Intro to IPv6

The Basics of IPv6 / EIGRP Routing

IPv6 Address Notation

128-bit IPv6 addresses are represented in:

Eight 16-bit segments

Hexadecimal (non-case sensitive) between 0000 and FFFF

Separated by colons

Example:

– 3ffe:1944:0100:000a:0000:00bc:2500:0d0b

One Hex digit = 4 bits

Rule 1: Leading 0’s

Two rules for reducing the size of written IPv6 addresses.

The first rule is:

The leading zeroes in any 16-bit segment do not have to be written.

Example

– 3ffe : 1944 : 0100 : 000a : 0000 : 00bc : 2500 : 0d0b

– 3ffe : 1944 : 100 : a : 0 : bc : 2500 : d0b

Rule 2: Double colon :: equals 0000…0000

The second rule can reduce this address even further:

Any single, contiguous string of one or more 16-bit segments consisting of all zeroes can be represented with a double colon.

ff02 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0005

ff02 : 0 : 0 : 0 : 0 : 0 : 0 : 5

ff02 : : 5

ff02::5

Network Prefixes

IPv4, the prefix—the network portion of the address—can be identified by a dotted decimal netmask or bitcount.

255.255.255.0 or /24

IPv6 prefixes are always identified by bitcount (prefix length).

Prefix length notation:

3ffe:1944:100:a::/64

16 32 48 64 bits

All 0’s IPv6 Address All zeroes IPv6 address can be written with a double colon ::

There are two cases where an all-zeroes address is used.

1. Default address, address is all zeroes and the prefix length is zero:

::/0

2. Unspecified address, which is used in some Neighbor Discovery Protocol procedures (later).

An unspecified address is a filler, indicating the absence of a real IPv6 address.

When writing an unspecified address, it is differentiated from a default address by its prefix length:

::/128

IPv6 Loopback Address

Equivalent to 127.0.0.1 in IPv4

This address is used when a host talks to itself.

Loopback or Local Host Address

0:0:0:0:0:0:0:1/128

or

::1/128

Three types of IPv6 Addresses

The three types of IPv6 address follow:

1. Unicast

Global Unicast

Globally unique

Routed globally with no modification

Link Local Unicast

Unique Local Address

2. Multicast

3. Anycast

Unlike IPv4, there is no IPv6 broadcast address.

There is, however, an "all nodes" multicast address, which serves essentially the same purpose as a broadcast address.

Prefix Designation and Explanation IPv4 Equivalent

ff00::/8

Example: ff01:0:0:0:0:0:0:2

MulticastThese addresses are used to identify multicast groups.

They should only be used as destination addresses, never as source addresses.

224.0.0.0/4

fe80::/10

Example: fe80::200:5aee:feaa:20a2

Link-Local AddressesThese addresses are used on a single link or a non-routed common access network, such as an Ethernet LAN.

They do not need to be unique outside of that link.

Routers must not forward IPv6 packets if the source or destination contains a link-local address.

169.254.0.0/16

Link-Local Scope Multicast Addresses

Subnetting IPv6

A typical IPv6 site prefix will be /48

This creates a 16 bit subnet part of the address structure

Allows for 216, or 65,536, subnets!

There are no concerns about needing an all 0’s or all 1’s subnet in IPv6!

64 bit host field allows for 264 hosts per subnet.

More than 1,000,000,000,000,000,000 addresses per subnet.

Allows of the automatic IPv6 address assignment features to work well (later).

2340:1111:AAAA::/48

Subnetting IPv6

4 specific subnets to be used inside Company1:

– 2340:1111:AAAA:0001::/64

– 2340:1111:AAAA:0002::/64

– 2340:1111:AAAA:0003::/64

– 2340:1111:AAAA:0004::/64

Note: A valid abbreviation is to remove the 3 leading 0’s from the last shown quartet.

– 2340:1111:AAAA:1::/64

/64

IPv6 Routing Protocols

Exactly the same as IPv4 routing protocols only different.

IPv6 Static routes

OSPFv3 (defined in RFC 5340, OSPF for IPv6)

EIGRP for IPv6

RIP next generation (RIPng) (defined in RFC 2080, RIPng for IPv6)

Multiprotocol Border Gateway Protocol Version 4 (MP-BGP4 or MBGP) (defined in RFC 2545, Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing, and RFC 4760, Multiprotocol Extensions for BGP-4)

ipv6 unicast-routing

ipv6 unicast-routing global configuration command

Enables IPv6 routing

Required before any ipv6 routing protocol can be configured

ipv6 router rip name command

Enables IPv6 rip routing

R1(config)# ipv6 router rip luigi% IPv6 routing not enabledR1(config)# ipv6 unicast-routing R1(config)# ipv6 router rip luigiR1(config-rtr)#

R1 (Example configuration)

ipv6 unicast-routing

interface FastEthernet0/0 no ip address ipv6 address 2340:1111:AAAA:101::1/64!interface Serial0/0/0 no ip address ipv6 address 2340:1111:AAAA:A01::1/64 clock rate 64000!interface Serial0/0/1 no ip address ipv6 address 2340:1111:AAAA:A03::1/64

VerifyR1# show ip inter briefInterface IP-Address OK? Method Status ProtocolFastEthernet0/0 unassigned YES unset up up

FastEthernet0/1 unassigned YES unset administratively down down

Serial0/0/0 unassigned YES unset up up

Serial0/0/1 unassigned YES unset up up

R1#

R1# show ipv6 inter briefFastEthernet0/0 [up/up] FE80::21B:CFF:FEC2:82D8 2340:1111:AAAA:101::1FastEthernet0/1 [administratively down/down]Serial0/0/0 [up/up] FE80::21B:CFF:FEC2:82D8 2340:1111:AAAA:A01::1Serial0/0/1 [up/up] FE80::21B:CFF:FEC2:82D8 2340:1111:AAAA:A03::1R1#

Verify

R1 #ping 2340:1111:AAAA:0A01::2

Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 2340:1111:AAAA:A01::2, timeout is 2

seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 msR1#

VerifyR1# debug ipv6 packetIPv6 unicast packet debugging is onR1# ping 2340:1111:AAAA:0A01::2

Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 2340:1111:AAAA:A01::2, timeout is 2

seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 msR1#*Jun 19 16:19:13.181: IPv6: SAS picked source 2340:1111:AAAA:A01::1 for

2340:1111:AAAA:A01::2 (Serial0/0/0)*Jun 19 16:19:13.181: IPV6: source 2340:1111:AAAA:A01::1 (local)*Jun 19 16:19:13.181: dest 2340:1111:AAAA:A01::2 (Serial0/0/0)*Jun 19 16:19:13.181: traffic class 0, flow 0x0, len 100+0, prot 58,

hops 64, originating

Jun 19 16:19:13.241: IPV6: source 2340:1111:AAAA:A01::2 (Serial0/0/0)*Jun 19 16:19:13.241: dest 2340:1111:AAAA:A01::1*Jun 19 16:19:13.241: traffic class 0, flow 0x0, len 100+4, prot 58,

hops 64, forward to ulp

R1# un all

ICMPv6

Default Static Route

IPv6 default static route, which is equivalent to IPv4 ip route 0.0.0.0 0.0.0.0

Router(config)# ipv6 route ::/0 serial 0/0/0

Router(config)# ipv6 route ipv6-prefix/prefix-length {ipv6-address | interface-type interface-number [ipv6-address]} [administrative-distance] [administrative-multicast-distance | unicast | multicast] [next-hop-address] [tag tag]

Static Routes: ExampleR1(config)# ipv6 route 2340:1111:AAAA:0102::/64 ser 0/0/0

R1# show ipv6 route<output omitted>S 2340:1111:AAAA:102::/64 [1/0] via ::, Serial0/0/0C 2340:1111:AAAA:A01::/64 [0/0] via ::, Serial0/0/0

R2(config)# ipv6 route 2340:1111:AAAA:0101::/64 2340:1111:AAAA:0A01::1

R2# show ipv6 route<output omitted>S 2340:1111:AAAA:101::/64 [1/0] via 2340:1111:AAAA:A01::1

R2# ping 2340:1111:AAAA:0101::1Sending 5, 100-byte ICMP Echos to 2340:1111:AAAA:101::1, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 msR2#

Static Routes: Propagated w/ RIP

• ipv6 rip name default-information originate

• Example:

Router(config-if)# ipv6 rip process1 default-information originate

EIGRP for IPv6

EIGRP vs EIGRP for IPv6EIGRP IPv4 IPv6

Advertises routes for… IPv4 IPv6

Layer 3 protocol for EIGRP messages IPv4 IPv6

Layer 3 header protocol type 88 88

UDP Port N/A N/A

Uses Successor, Feasible Successor yes yes

Uses Dual yes yes

Supports VLSM yes yes

Can perform automatic summarization yes N/A

Uses triggered updates yes yes

Default metric bandwidth and delay yes yes

Multicast Update destination 224.0.0.10 FF02::10

Authentication EIGRP-specific IPv6 AH/ESP

EIGRP for IPv6

Available in Cisco IOS Release 12.4(6)T and later

EIGRP for IPv4 and IPv6 are configured and managed separately although many of the commands are similar.

EIGRP for IPv6 is configured on a per-interface basis, no network command is used.

EIGRP for IPv6 has a shutdown feature which is the default state.

EIGRP for IPv6 does not do automatic summarization like EIGRP for IPv4.

EIGRP for IPv6 sues the neighbors link-local address as the next-hop IP address (neighbor table, topology table, routing table).

EIGRP for IPv6 does not require neighbors to be in the same IPv6 subnet to become neighbors.

EIGRP for IPv6

EIGRP Router ID decision steps based on IPv4 configuration:

1. Use the configured value (using the eigrp router-id a.b.c.d EIGRP subcommand under the ipv6 router eigrp command)

2. Use the highest IPv4 address on an up/up loopback interface

3. Use the highest IPv4 address on an up/up non-loopback interface

Note: In an IPv6 only environment the eigrp router-id command must be used otherwise the router will not form any EIGRP adjacencies.

IOS lets you stop and start the EIGRP process with the shutdown and no shutdown router mode subcommands.

After initial configuration, the EIGRP for IPv6 process starts in shutdown mode,

To start the EIGRP process it is required to issue the no shutdown

Configuring R1

EIGRP for IPv6 is configured on the interfaces.

There are no network commands

R1(config)# inter fa 0/0R1(config-if)# ipv6 eigrp 100

R1(config)# inter ser 0/0/0R1(config-if)# ipv6 eigrp 100

R1(config)# inter ser 0/0/1R1(config-if)# ipv6 eigrp 100

Routing Table…

There are no EIGRP IPv6 routes in the routing table... yet.

R1# show ipv6 routeIPv6 Routing Table - 8 entries<output omitted> D - EIGRP, EX - EIGRP externalC 2340:1111:AAAA:101::/64 [0/0] via ::, FastEthernet0/0L 2340:1111:AAAA:101::1/128 [0/0] via ::, FastEthernet0/0C 2340:1111:AAAA:A01::/64 [0/0] via ::, Serial0/0/0L 2340:1111:AAAA:A01::1/128 [0/0] via ::, Serial0/0/0C 2340:1111:AAAA:A03::/64 [0/0] via ::, Serial0/0/1L 2340:1111:AAAA:A03::1/128 [0/0] via ::, Serial0/0/1L FE80::/10 [0/0] via ::, Null0L FF00::/8 [0/0] via ::, Null0

Show ipv6 protocols

There is an EIGRP 100 for IPv6 process but the interfaces are not yet enabled for EIGRP IPv6 because the process is shutdown.

R1# show ipv6 protocolsIPv6 Routing Protocol is "connected"IPv6 Routing Protocol is "static"IPv6 Routing Protocol is "eigrp 100" EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0 EIGRP maximum hopcount 100 EIGRP maximum metric variance 1 Interfaces: Redistribution: None Maximum path: 16 Distance: internal 90 external 170

R1# show ipv6 eigrp neighborsIPv6-EIGRP neighbors for process 100% EIGRP 100 is in SHUTDOWNR1#

Enabling EIGRP for IPv6

The EIGRP for IPv6 process must be enabled with the no shutdown command.

R1(config)# inter fa 0/0R1(config-if)# ipv6 eigrp 100

R1(config)# inter ser 0/0/0R1(config-if)# ipv6 eigrp 100

R1(config)# inter ser 0/0/1R1(config-if)# ipv6 eigrp 100

<The commands above were already completed>

R1(config)# ipv6 router eigrp 100R1(config-rtr)# router-id ? A.B.C.D EIGRP Router-ID in IP address format

R1(config-rtr)# router-id 1.1.1.1R1(config-rtr)# no shutdown

Verifying

The EIGRP for IPv6 process has been enabled but we don’t have any neighbors... yet.

R1# show ipv6 protocols IPv6 Routing Protocol is "connected"IPv6 Routing Protocol is "static"IPv6 Routing Protocol is "eigrp 100" EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0 EIGRP maximum hopcount 100 EIGRP maximum metric variance 1 Interfaces: FastEthernet0/0 Serial0/0/0 Serial0/0/1 Redistribution: None Maximum path: 16 Distance: internal 90 external 170

R1# show ipv6 eigrp neighborsIPv6-EIGRP neighbors for process 100

Verifying

Notice that EIGRP for IPv6 uses link-local addresses to exchange EIGRP messages.

R1# show ipv6 eigrp neighborsIPv6-EIGRP neighbors for process 100H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num1 Link-local address: Se0/0/1 12 00:05:18 40 240 0 16 FE80::30 Link-local address: Se0/0/0 11 00:08:35 31 200 0 8 FE80::2R1#

EIGRP for IPv6 Topology Table

.

R1# show ipv6 eigrp topologyIPv6-EIGRP Topology Table for AS(100)/ID(1.1.1.1)Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 4444:0:0:4001::/64, 1 successors, FD is 2684416 via FE80::3 (2684416/2172416), Serial0/0/1P 2340:1111:AAAA:103::/64, 1 successors, FD is 2172416 via FE80::3 (2172416/28160), Serial0/0/1P 2340:1111:AAAA:A03::/64, 1 successors, FD is 2169856 via Connected, Serial0/0/1P 2340:1111:AAAA:B02::/64, 1 successors, FD is 2681856 via FE80::3 (2681856/2169856), Serial0/0/1P 2340:1111:AAAA:A02::/64, 1 successors, FD is 2681856 via FE80::2 (2681856/2169856), Serial0/0/0P 2340:1111:AAAA:102::/64, 1 successors, FD is 2172416 via FE80::2 (2172416/28160), Serial0/0/0P 2340:1111:AAAA:B01::/64, 1 successors, FD is 2681856 via FE80::3 (2681856/2169856), Serial0/0/1P 2340:1111:AAAA:A01::/64, 1 successors, FD is 2169856 via Connected, Serial0/0/0P 2340:1111:AAAA:101::/64, 1 successors, FD is 28160 via Connected, FastEthernet0/0R1#

IPv6 Routing Table

Link-local address is next-hop address

R1# show ipv6 routeIPv6 Routing Table - 14 entriesCodes: C - Connected, L - Local, S - Static, R - RIP, B - BGP <output omitted> D - EIGRP, EX - EIGRP externalC 2340:1111:AAAA:101::/64 [0/0] via ::, FastEthernet0/0L 2340:1111:AAAA:101::1/128 [0/0] via ::, FastEthernet0/0D 2340:1111:AAAA:102::/64 [90/2172416] via FE80::2, Serial0/0/0D 2340:1111:AAAA:103::/64 [90/2172416] via FE80::3, Serial0/0/1<output omitted>D 2340:1111:AAAA:B01::/64 [90/2681856] via FE80::3, Serial0/0/1D 2340:1111:AAAA:B02::/64 [90/2681856] via FE80::3, Serial0/0/1D 4444:0:0:4001::/64 [90/2684416] via FE80::3, Serial0/0/1

Verify

R1# ping 4444:0:0:4001::1

Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 4444:0:0:4001::1, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/60 msR1#

Default Route (one method)

R3(config)# inter ser 0/0/0R3(config-if)# ipv6 summary-address eigrp 100 ::/0

R3(config)# inter ser 0/0/1R3(config-if)# ipv6 summary-address eigrp 100 ::/0

R3(config)# ipv6 route ::/0 ser 0/1/0R3(config)# ipv6 route ::/0 ser 0/1/1

R3# show ipv6 route

S ::/0 [1/0] via ::, Serial0/1/0 via ::, Serial0/1/1<output omitted>

Propagate an EIGRP ::/0 summary route to R1 and R2

Create the default static route

Verify static route

Verify Static RouteR1# show ipv6 route

D ::/0 [90/2172416] via FE80::3, Serial0/0/1C 2340:1111:AAAA:101::/64 [0/0] via ::, FastEthernet0/0L 2340:1111:AAAA:101::1/128 [0/0] via ::, FastEthernet0/0D 2340:1111:AAAA:102::/64 [90/2172416] via FE80::2, Serial0/0/0<output omitted>

R1# ping 4444::1

Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 4444::1, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 56/56/56 msR1#

Time for Lab