Configuring IPv6 IS-IS· 1

Introduction to IPv6 IS-IS· 1

Configuring IPv6 IS-IS basic functions 1

Configuration prerequisites 1

Configuration procedure· 1

Configuring IPv6 IS-IS routing information control 2

Configuration prerequisites 2

Configuration procedure· 2

Configuring BFD for IPv6 IS-IS· 3

Displaying and maintaining IPv6 IS-IS· 4

IPv6 IS-IS configuration examples 5

IPv6 IS-IS basic configuration example· 5

Configuring BFD for IS-IS· 8

 

 

NOTE: ·       IPv6 IS-IS supports all IPv4 IS-IS features, but advertises IPv6 routing information. This document describes only IPv6 IS-IS exclusive configuration tasks. For other configuration tasks, see the chapter “Configuring IS-IS.” ·       The term router in this document refers to both routers and Layer 3 switches.

 

Introduction to IPv6 IS-IS

The IS-IS routing protocol (Intermediate System-to-Intermediate System intra-domain routing information exchange protocol) supports multiple network protocols, including IPv6. The international engineer task force (IETF) defines two type-length-values (TLVs) and a new network layer protocol identifier (NLPID) to enable IS-IS to support IPv6.

TLV is a variable-length field in the link state PDU or link state packet (LSP). The two TLVs are:

·           IPv6 Reachability—Defines the prefix, metric of routing information to indicate network reachability, and has a type value of 236 (0xEC).

·           IPv6 Interface Address—Same as the “IP Interface Address” TLV in IPv4 ISIS, except that the 32-bit IPv4 address is translated to the 128-bit IPv6 address.

The NLPID is an 8-bit field that identifies which network layer protocol is supported. For IPv6, the NLPID is 142 (0x8E), which must be carried in hello packets sent by a router that supports IPv6 IS-IS.

For information about IS-IS, see the chapter “Configuring IS-IS.”

Configuring IPv6 IS-IS basic functions

 

NOTE: You can implement IPv6 inter-networking through configuring IPv6 IS-IS in IPv6 network environment.

 

Configuration prerequisites

Before the configuration, complete the following tasks:

·           Enable IPv6 globally.

·           Configure IP addresses for interfaces, and make sure that all neighboring nodes are reachable to each other.

·           Enable IS-IS.

Configuration procedure

To configure the basic functions of IPv6 IS-IS:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enable an IS-IS process and enter IS-IS view.	isis [ process-id ] [ vpn-instance vpn-instance-name ]	Not enabled by default
3.     Configure the network entity title for the IS-IS process.	network-entity net	Not configured by default
4.     Enable IPv6 for the IS-IS process.	ipv6 enable	Disabled by default
5.     Return to system view.	quit	N/A
6.     Enter interface view.	interface interface-type interface-number	N/A
7.     Enable IPv6 for an IS-IS process on the interface.	isis ipv6 enable [ process-id ]	Disabled by default

 

Configuring IPv6 IS-IS routing information control

Configuration prerequisites

Complete the IPv6 IS-IS basic function configuration before configuring this task.

Configuration procedure

To configure IPv6 IS-IS routing information control:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter IS-IS view.	isis [ process-id ] [ vpn-instance vpn-instance-name ]	N/A
3.     Define the priority for IPv6 IS-IS routes.	ipv6 preference { route-policy route-policy-name | preference } *	Optional. 15 by default.
4.     Configure an IPv6 IS-IS summary route.	ipv6 summary ipv6-prefix prefix-length [ avoid-feedback | generate_null0_route | [ level-1 | level-1-2 | level-2 ] | tag tag ] *	Optional. Not configured by default.
5.     Generate an IPv6 IS-IS default route.	ipv6 default-route-advertise [ [ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name ] *	Optional. By default, no IPv6 default route is defined.
6.     Configure IPv6 IS-IS to filter incoming routes.	ipv6 filter-policy { acl6-number | ipv6-prefix ipv6-prefix-name | route-policy route-policy-name } import	Optional. No filtering policy is defined by default.
7.     Configure IPv6 IS-IS to redistribute routes from another routing protocol.	ipv6 import-route protocol [ process-id ] [ allow-ibgp ] [ cost cost | [ level-1 | level-1-2 | level-2 ] | route-policy route-policy-name | tag tag ] *	Optional. Not configured by default.
8.     Configure the maximum number of redistributed Level 1/Level 2 IPv6 routes.	ipv6 import-route limit number	Optional.
9.     Configure the filtering of outgoing redistributed routes.	ipv6 filter-policy { acl6-number | ipv6-prefix ipv6-prefix-name | route-policy route-policy-name } export [ protocol [ process-id ] ]	Optional. Not configured by default.
10.   Enable route leaking.	ipv6 import-route isisv6 level-2 into level-1 [ filter-policy { acl6-number | ipv6-prefix ipv6-prefix-name | route-policy route-policy-name } | tag tag ] *	Optional. Not enabled by default.
11.   Specify the maximum number of equal-cost load balanced routes.	ipv6 maximum load-balancing number	Optional. By default, load balancing is disabled.

 

NOTE: ·       The ipv6 filter-policy export command is usually used in combination with the ipv6 import-route command. If no protocol is specified for the ipv6 filter-policy export command, routes redistributed from all routing protocols are filtered before advertisement. If a protocol is specified, only routes redistributed from the routing protocol are filtered for advertisement. ·       For information about ACL, see ACL and QoS Configuration Guide. ·       For information about routing policy and IPv6 prefix list, see the chapter “Configuring routing policies.”

 

Configuring BFD for IPv6 IS-IS

Bidirectional forwarding detection (BFD) provides a mechanism to quickly detect the connectivity of links between IPv6 IS-IS neighbors, thus to improve the convergence speed of IPv6 IS-IS.

To configure BFD for IPv6 IS-IS:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enable an IS-IS process and enter IS-IS view.	isis [ process-id ]	N/A
3.     Configure the network entity title for the IS-IS process.	network-entity net	Not configured by default
4.     Enable IPv6 for the IS-IS process.	ipv6 enable	Disabled by default
5.     Return to system view.	quit	N/A
6.     Enter interface view.	interface interface-type interface-number	N/A
7.     Enable IPv6 for an IS-IS process on the interface.	isis ipv6 enable [ process-id ]	Disabled by default
8.     Enable BFD on the interface.	isis ipv6 bfd enable	Not enabled by default

 

NOTE: For more information about BFD, see High Availability Configuration Guide.

 

Displaying and maintaining IPv6 IS-IS

 

Task	Command	Remarks
Display brief IPv6 IS-IS information.	display isis brief [ | { begin | exclude | include } regular-expression ]	Available in any view
Display the status of the debug switches.	display isis debug-switches { process-id | vpn-instance vpn-instance-name } [ | { begin | exclude | include } regular-expression ]	Available in any view
Display IS-IS enabled interface information.	display isis interface [ statistics | [ interface-type interface-number ] [ verbose ] ] [ process-id | vpn-instance vpn-instance-name ] [ | { begin | exclude | include } regular-expression ]	Available in any view
Display LSDB information.	display isis lsdb [ [ l1 | l2 | level-1 | level-2 ] | [ [ lsp-id lsp-id | lsp-name lspname | local ] | verbose ] * ] * [ process-id | vpn-instance vpn-instance-name ] [ | { begin | exclude | include } regular-expression ]	Available in any view
Display IS-IS mesh group information.	display isis mesh-group [ process-id | vpn-instance vpn-instance-name ] [ | { begin | exclude | include } regular-expression ]	Available in any view
Display the mapping table between the host name and system ID.	display isis name-table [ process-id | vpn-instance vpn-instance-name ] [ | { begin | exclude | include } regular-expression ]	Available in any view
Display IS-IS neighbor information.	display isis peer [ statistics | verbose ] [ process-id | vpn-instance vpn-instance-name ] [ | { begin | exclude | include } regular-expression ]	Available in any view
Display IPv6 IS-IS routing information.	display isis route ipv6 [ [ level-1 | level-2 ] | verbose ] * [ process-id | vpn-instance vpn-instance-name ] [ | { begin | exclude | include } regular-expression ]	Available in any view
Display SPF log information.	display isis spf-log [ process-id | vpn-instance vpn-instance-name ] [ | { begin | exclude | include } regular-expression ]	Available in any view
Display the statistics of the IS-IS process.	display isis statistics [ level-1 | level-1-2 | level-2 ] [ process-id |  vpn-instance vpn-instance-name ] [ | { begin | exclude | include } regular-expression ]	Available in any view
Clear all IS-IS data structure information.	reset isis all [ process-id | vpn-instance vpn-instance-name ]	Available in user view
Clear the IS-IS data information of a neighbor.	reset isis peer system-id [ process-id | vpn vpn-instance-name ]	Available in user view

 

IPv6 IS-IS configuration examples

IPv6 IS-IS basic configuration example

Network requirements

As shown in Figure 1, Router A, Router B, Router C and Router D, all enabled with IPv6, reside in the same autonomous system. Configure IPv6 IS-IS on the routers to make them reachable to each other.

Router A and Router B are Level-1 routers, Router D is a Level-2 router, and Router C is a Level-1-2 router. Router A, Router B, and Router C belong to area 10, and Router D is in area 20.

Figure 1 Network diagram

 

Configuration procedure

1.      Configure IPv6 addresses for interfaces. (Details not shown)

2.      Configure IPv6 IS-IS:

# Configure Router A.

<RouterA> system-view

[RouterA] isis 1

[RouterA-isis-1] is-level level-1

[RouterA-isis-1] network-entity 10.0000.0000.0001.00

[RouterA-isis-1] ipv6 enable

[RouterA-isis-1] quit

[RouterA] interface POS 2/1/1

[RouterA-POS2/1/1] isis ipv6 enable 1

[RouterA-POS2/1/1] quit

# Configure Router B.

<RouterB> system-view

[RouterB] isis 1

[RouterB-isis-1] is-level level-1

[RouterB-isis-1] network-entity 10.0000.0000.0002.00

[RouterB-isis-1] ipv6 enable

[RouterB-isis-1] quit

[RouterB] interface POS 2/1/1

[RouterB-POS2/1/1] isis ipv6 enable 1

[RouterB-POS2/1/1] quit

# Configure Router C.

<RouterC> system-view

[RouterC] isis 1

[RouterC-isis-1] network-entity 10.0000.0000.0003.00

[RouterC-isis-1] ipv6 enable

[RouterC-isis-1] quit

[RouterC] interface POS 2/1/1

[RouterC-POS2/1/1] isis ipv6 enable 1

[RouterC-POS2/1/1] quit

[RouterC] interface POS 2/1/2

[RouterC-POS2/1/2] isis ipv6 enable 1

[RouterC-POS2/1/2] quit

[RouterC] interface POS 2/1/3

[RouterC-POS2/1/3] isis ipv6 enable 1

[RouterC-POS2/1/3] quit

# Configure Router D.

<RouterD> system-view

[RouterD] isis 1

[RouterD-isis-1] is-level level-2

[RouterD-isis-1] network-entity 20.0000.0000.0004.00

[RouterD-isis-1] ipv6 enable

[RouterD-isis-1] quit

[RouterD] interface POS 2/1/1

[RouterD-POS2/1/1] isis ipv6 enable 1

[RouterD-POS2/1/1] quit

[RouterD] interface GigabitEthernet 1/1/1

[RouterD-GigabitEthernet1/1/1] isis ipv6 enable 1

[RouterD-GigabitEthernet1/1/1] quit

3.      Verify the configuration:

# Display the IPv6 IS-IS routing table of Router A.

[RouterA] display isis route ipv6

                         Route information for ISIS(1)

                         -----------------------------

                     ISIS(1) IPv6 Level-1 Forwarding Table

                     -------------------------------------

 Destination: ::                                      PrefixLen: 0

 Flag       : R/-/-                                   Cost     : 10

 Next Hop   : FE80::200:FF:FE0F:4                     Interface: S2/1/1

 Destination: 2001:1::                                PrefixLen: 64

 Flag       : D/L/-                                   Cost     : 10

 Next Hop   : Direct                                  Interface: S2/1/1

 Destination: 2001:2::                                PrefixLen: 64

 Flag       : R/-/-                                   Cost     : 20

 Next Hop   : FE80::200:FF:FE0F:4                     Interface: S2/1/1

 Destination: 2001:3::                                PrefixLen: 64

 Flag       : R/-/-                                   Cost     : 20

 Next Hop   : FE80::200:FF:FE0F:4                     Interface: S2/1/1

      Flags: D-Direct, R-Added to RM, L-Advertised in LSPs, U-Up/Down Bit Set

# Display the IPv6 IS-IS routing table of Router B.

[RouterB] display isis route ipv6

                         Route information for ISIS(1)

                         -----------------------------

                     ISIS(1) IPv6 Level-1 Forwarding Table

                     -------------------------------------

 Destination: ::                                      PrefixLen: 0

 Flag       : R/-/-                                   Cost     : 10

 Next Hop   : FE80::200:FF:FE0F:4                     Interface: S2/1/1

 Destination: 2001:1::                                PrefixLen: 64

 Flag       : D/L/-                                   Cost     : 10

 Next Hop   : FE80::200:FF:FE0F:4                     Interface: S2/1/1

 Destination: 2001:2::                                PrefixLen: 64

 Flag       : R/-/-                                   Cost     : 20

 Next Hop   : Direct                                  Interface: S2/1/1

 Destination: 2001:3::                                PrefixLen: 64

 Flag       : R/-/-                                   Cost     : 20

 Next Hop   : FE80::200:FF:FE0F:4                     Interface: S2/1/1

      Flags: D-Direct, R-Added to RM, L-Advertised in LSPs, U-Up/Down Bit Set

# Display the IPv6 IS-IS routing table of Router C.

[RouterC] display isis route ipv6

                         Route information for ISIS(1)

                         -----------------------------

                     ISIS(1) IPv6 Level-1 Forwarding Table

                     -------------------------------------

 Destination: 2001:1::                                PrefixLen: 64

 Flag       : D/L/-                                   Cost     : 10

 Next Hop   : Direct                                  Interface: S2/1/2

 Destination: 2001:2::                                PrefixLen: 64

 Flag       : D/L/-                                   Cost     : 10

 Next Hop   : Direct                                  Interface: S2/1/1

 Destination: 2001:3::                                PrefixLen: 64

 Flag       : D/L/-                                   Cost     : 10

 Next Hop   : Direct                                  Interface: S2/1/3

      Flags: D-Direct, R-Added to RM, L-Advertised in LSPs, U-Up/Down Bit Set

                     ISIS(1) IPv6 Level-2 Forwarding Table

                     -------------------------------------

 Destination: 2001:1::                                PrefixLen: 64

 Flag       : D/L/-                                   Cost     : 10

 Next Hop   : Direct                                  Interface: S2/1/2

 Destination: 2001:2::                                PrefixLen: 64

 Flag       : D/L/-                                   Cost     : 10

 Next Hop   : Direct                                  Interface: S2/1/1

 Destination: 2001:3::                                PrefixLen: 64

 Flag       : D/L/-                                   Cost     : 10

 Next Hop   : Direct                                  Interface: S2/1/3

 Destination: 2001:4::1                               PrefixLen: 128

 Flag       : R/-/-                                   Cost     : 10

 Next Hop   : FE80::20F:E2FF:FE3E:FA3D                Interface: S2/1/3

      Flags: D-Direct, R-Added to RM, L-Advertised in LSPs, U-Up/Down Bit Set

# Display the IPv6 IS-IS routing table of Router D.

[RouterD] display isis route ipv6

                         Route information for ISIS(1)

                         -----------------------------

                     ISIS(1) IPv6 Level-2 Forwarding Table

                     -------------------------------------

 Destination: 2001:1::                                PrefixLen: 64

 Flag       : R/-/-                                   Cost     : 20

 Next Hop   : FE80::200:FF:FE0F:4                     Interface: S2/1/1

Destination: 2001:2::                                PrefixLen: 64

 Flag       : R/-/-                                   Cost     : 20

 Next Hop   : FE80::200:FF:FE0F:4                     Interface: S2/1/1

 Destination: 2001:3::                                PrefixLen: 64

 Flag       : D/L/-                                   Cost     : 10

 Next Hop   : Direct                                  Interface: S2/1/1

 Destination: 2001:4::1                               PrefixLen: 128

 Flag       : D/L/-                                   Cost     : 0

 Next Hop   : Direct                                  Interface: GE1/1/1

      Flags: D-Direct, R-Added to RM, L-Advertised in LSPs, U-Up/Down Bit Set

Configuring BFD for IS-IS

Network requirements

·           As shown in Figure 2, configure IPv6 IS-IS on Router A, Router B and Router C and configure BFD over the link Router A<—>L2 Switch<—>Router B.

·           After the link between Router B and the Layer-2 switch fails, BFD can quickly detect the failure and notify IPv6 IS-IS of the failure. Then Router A and Router B communicate through Router C.

Figure 2 Network diagram

Device	Interface	IPv6 address	Device	Interface	IPv6 address
Router A	GE3/1/1	2001::1/64	Router B	GE3/1/1	2001::2/64
	GE3/1/2	2001:2::1/64		GE3/1/2	2001:3::2/64
Router C	GE3/1/1	2001:2::2/64
	GE3/1/2	2001:3::1/64

 

Configuration procedure

1.      Configure IP addresses for interfaces. (Details not shown)

2.      Configure IPv6 IS-IS:

# Configure Router A.

<RouterA> system-view

[RouterA] ipv6

[RouterA] isis 1

[RouterA-isis-1] is-level level-1

[RouterA-isis-1] network-entity 10.0000.0000.0001.00

[RouterA-isis-1] ipv6 enable

[RouterA-isis-1] quit

[RouterA] interface GigabitEthernet 3/1/1

[RouterA-GigabitEthernet3/1/1] isis ipv6 enable 1

[RouterA-GigabitEthernet3/1/1] quit

[RouterA] interface GigabitEthernet 3/1/2

[RouterA-GigabitEthernet3/1/2] isis ipv6 enable 1

[RouterA-GigabitEthernet3/1/2] quit

# Configure Router B.

<RouterB> system-view

[RouterA] ipv6

[RouterB] isis 1

[RouterB-isis-1] is-level level-1

[RouterB-isis-1] network-entity 10.0000.0000.0002.00

[RouterB-isis-1] ipv6 enable

[RouterB-isis-1] quit

[RouterB] interface GigabitEthernet 3/1/1

[RouterB-GigabitEthernet3/1/1] isis ipv6 enable 1

[RouterB-GigabitEthernet3/1/1] quit

[RouterB] interface GigabitEthernet 3/1/2

[RouterB-GigabitEthernet3/1/2] isis ipv6 enable 1

[RouterB-GigabitEthernet3/1/2] quit

# Configure Router C.

<RouterC> system-view

[RouterA] ipv6

[RouterC] isis 1

[RouterC-isis-1] network-entity 10.0000.0000.0003.00

[RouterC-isis-1] ipv6 enable

[RouterC-isis-1] quit

[RouterC] interface GigabitEthernet 3/1/1

[RouterC-GigabitEthernet3/1/1] isis ipv6 enable 1

[RouterC-GigabitEthernet3/1/1] quit

[RouterC] interface GigabitEthernet 3/1/2

[RouterC-GigabitEthernet3/1/2] isis ipv6 enable 1

[RouterC-GigabitEthernet3/1/2] quit

3.      Configure BFD functions:

# Enable BFD on Router A and configure BFD parameters.

[RouterA] bfd session init-mode active

[RouterA] interface GigabitEthernet 3/1/1

[RouterA-GigabitEthernet3/1/1] isis ipv6 bfd enable

[RouterA-GigabitEthernet3/1/1] bfd min-transmit-interval 500

[RouterA-GigabitEthernet3/1/1] bfd min-receive-interval 500

[RouterA-GigabitEthernet3/1/1] bfd detect-multiplier 7

[RouterA-GigabitEthernet3/1/1] return

# Enable BFD on Router B and configure BFD parameters.

[RouterB] bfd session init-mode active

[RouterB] interface GigabitEthernet 3/1/1

[RouterB-GigabitEthernet3/1/1] isis ipv6 bfd enable

[RouterB-GigabitEthernet3/1/1] bfd min-transmit-interval 500

[RouterB-GigabitEthernet3/1/1] bfd min-receive-interval 500

[RouterB-GigabitEthernet3/1/1] bfd detect-multiplier 6

4.      Verify configuration:

The following operations are performed on Router A. Operations for Router B are similar. (Details not shown)

# Display the BFD information of Router A.

<RouterA> display bfd session

Total Session Num: 1            Init Mode: Active

 

 IPv6 Session Working Under Ctrl Mode:

 

     Local Discr: 1441                Remote Discr: 1450

       Source IP: FE80::20F:FF:FE00:1202 (link-local address of GigabitEthernet3/1/1 on Router A)

  Destination IP: FE80::20F:FF:FE00:1200 (link-local address of GigabitEthernet3/1/1 on Router B)

   Session State: Up                     Interface: GE3/1/1

       Hold Time:    /

# Display route 2001:4::0/64 on Router A, and you can see that Router A and Router B communicate through the Layer 2 switch.

<RouterA> display ipv6 routing-table 2001:4::0 64 verbose

Routing Table :

Summary Count : 2

 

 Destination  : 2001:4::0                               PrefixLength : 64

 NextHop      : 2001::2                                 Preference   : 15

 RelayNextHop : ::                                      Tag          : 0H

 Neighbor     : ::                                      ProcessID    : 0

 Interface    : GigabitEthernet3/1/1                    Protocol     : ISISv6

 State        : Active Adv                              Cost         : 20

 Tunnel ID    : 0x0                                     Label        : NULL

 Age          : 4538sec

 

 Destination  : 2001:4::0                               PrefixLength : 64

 NextHop      : 2001:2::2                               Preference   : 15

 RelayNextHop : ::                                      Tag          : 0H

 Neighbor     : ::                                      ProcessID    : 0

 Interface    : GigabitEthernet3/1/2                    Protocol     : ISISv6

 State        : Invalid Adv                             Cost         : 30

 Tunnel ID    : 0x0                                     Label        : NULL

 Age          : 4515sec

# Enable BFD debugging on Router A.

<RouterA> debugging bfd scm

<RouterA> debugging bfd event

<RouterA> debugging isis event bfd

<RouterA> terminal debugging

# When the link between Router B and the Layer-2 switch fails, BFD can quickly detect the failure.

#Aug  8 14:54:05:362 2009 RouterA IFNET/4/INTERFACE UPDOWN:

 Trap 1.3.6.1.6.3.1.1.5.3<linkDown>: Interface 983041 is Down, ifAdminStatus is 1, ifOperStatus is 2

#Aug  8 14:54:05:363 2009 RouterA ISIS/4/ADJ_CHANGE:TrapID(1.3.6.1.2.1.138.0.17<isisAdjacencyChange>), ISIS Level-2 Adjencency IN Circuit-983041 State Change.

#Aug  8 14:54:05:364 2008 RouterA ISIS/4/ADJ_CHANGE:TrapID(1.3.6.1.2.1.138.0.17<isisAdjacencyChange>), ISIS Level-1 Adjencency IN Circuit-983041 State Change.

%Aug  8 14:54:05:365 2009 RouterA IFNET/4/LINK UPDOWN: GigabitEthernet3/1/1: link status is DOWN

%Aug  8 14:54:05:366 2008 RouterA IFNET/4/UPDOWN: Line protocol on the interface GigabitEthernet3/1/1 is DOWN

%Aug  8 14:54:05:367 2009 RouterA ISIS/4/ADJLOG:ISIS-1-ADJCHANGE: Adjacency To 0000.0000.0002 (GE3/1/1) DOWN, Level-2 Circuit Down.

%Aug  8 14:54:05:367 2009 RouterA ISIS/4/ADJLOG:ISIS-1-ADJCHANGE: Adjacency To 0000.0000.0002 (GE3/1/1) DOWN, Level-2 Adjacency clear.

%Aug  8 14:54:05:368 2009 RouterA ISIS/4/ADJLOG:ISIS-1-ADJCHANGE: Adjacency To 0000.0000.0002 (GE3/1/1) DOWN, Level-1 Circuit Down.

%Aug  8 14:54:05:369 2009 RouterA ISIS/4/ADJLOG:ISIS-1-ADJCHANGE: Adjacency To 0000.0000.0002 (GE3/1/1) DOWN, Level-1 Adjacency clear.

*Aug  8 14:54:05:369 2009 RouterA ISIS/6/ISIS: ISIS-1-BFD: Recieve BFD session down . Type 0. DstIPAddr: FE80::20F:FF:FE00:1200 , SrcIPAddr: FE80::20F:FF:FE00:1202

*Aug  8 14:54:05:370 2009 RouterA ISIS/6/ISIS: ISIS-1-BFD: Success to send msg. Msg type 1 delete session. IfPhyIndex: 5 ,DstIPAddr: FE80::20F:FF:FE00:1200 , SrcIPAddr: FE80::20F:FF:FE00:1202 . NeighborType: Level-1.

# Display the BFD information of Router A. You can see that Router A has removed its neighbor relationship with Router B and therefore no information is output.

<RouterA> display bfd session

# Display route 2001:4::0/64 on Router A, and you can see that Router A and Router B communicate through Router C.

<RouterA> display ipv6 routing-table 2001:4::0 64 verbose

Routing Table :

Summary Count : 1

 

 Destination  : 2001:4::0                               PrefixLength : 64

 NextHop      : 2001:2::2                               Preference   : 15

 RelayNextHop : ::                                      Tag          : 0H

 Neighbor     : ::                                      ProcessID    : 0

 Interface    : GigabitEthernet3/1/2                    Protocol     : ISISv6

 State        : Invalid Adv                             Cost         : 30

 Tunnel ID    : 0x0                                     Label        : NULL

 Age          : 4610sec