1. IPv6 Routing IPv6 Workshop Manchester September 2013
Kateel Vijayananda
Wim Verrydt 1

2. Overview
OSPFv3
IS-IS
MP-BGP
Agenda

3. Each IPv4 Routing Protocol has an IPv6 Equivalent
RIPv2
RIPng
OSPFv2
OSPFv3
IS-IS
IS-IS for IPv6
EIGRP
EIGRP for IPv6
BGP
MP-BGP

4. Overview
OSPFv3
IS-IS
MP-BGP
Agenda

5. OSPFv3 vs OSPFv2 – Similarities are…
Defined in RFC 5340 – OSPF for IPv6
Runs directly over IPv6 (Extension Header 89)
Neighbor discovery and adjacency formation mechanisms are identical
All OSPF Routers FF02::5, All OSPF DRs FF02::6
LSA flooding and aging mechanisms are identical
Same interface types
P2P, P2MP, Broadcast, NBMA, Virtual
Independent process from OSPFv2

6. OSPFv3 vs OSPFv2 – Differences are…
Removal of Addressing Semantics Per Link Processing Instance ID LS Type in LSA Header is 16 bits in IPv6 (8 bits in IPv4) Explicit Flooding Scopes Explicit Unknown LSA Handling Adjacency formed over the Link-local address Authentication changes

7. OSPFv3 vs OSPFv2 – Differences are…
New Link-LSA
LSA 8
Announces IPv6 LLA to routers on the link
Announces IPv6 prefixes associated with the link
Generated for every link with 2 or more routers
New Intra-Area-Prefix LSA
LSA 9
Associates list of IPv6 Prefixes with network or router

8. OSPFv3 – Flooding Scope
Each LSA now contains two bits indicating the flooding scope
AS scope, LSA is flooded throughout the AS
Area scope, LSA is flooded only within an area
Link-local scope, LSA is flooded only on the local link
Indicated by “S bit” is LSA Link State Type Field S2 S1
Flooding Scope
Link-Local 1
Area
AS (Routing Domain)
Reserved
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9. OSPFv3 – Flooding Scope – Cntd.
These changes also impact the names of the LSAs
Type 3 (Summary LSA) = the Inter-area-prefix- LSA
Type 4 (Autonomous System Border LSA) = the Inter-area-router-LSA
Other new LSAs have been added (Link-LSA, Intra- area-prefix-LSA)

10. OSPFv3 LSA Types LS Type Name 0x2001 Router LSA 0x2002 Network LSA
Inter-Area Prefix LSA
0x2004
Inter-Area Router LSA
0x4005
AS-External LSA
0x2006
Group Membership LSA
0x2007
Type-7 LSA
0x0008
Link LSA
0x2009
Intra-Area Prefix LSA

11. Configuring OSPFv3 OSPFv3 process 2 on a LAN router with a Router-ID
Includes loopback, LAN and backbone interface !
ipv6 unicast-routing
ipv6 router ospfv3 2
router-id 10.<x>.0.1
interface Loopback0
ipv6 address 2001:DB8:<x>:<x>::1/128
ipv6 ospf 2 area <x>
interface Vlan <100+x>
ipv6 address 2001:DB8:<x>:CAFE::/64 eui-64
interface <backbone interface>
ipv6 address 2001:DB8:<x>:102::<x>/127

12. OSPFv3 – Show Example Router2#sh ipv6 route
IPv6 Routing Table - 5 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
O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1,
OE2 - OSPF ext 2
OI 2001:410:FFFF:1::/64 [110/2]
via FE80::2D0:FFFF:FE60:DFFF, POS3/0
C :B00:FFFF:1::/64 [0/0]
via ::, POS3/0
L :B00:FFFF:1::1/128 [0/0]
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
Area 1
Router 2
POS 3/0 2001:b00:ffff:1::1/64
2001:b00:ffff:1::2/64 POS 2/0
Router 1
POS 1/1 2001:410:ffff:1::1/64
Area 0
© 2009, Cisco Systems, Inc. All rights reserved.
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13. Overview
OSPFv3
IS-IS
MP-BGP
Agenda

14. IS-IS/IPv6 – Protocol Changes
RFC 5308 – Routing IPv6 with IS-IS
Originally routing only CLNP, then IPv4, now IPv6
Operationally similar to IS-ISv4
A new Network Layer Protocol Identifier (NLPID) is defined
Advertise IPv6 prefix payload using 0x8E value
New address family added
Neighbors listed in the Adjacency table with their LLA
Same protocol iteration can route both IPv4 and IPv6
© 2009, Cisco Systems, Inc. All rights reserved.
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15. IS-IS/IPv6 – New TLVs
Two type/length/values added to introduce IPv6 routing
IPv6 reachability TLV (0xEC)
IPv6 routing prefix, metric information and some option bits.
Equivalent to IP Internal/external reachability TLVs (RFC 1195)
IPv6 interface address TLV (0xE8)
Contains 128-bit address
Hello PDUs contain the link-local address (FE80::/10)
LSP only contain the non-link-local address

16. IS-IS/IPv6 – Single versus Multi-Topology
Single Topology
The IPv4 and IPv6 topologies must match
One SPF is run; IPv4 and IPv6 are mixed on the resulting SPT
Usually deployed
Multi-topology
Uses a different address family for IPv6 destinations
IPv4 and IPv6 topologies do not need to match
Useful for deployment where Dual Stack can not enabled everywhere
Multi-Topology_Reachable_IPv6_Prefixes TLV
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17. IS-IS for IPv6 – Configure Single- and Multi-Topology!
ipv6 unicast-routing
router isis
net c.00
interface GigabitEthernet0/0/1
ipv6 address 2001:DB8::3/64
ipv6 router isis !
ipv6 unicast-routing
router isis
metric-style wide
net c.00
address-family ipv6
multi-topology
exit-address-family
interface GigabitEthernet0/0/1
ipv6 router isis
isis ipv6 metric 20
Implementing IS-IS for IPv6

18. Overview
OSPFv3
IS-IS
MP-BGP
Agenda

19. MP-BGP Basics Path Vector Protocol
Peering
AS 301
Path Vector Protocol
Carries sequence of AS numbers indicating path
Ties Autonomous Systems together via Peering (EGP)
Multiple address families: IPv4, IPv6, unicast, multicast, VPNv4, VPNv6
Multi-Protocol Extension for IPv6 in RFC 2545

20. MP-BGP-4 Extensions
BGP-4 carries only 3 pieces of information which are truly IPv4 specific:
NLRI in the UPDATE message contains an IPv4 prefix
NEXT_HOP path attribute in the UPDATE message contains a IPv4 address
BGP Identifier in the OPEN message & AGGREGATOR attribute
Multi-Protocol Extensions in RFC 4760 (2238, 2858)
Enables BGP-4 to carry information of other protocols e.g MPLS, IPv6
Protocol independent NEXT_HOP attribute
Protocol independent NLRI attribute
New BGP-4 optional and non-transitive attributes:
MP_REACH_NLRI
MP_UNREACH_NLRI
To associate NLP with NH and NLRI => AFI + SAFI

21. MP-BGP-4 Extensions for IPv6
Address Family Information (AFI) for IPv6
AFI = 2
Sub-AFI = 1 Unicast
Sub-AFI = 2 (Multicast for RPF check)
Sub-AFI = 3 for both Unicast and Multicast
Sub-AFI = 4 Label
Sub-AFI = 128 VPN
TCP Interaction
BGP-4 runs on top of TCP
This connection could be setup either over IPv4 or IPv6
Router ID
When no IPv4 is configured, an explicit BGP router-id needs to be configured
Needed as a BGP Identifier, used as a tie breaker, and is send within the OPEN message

22. MP-BGP – Configure IPv6 Implementing Multiprotocol BGP for IPv6!
ipv6 unicast-routing
router bgp 65000
no bgp default ipv4-unicast
bgp router-id
neighbor 2001:DB8:0:CC00::1 remote-as 64600
address-family ipv6 unicast
neighbor 2001:DB8:0:CC00::1 activate
network 2001:DB8::/32
exit-address-family
Implementing Multiprotocol BGP for IPv6