© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v IPv6-Enabled Routing Protocols Examining Integrated IS/IS

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v Integrated IS-IS Characteristics Integrated IS-IS characteristics: IGP Link-state routing protocol Supports multiple network protocols at the same time Uses the same SPF for all network protocols

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v Integrated IS-IS for IPv6 Two TLVs added to introduce IPv6 routing: IPv6 reachability TLV (0xEC or 236) IPv6 interface address TLV (0xE8 or 232) New protocol identifier: IPv6 NLPID (0x8E or 142) advertised by IPv6-enabled routers

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v Single SPF Restrictions A single SPF runs per-level for OSI, IPv4, and IPv6. All routers in an area must run the same set of protocols (IPv4-only, IPv6-only, IPv4-IPv6). IPv4-IPv6 Router IPv4-Only Router OK Area NO Area OK Area

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v Single SPF Restrictions (Cont.) A single SPF runs per-level for OSI, IPv4, and IPv6. Layer 2 routers may be configured differently, but no routing hole must exist. IPv4-IPv6 Router IPv4-Only Router Area C Area B NO Area A L2 Area C Area B OK Area A L2

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v Multitopology IS-IS for IPv6 Separate SPF for IPv4 and IPv6: Removes some limitations to network design when running IS-IS for both IPv4 and IPv6 Available today

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v Configuring IS-IS IPv6 on Cisco Routers Use these steps to configure IS-IS IPv6 support: 1. Configure generic IS-IS interface attributes. 2. Configure IS-IS on IPv6 interfaces. 3. Configure IS-IS router mode attributes. 4. Configure IS-IS IPv6-specific attributes.

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v Cisco IOS IS-IS IPv6 Interface Commands Enable IS-IS IPv6 on an interface. [no] ipv6 router isis [ ] router(config-if)#

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v [no] address-family ipv6 router(config-router)# Enters IPv6 address family configuration mode [no] distance router(config-router-af)# Sets IS-IS IPv6 administrative distance [no] maximum-paths router(config-router-af)# Sets maximum number of paths [no] default-information originate [route-map ] router(config-router-af)# Configures origination of IPv6 default route Cisco IOS IS-IS IPv6 Address Family Commands

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v [no] adjacency-check router(config-router-af)# Enables or disables IPv6 adjacency checks Cisco IOS IS-IS IPv6 Adjacency Check Adjacency Check (default) IPv6 IPv4-IPv6IPv4 IPv4-IPv6 IPv6IPv4 No Adjacency Check IPv6 IPv4-IPv6IPv4 IPv4-IPv6 IPv6IPv4

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v show ipv6 protocols [summary] router# Displays the IS-IS IPv6 configuration debug isis adj-packets router# Debugs adjacency-related packets debug isis update-packets router# Debugs update-related packets show isis database show isis topology Cisco IOS IS-IS IPv6 show and debug Commands

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v Area IPv6-Only Configuration Redistributing IPv6 Static Routes RouterD# … interface FastEthernet0/0 ipv6 address 2001:db8:ffff::d/64 ipv6 router isis isis circuit-type level-2-only router isis address-family ipv6 redistribute static default-information originate exit-address-family net Area Cisco IOS IS-IS for IPv6-Only Configuration Example FastEthernet0/0 LAN1: 2001:db8:ffff::/64 RouterD RouterC

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v RouterC# … interface FastEthernet0/0 ipv6 address 2001:db8:ffff::c/64 ipv6 router isis isis circuit-type level-2-only interface FastEthernet0/1 ipv6 address 2001:db8:ffff:1::a/64 ipv6 router isis router isis address-family ipv6 redistribute static exit-address-family net RouterC Cisco IOS IS-IS for IPv6-Only Configuration Example (Cont.) Area IPv6-Only Configuration Redistributing IPv6 Static Routes Area LAN1: 2001:db8:ffff::/64 FastEthernet0/0 RouterD RouterC FastEthernet0/1 LAN2: 2001:db8:ffff:1:/64

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v RouterC# show ipv6 route is-is IPv6 Routing Table - 9 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 I2 ::/0 [115/10] via FE80::208:A3FF:FEAE:64A0, FastEthernet0/0 Cisco IOS IS-IS show Command Example Area Area LAN1: 2001:db8:ffff::/64 FastEthernet0/0 RouterD RouterC FastEthernet0/1 LAN2: 2001:db8:ffff:1:/64

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v RouterC IPv6 IPv6 over GRE IPv4 Tunnel Configuration GRE tunnel type is required for IS-IS. Tunnel0 Cisco IOS IS-IS for IPv6 over IPv4 Tunnel Configuration Example RouterD IPv6 IPv4 RouterD# … interface Tunnel0 ipv6 address 2001:DB8:ffff::d/64 tunnel source Ethernet0 tunnel destination ipv6 router isis tunnel mode gre ipv6 router isis net address-family ipv6 ….

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v Summary IS-IS for IPv6 remains a link-state routing protocol and supports multiple network protocols at the same time. IS-IS for IPv6 introduces two new TLVs to support IPv6 prefixes and a new protocol identifier. When running IS-IS for IPv6 in a single SPF, all routers must support the same set of network protocols. Multitopology IS-IS allows multiple network protocols to be enabled in a single SPF. IPv6-specific IS-IS commands are entered under the address- family configuration mode on Cisco routers.

© 2006 Cisco Systems, Inc. All rights reserved. IP6FD v