”


Web Site, Book, Etc.• Rick Graziani - [email protected]

• PowerPoints for CCNA, CCNP, IPv6• www.cabrillo.edu/~rgraziani• Username = cisco• Password = perlman

Shameless plug!

Quality time with my two

nieces…

mailto:[email protected]


http://www.cabrillo.edu/~rgraziani


And…… Thank you very much!Rick Graziani - [email protected]/~rgrazianiUsername = ciscoPassword = perlman


http://www.cabrillo.edu/~rgraziani

Documents

Regional Cisco Networking Academy Conference 2014