ipv6 routing protocols
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Cisco Confidential 1Cisco Confidential 1Cisco Confidential 1Cisco Confidential© 2011 Cisco and/or its affiliates. All rights reserved. 1
• Overview• Overview
• Static Routing
• Dynamic Routing
• RIPng
• EIGRP for IPv6
• OSPFv3
© 2011 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 2
• OSPFv3
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• Main motivation for IPv6 is lack of IPv4 address space
• IPv4 uses 32-bits
2^32 = 4,294,967,296 max addresses
• IPv6 uses 128-bits
2^128 = 34,028,236,6 92,938,463,463,374,607,431,770,000,000+
© 2011 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 4
• IPv4 Dotted Decimal
1.2.3.4
Each place denotes 1 byteEach place denotes 1 byte
• IPv6 Hexadecimal
XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX
Two characters = one byte
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• 2.4 Address Type Representation
• The specific type of an IPv6 address is indicated by the leading bits in the address. The variable-length field comprising these leading bits is called the Format Prefix (FP). The initial allocation of these prefixes is as follows:these prefixes is as follows:
• Allocation Prefix Fraction of (binary) Address Space
• ----------------------------------- -------- -------------
• Aggregatable Global Unicast Addresses 001 1/8
• Link-Local Unicast Addresses 1111 1110 10 1/1024
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• Link-Local Unicast Addresses 1111 1110 10 1/1024
• Site-Local Unicast Addresses 1111 1110 11 1/1024
• Multicast Addresses 1111 1111 1/256
• • Four main address types
• Global Unicast
�2000… – 3FFF…�2000… – 3FFF…
• Unique Local
�FC00…
Deprecates Site Local (FEC0)
• Link Local
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• Link Local
�FE80…
• Multicast
�FF…
• IPv6 host addresses are generated from interface MAC address
• MAC address is 48-bits
• IPv6 host address is 64-bits• IPv6 host address is 64-bits
• Extra 16 bits derived as follows:
MAC 1234.5678.9012
Invert 7th most significant bit
12 = 0001 0010
0001 0000
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0001 0000
1034.5678.9012
• Insert “FFFE” in middle
1034:56FF:FE78:9012
• ICMPv6 ND
� Replaces IPv4 ARP
• NS – Neighbor Solicitation• NS – Neighbor Solicitation
� Ask for information about neighbor
• NA – Neighbor Advertisement
� Advertise yourself to other neighbors
• RS – Router Solicitation
� Ask for information about local routers
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� Ask for information about local routers
• RA – Router Advertisement
� Advertise yourself as an active router
• IPv6 unicast routing off by default
� ipv6 unicast-routing
• Dynamic routing through• Dynamic routing through
� RIPng
� OSPFv3
� EIGRPv6
� IS-IS
� BGP
• • Dynamic information recurses to remote linklocal address
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• • Dynamic information recurses to remote linklocal address
Layer 3 to layer 2 resolution on multipoint NBMA medias
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• Similar to IPv4
• Next hop / interface is required Static routing CLI for IPv6
ipv6 route ipv6-prefix/prefix-length {ipv6-address | interface-type interface-number [ipv6-address]}
[administrative-distance] [administrative-multicast-distance | unicast | multicast] [tag tag]
!
Router(config)# ipv6 route 2001:DB8::0/32 2001:DB8:1:1::1 10
!
Router(config)# ipv6 route 2001:DB8::/32 Ethernet 1/0 FE80::215:C7FF:FE21:8640
!
Forward a packets via GUA NH using admin of 10
Forward a packets via link-local NH
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LAN1: 2001:db8:c18:1::/64
Ethernet0
Router 2
IPv6 Internet
:a
:e
router 1#config termipv6 unicast-routing!interface Ethernet0
LAN2: 2001:db8:c18:2::/64
Ethernet1
Router 1
:a
:a
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interface Ethernet0ipv6 address 2001:db8:c18:1::a/64 !interface Ethernet1ipv6 address 2001:db8:c18:2::a/64!ipv6 route ::/0 2001:db8:c18:1::e
Default router to Router 2
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• Routing in IPv6 is unchanged from IPv4
Still has two families of routing protocols: IGP and EGP
Still uses the longest-prefix match routing algorithm
• IGP
RIPng (RFC 2080)
Cisco EIGRP for IPv6
Integrated IS-IS for IPv6 (RFC 5308)
OSPFv3 (RFC 5340)
• EGP
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MP-BGP4 (RFC 4760) and Using MP-BGP for IPv6 (RFC 2545)
• Cisco IOS supports all IPv6 routing protocols
• Dynamic routing protocols require a router-id
Router-id is a 32 bit integer in dotted decimal notation (a.b.c.d)
Auto-generated from IPv4 loopback interface address if configured,
Otherwise highest IPv4 address on the routerOtherwise highest IPv4 address on the router
Many networks will deploy IPv6 dual stack – so router-id will be automatically created
• For IPv6 only networks where no IPv4 address is available
Router-id needs to be manually configured using dotted decimal notation (looks like an IPv4 address)
ipv6 router ospf 100
router-id 10.1.1.4
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• Referred to as RIP Next Generation, distance vector protocol
• For the SP industry not recommended, limited use in Enterprise environments
• ISPs do not use RIP in any form unless there is absolutely no alternative• ISPs do not use RIP in any form unless there is absolutely no alternative
• RIPng was used in the early days of the IPv6 test network
Superior routing protocols such as ISIS, OSPF and BGP rapidly replaced RIPng
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• Similar to RIPv2
Distance-vector, Hop limit of 15, split-horizon, All RIP routers is FF02::9, UDP port (521)
• Updated features for IPv6
Prefix length added, address-family and subnet mask fields removed
Field’s Name kept from IPv4 to IPv6
Fields not kept in IPv6
Name and/or position changed in IPv6
New Field in IPv6
Leg
en
d
Command Version Set to zero
Address Family ID Route Tag
Command Version Set to zero
IPv6 Next Hop
0 0 0xFF
Prefix length added, address-family and subnet mask fields removed
• Special Handling for the NH
One NH entry per group of prefixes
RIP header
RIPng header
Routing Table Entry (RTE)for next hop
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Address Family ID Route Tag
IPv4 Prefix
Subnet Mask
Next Hop
Metric
0 0 0xFF
IPv6 prefix
Route Tag Prefix Len Metric
Routing Table Entry (RTE)for prefixes (1 .. N) sharing same next hop
Router2#config term
LAN1: 2001:db8:c18:1::/64
Ethernet0
Router 2
2001:db8:c18:1:260:3eff:fe47:1530
::/0
Ethernet0
Default route from R2
Router2#config term
ipv6 router rip RT0
interface Ethernet0
ipv6 address 2001:db8:c18:1::/64 eui-64
ipv6 rip RT0 enable
ipv6 rip RT0 default-information originate
LAN2: 2001:db8:c18:2::/64
Ethernet0
Ethernet1
Router 1
Router2# debug ipv6 rip
Router1#config term
ipv6 router rip RT0
!
interface Ethernet0 Show RIP update
Enable RIP routing
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Router2# debug ipv6 rip
RIPng: Sending multicast update on Ethernet0 for RT0
src=FE80::260:3eff:fe47:1530
dst=FF02::9 (Ethernet0)
sport=521, dport=521, length=32
command=2, version=1, mbz=0, #rte=1
tag=0, metric=1, prefix=::/0
interface Ethernet0
ipv6 address 2001:db8:c18:1::/64 eui-64
ipv6 rip RT0 enable
!
interface Ethernet1
ipv6 address 2001:db8:c18:2::/64 eui-64
ipv6 rip RT0 enable
Show RIP update
Use link-local as source
Destination is All RIPng routers
R1# show ipv6 routeIPv6 Routing Table - 10 entriesCodes: C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static routeI1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summaryO - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2D - EIGRP, EX - EIGRP external
C 2001:DB8:1::/64 [0/0]via ::, Loopback1
L 2001:DB8:1:0:A8BB:CCFF:FE00:100/128 [0/0]via ::, Loopback1
R 2001:DB8:2::/64 [120/2]via FE80::A8BB:CCFF:FE00:200, Serial2/0
R 2001:DB8:3::/64 [120/3]via FE80::A8BB:CCFF:FE00:200, Serial2/0
C 2001:DB8:12::/64 [0/0]via ::, Serial2/0
L 2001:DB8:12:0:A8BB:CCFF:FE00:100/128 [0/0]
Note all RIP next hops are link-local addresses (FE80::)
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L 2001:DB8:12:0:A8BB:CCFF:FE00:100/128 [0/0]via ::, Serial2/0
R 2001:DB8:23::/64 [120/2]via FE80::A8BB:CCFF:FE00:200, Serial2/0
L FF00::/8 [0/0]via ::, Null0
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• Three new TLVs:
0X0401 - Internal Prefix
0X0402 - External Prefix
0X0403 - Unused0X0403 - Unused
• Hello messages use the link-local address as the src and dst of FF02::A (all EIGRProuters).
Neighbors do not have to share the same global prefix (with the exception of explicitly specified neighbors)
• Automatic summarization is disabled by default for IPv6 (unlike IPv4)
• Support for “no split-horizon” in the case of NBMA links
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• Support for “no split-horizon” in the case of NBMA links
For example, multi-point GRE as found in DMVPN deployments, or ATM/Frame services
• RID stays at 32 bits
• Expected to be very popular amongst existing enterprise networks
Router2#config termipv6 router eigrp 100eigrp router-id 10.10.10.1
LAN1: 2001:db8:c18:1::/64
Ethernet0
Router 2 2001:db8:c18:1:260:3eff:fe47:1530
Ethernet0
interface Ethernet0ipv6 address 2001:db8:c18:1::/64 eui-64ipv6 eigrp 100
LAN2: 2001:db8:c18:2::/64
Ethernet1
Router 1
Router1# show ipv6 eigrp neighborIPv6-EIGRP neighbors for process 100H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num Neighbors and next hops are identified by link-local address
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(ms) Cnt Num0 FE80::260:3eff:fe47:1530 E0 14 00:01:43 1 4500 0 1
Router1# show ipv6 eigrp topology all-linksIPv6-EIGRP Topology Table for AS(100)/ID(10.10.10.1)Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia StatusP 2001:db8:c18:1::/64, 1 successors, FD is 28160, serno 1
via Connected, Ethernet0via FE80::260:3eff:fe47:1530 (30720/28160), Ethernet0
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• OSPFv3 is OSPF for IPv6 (RFC 5340)
• Based on OSPFv2 with enhancements
• Distributes IPv6 prefixes only• Distributes IPv6 prefixes only
• Runs directly over IPv6
• Ships-in-the-night with OSPFv2
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• OSPFv3 has same 5 packet types some fields have been changed
• OSPFv3 packets have a 16 byte header verses the 24 byte header in OSPFv2
Packet Type Description
1 Hello1 Hello
2 Database description
3 Link state request
4 Link state update
5 Link state acknowledgement
Version Type Packet Length
Router ID
Field’s Name kept from IPv4 to IPv6
Fields not kept in IPv6
Name and/or position changed in IPv6
New Field in IPv6
Leg
en
d
Version Type Packet Length
Router ID
OSPFv3OSPFv2
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Router ID
Area ID
Checksum Authtype
Authentication
Authentication
Router ID
Area ID
ChecksumInstance
ID0
• Uses link local addresses
To identify the OSPFv3 adjacency neighbors
• Two New LSA Types
Link-LSA (LSA Type 0x0008)
There is one Link-LSA per link. This LSA advertises the router's link-local address, list of all IPv6 prefixes and options associated with the link to all other routers attached to the link
Intra-Area-Prefix-LSA (LSA Type 0x2009)
Carries all IPv6 prefix information that in IPv4 is included in Router-LSAs and Network-LSAs
• Two LSAs are renamed
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• Two LSAs are renamed
Type-3 summary-LSAs, renamed to “Inter-Area-Prefix-LSAs”
Type-4 summary LSAs, renamed to “Inter-Area-Router-LSAs”
• Multicast Addresses
FF02::5 – Represents all SPF routers on the link local scope, Equivalent to 224.0.0.5 in OSPFv2
FF02::6 – Represents all DR routers on the link local scope, Equivalent to 224.0.0.6 in OSPFv2
• Removal of Address Semantics
IPv6 addresses are no longer present in OSPF packet header (Part of payload information)
Router LSA, Network LSA do not carry IPv6 addresses
Router ID, Area ID and Link State ID remains at 32 bits
DR and BDR are now identified by their Router ID and no longer by their IP address
• Security
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OSPFv3 uses IPv6 AH & ESP extension headers instead of variety of mechanisms defined in OSPFv2
LSA Description LSA Code LSA Type Bits Set=1
Router LSA 1 0x2001 S1
Network LSA 2 0x2002 S1
Inter-Area-Prefix-LSA 3 0x2003 S1
U Bit LSA Handling
0 Treat the LSA as if it had link-local flooding scope
1 Store and flood the LSA as if the type is understood
Inter-Area-Prefix-LSA 3 0x2003 S1
Inter-Area-Router-LSA 4 0x2004 S1
AS-External-LSA 5 0x4005 S2
Deprecated 6 0x2006 S1
NSSA-LSA 7 0x2007 S1
Link-LSA 8 0x0008
Intra-Area-Prefix-LSA 9 0x2009 S1
S2 S1 Flooding Scope
0 0 Link-Local Scoping - Flooded only on originating link
0 1 Area Scoping - Flooded only in originating area
1 0 AS Scoping - Flooded throughout AS
1 1 Reserved
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Intra-Area-Prefix-LSA 9 0x2009 S1
U S2 S1 LSA Function Code
1Bit 1Bit 1Bit 13 Bits
LSA Type Format
Router1#interface POS1/1ipv6 address 2001:410:FFFF:1::1/64ipv6 ospf 100 area 0! interface POS2/0ipv6 address 2001:db8:FFFF:1::2/64Router 2
Area 1Enables IPv6 facing Area 0
Interlink connection (could use link-local)
POS3/0 2001:db8:ffff:1::1/64
POS1/1
Router 1
ipv6 address 2001:db8:FFFF:1::2/64ipv6 ospf 100 area 0! ipv6 router ospf 100
router-id 10.1.1.3
Router2#interface POS3/0ipv6 address 2001:db8:FFFF:1::1/64ipv6 ospf 100 area 0! ipv6 router ospf 100
router-id 10.1.1.4
Router 2
POS 2/0 2001:db8:ffff:1::2/64
Area 032 bit ID specified in dotted decimal notation
Interlink connection (could use link-local)
Interlink connection (could use link-local)
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2001:410:ffff:1::1/64
router-id 10.1.1.4Area 032 bit ID specified in dotted decimal notation
Router1#interface POS1/1ipv6 address 2001:410:FFFF:1::1/64ospfv3 100 area 0 ipv6! interface POS2/0ipv6 address 2001:db8:FFFF:1::2/64Router 2
Area 1Enables IPv6 facing Area 0
Interlink connection (could use link-local)
POS3/0 2001:db8:ffff:1::1/64
POS1/1
Router 1
ipv6 address 2001:db8:FFFF:1::2/64ospfv3 100 area 1 ipv6! router ospfv3 100
router-id 10.1.1.3
Router2#interface POS3/0ipv6 address 2001:db8:FFFF:1::1/64ospfv3 100 area 1 ipv6! router ospfv3 100
router-id 10.1.1.4
Router 2
POS 2/0 2001:db8:ffff:1::2/64
Area 032 bit ID specified in dotted decimal notation
Interlink connection (could use link-local)
Interlink connection (could use link-local)
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2001:410:ffff:1::1/64
router-id 10.1.1.4Area 032 bit ID specified in dotted decimal notation
Supported as of 15T/15S IOS trains
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