Routing in IPv6

1
Routing in IPv6

• Static Routing
• RIP
• EIGRP
• OSPF

2
RIP for IPv6
3
RIP for IPv6 Overview

• IPv6 RIP functions the same and offers the same
  benefits as RIP in IPv4. RIP enhancements for
  IPv6, detailed in RFC 2080, include support for
  IPv6 addresses and prefixes, and the use of the
  all-RIP-routers multicast group address FF029
  as the destination address for RIP update
  messages.
• New commands specific to RIP in IPv6 were also
  added to the Cisco IOS command-line interface
  (CLI).
• Each IPv6 RIP process maintains a local routing
  table - Routing Information Database (RIB).
• The IPv6 RIP RIB contains a set of best-cost IPv6
  RIP routes learned from all its neighboring
  networking devices.
• If IPv6 RIP learns the same route from two
  different neighbors, but with different costs, it
  will store only the lowest cost route in the
  local RIB.
• The RIB also stores any expired routes that the
  RIP process is advertising to its neighbors
  running RIP. IPv6 RIP will try to insert every
  non-expired route from its local RIB into the
  master IPv6 RIB. If the same route has been
  learned from a different routing protocol with a
  better administrative distance than IPv6 RIP, the
  RIP route will not be added to the IPv6 RIB but
  the RIP route will still exist in the IPv6 RIP
  RIB.

4
Implementing RIP for IPv6

• Three Steps
• Create the routing process
• Enable the routing process on interfaces
• Customize the routing protocol for your
  particular network.

5
Step 1. Enabling IPv6 RIP

• Before configuring the router to run IPv6 RIP,
  globally enable IPv6 using the ipv6
  unicast-routing global configuration command, and
  enable IPv6 on any interfaces on which IPv6 RIP
  is to be enabled.
• STEPS
• enable
• configure terminal
• interface type number
• ipv6 rip name enable

6
Step 2. Customizing IPv6 RIP
Command or Action Purpose
ipv6 router rip word Router(config) ipv6 router rip cisco Configures an IPv6 RIP routing process and enters router configuration mode for the IPv6 RIP routing process. Use the word argument to identify a specific IPv6 RIP routing process.
maximum-paths number-paths Router(config-router) maximum-paths 1 (Optional) Defines the maximum number of equal-cost routes that IPv6 RIP can support. The number-paths argument is an integer from 1 to 64. The default for RIP is four paths.
ipv6 rip name default-information only originate metric metric-value Router(config-if) ipv6 rip cisco default-information originate (Optional) Originates the IPv6 default route (/0) into the specified RIP routing process updates sent out of the specified interface.
7
Verifying IPv6 RIP Configuration and Operation

• A user may want to check IPv6 RIP configuration
  and operation.
• Some of the following scenarios may occur for
  which a user can then enable the following show
  and debug commands
• "Why isn't a certain route appearing in my IPv6
  routing table?"
• "Am I receiving routes via RIP?"
• "Is a certain route being filtered?"
• "Someone at a route site told me that I am not
  advertising a certain route. True?"

8
Verifying IPv6 RIP Configuration and Operation
Command or Action Purpose
show ipv6 rip name database next-hops Routergt show ipv6 rip cisco database (Optional) Displays information about current IPv6 RIP processes. In this example, IPv6 RIP process database information is displayed for the specified IPv6 RIP process.
show ipv6 route ipv6-address ipv6-prefix/prefix-length protocol interface-type interface-number Routergt show ipv6 route rip (Optional) Displays the current contents of the IPv6 routing table. In this example, only IPv6 RIP routes are displayed.
debug ipv6 rip interface-type interface-number Router debug ipv6 rip (Optional) Displays debugging messages for IPv6 RIP routing transactions.
9
show ipv6 rip Command Example

• Routergt show ipv6 rip
• RIP process "cisco", port 521, multicast-group
  FF029, pid 62
• Administrative distance is 120. Maximum paths is
  1
• Updates every 5 seconds, expire after 15
• Holddown lasts 10 seconds, garbage collect after
  30
• Split horizon is on poison reverse is off
• Default routes are generated
• Periodic updates 223, trigger updates 1
• Interfaces
• Ethernet0/0
• Redistribution
• Redistributing protocol bgp 65001 route-map
  bgp-to-rip

10
show ipv6 rip Command Example

• Output information about a specified IPv6 RIP
  process database is displayed using the show ipv6
  rip command with the name argument and the
  database keyword.
• In the following output for the IPv6 RIP process
  named cisco, timer information is displayed, and
  route 20010db816/64 has a route tag set
• Routergt show ipv6 rip cisco database
• RIP process "cisco", local RIB
• 20010db8/64, metric 2
• Ethernet0/0/FE80A8BBCCFFFE00B00, expires in
  13 secs
• 20010db8/16, metric 2 tag 4, installed
• Ethernet0/0/FE80A8BBCCFFFE00B00, expires in
  13 secs
• 20010db81/16, metric 2 tag 4, installed
• Ethernet0/0/FE80A8BBCCFFFE00B00, expires in
  13 secs
• 20010db82/16, metric 2 tag 4, installed
• Ethernet0/0/FE80A8BBCCFFFE00B00, expires in
  13 secs
• /0, metric 2, installed
• Ethernet0/0/FE80A8BBCCFFFE00B00, expires in
  13 secs

11
show ipv6 route Command Example

• Routergt show ipv6 route rip
• IPv6 Routing Table - 17 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
• R 20010db81/32 120/2
• via FE80A8BBCCFFFE00A00, Ethernet0/0
• R 20010db82/32 120/2
• via FE80A8BBCCFFFE00A00, Ethernet0/0
• R 20010db83/32 120/2
• via FE80A8BBCCFFFE00A00, Ethernet0/0

12
Configuration Examples for IPv6 RIP

• ipv6 router rip cisco
• maximum-paths 1
• redistribute bgp 65001 route-map bgp-to-rip
•  distribute-list prefix-list eth0/0-in-flt in
  Ethernet0/0
• !
• interface Ethernet0/0
• ipv6 address 20010db8/64 eui-64
• ipv6 rip cisco enable
• ipv6 rip cisco default-information originate
• !
• ipv6 prefix-list bgp-to-rip-flt seq 10 deny
  20010db83/16 le 128
• ipv6 prefix-list bgp-to-rip-flt seq 20 permit
  20010db81/8 le 128
• !
• ipv6 prefix-list eth0/0-in-flt seq 10 deny /0
• ipv6 prefix-list eth0/0-in-flt seq 15 permit /0
  le 128
• !
• route-map bgp-to-rip permit 10
• match ipv6 address prefix-list bgp-to-rip-flt
• set tag 4

13
Enabling RIPng in Router3 with the Advertisement
of the Default Route
14
EIGRP for IPv6
15
EIGRP for IPv6 Overview

• EIGRP for IPv6 is directly configured on the
  interfaces over which it runs. This feature
  allows EIGRP for IPv6 to be configured without
  the use of a global IPv6 address. There is no
  network statement in EIGRP for IPv6.
• In per-interface configuration at system startup,
  if EIGRP has been configured on an interface,
  then the EIGRP protocol may start running before
  any EIGRP router mode commands have been
  executed.
• An EIGRP for IPv6 protocol instance requires a
  router ID before it can start running.
• EIGRP for IPv6 has a shutdown feature. The
  routing process should be in "no shutdown" mode
  in order to start running.
• When a user uses passive-interface configuration,
  EIGRP for IPv6 does not need to be configured on
  the interface that is made passive.
• EIGRP for IPv6 provides route filtering using the
  distribute-list prefix-list command. Use of the
  route-map command is not supported for route
  filtering with a distribute list.

16
Implementing EIGRP for IPv6

• Enabling EIGRP for IPv6 on an Interface
• Configuring the Percentage of Link Bandwidth Used
  
• Configuring Summary Aggregate Addresses
• Configuring EIGRP Route Authentication
• Adjusting the Interval Between Hello Packets in
  EIGRP for IPv6
• Adjusting the Hold Time in EIGRP for IPv6
• Customizing an EIGRP for IPv6 Routing Process
• Monitoring and Maintaining EIGRP

17
Enabling EIGRP for IPv6 on an Interface
Command or Action Purpose
ipv6 unicast-routing Router(config) ipv6 unicast-routing Enables the forwarding of IPv6 unicast datagrams.
ipv6 enable Router(config-if) ipv6 enable Enables IPv6 processing on an interface that has not been configured with an explicit IPv6 address.
ipv6 eigrp as-number Router(config-if) ipv6 eigrp 1 Enables EIGRP for IPv6 on a specified interface.
ipv6 router eigrp as-number Router(config) ipv6 router eigrp 1 Enters router configuration mode and creates an EIGRP for IPv6 routing process.
router-id ip-address ipv6-address Router(config-router) router-id 10.1.1.1 Enables the use of a fixed router ID.
18
Configuring the Percentage of Link Bandwidth Used

• By default, EIGRP packets consume a maximum of 50
  percent of the link bandwidth, as configured with
  the bandwidth interface configuration command.
• STEPS
• interface  type number
• bandwidth kbps inherit kbps
• ipv6 bandwidth-percent eigrp as-number percent

19
Configuring Summary Aggregate Addresses

• Steps
• interface  type number
• ipv6 summary-address eigrp as-number ipv6-address
  admin-distance
• Router(config) interface FastEthernet 0/ 0
• Router(config-if) ipv6 summary-address eigrp 1
  20010DB801/64

20
Configuring EIGRP Route Authentication - Overview

• EIGRP route authentication provides Message
  Digest 5 (MD5) authentication of routing updates
  from the EIGRP routing protocol.
• The MD5 keyed digest in each EIGRP packet
  prevents the introduction of unauthorized or
  false routing messages from unapproved sources.
• Each key has its own key identifier, which is
  stored locally.
• The combination of the key identifier and the
  interface associated with the message uniquely
  identifies the authentication algorithm and MD5
  authentication key in use.

21
Configuring EIGRP Route Authentication

• interface  type number
• ipv6 authentication mode eigrp as-number md5
• ipv6 authentication key-chain eigrp as-number
  key-chain
• exit
• key chain name-of-chain
• key key-id
• key-string text
• accept-lifetime start-time infinite end-time
  duration seconds
• send-lifetime start-time infinite end-time
  duration seconds

• Example
• Router(config) interface FastEthernet 0/0
• Router(config-if) ipv6 authentication mode eigrp
  1 md5
• Router(config-if) ipv6 authentication key-chain
  eigrp 1 chain1
• Router(config-if) exit
• Router(config) key chain chain1
• Router(config-keychain) key 1
• Router(config-keychain-key) key-string chain 1
• Router(config-keychain-key) accept-lifetime
  143000 Jan 10 2006 duration 7200
• Router(config-keychain-key) send-lifetime
  150000 Jan 10 2006 duration 3600

22
Monitoring and Maintaining EIGRP

• Use of clear and debug commands helps users
  monitor and maintain their EIGRP for IPv6
  environments.
• Deleting Entries from EIGRP for IPv6 Routing
  Tables
• clear ipv6 eigrp as-number neighbor
  ipv6-address interface-type interface-number
  
• Router clear ipv6 eigrp neighbor
  3FEE12E12AC1EA32

23
Adjusting the Interval Between Hello Packets in
EIGRP for IPv6

• Routing devices periodically send hello packets
  to each other to dynamically learn of other
  routers on their directly attached networks.
• This information is used to discover neighbors
  and to learn when neighbors become unreachable or
  inoperative.
• By default, hello packets are sent every 5
  seconds.
• The exception is on low-speed, nonbroadcast
  multiaccess (NBMA) media, where the default hello
  interval is 60 seconds.
• Low speed is considered to be a rate of T1 or
  slower, as specified with the bandwidth interface
  command.
• The hold time is advertised in hello packets and
  indicates to neighbors the length of time they
  should consider the sender valid.
• The default hold time is three times the hello
  interval, or 15 seconds.
• For slow-speed NBMA networks, the default hold
  time is 180 seconds.

24
Adjusting the Interval Between Hello Packets in
EIGRP for IPv6

• interface  type number
• ipv6 hello-interval eigrp as-number seconds
• Router(config) interface FastEthernet 0/0
• Router(config) ipv6 hello-interval eigrp 1 10

25
Adjusting the Hold Time in EIGRP for IPv6

• On very congested and large networks, the default
  hold time might not be sufficient time for all
  routers to receive hello packets from their
  neighbors.
• In this case, you may want to increase the hold
  time.
• ipv6 hold-time eigrp as-number seconds
• Router(config-if) ipv6 hold-time eigrp 1 40

26
Customizing an EIGRP for IPv6 Routing Process

• After you have enabled EIGRP for IPv6 on a
  specific interface, you can configure an EIGRP
  for IPv6 routing process.
• The following optional tasks provide information
  on how to configure an EIGRP for IPv6 routing
  process to suit your needs
• Logging EIGRP Neighbor Adjacency Changes
• Configuring Intervals Between Neighbor Warnings

27
Logging EIGRP Neighbor Adjacency Changes

• You can enable the logging of neighbor adjacency
  changes to monitor the stability of the routing
  system and to help you detect problems.
• By default, adjacency changes are not logged.
• Use the following task to enable such logging
• interface  type number
• ipv6 router eigrp as-number
• log-neighbor-changes
• Router(config) interface FastEthernet 0/0
• Router(config-if) ipv6 router eigrp 1
• Router(config-router) log-neighbor-changes

28
Configuring Intervals Between Neighbor Warnings

• When neighbor warning messages occur, they are
  logged by default.
• Use the following task to configure the interval
  between neighbor warning messages.
• interface  type number
• ipv6 router eigrp as-number
• log-neighbor-warnings seconds
• Router(config) interface FastEthernet 0/0
• Router(config-if) ipv6 router eigrp 1
• Router(config-router) log-neighbor-warnings 300

29
Debugging Commands to Troubleshoot an EIGRP for
IPv6 Environment

• debug eigrp fsm
• debug eigrp neighbor siatimer static
• debug eigrp packet
• debug eigrp transmit ack build detail
  link packetize peerdown sia startup
  strange
• debug ipv6 eigrp as-number neighbor
  ipv6-address notification summary

30
Configuring EIGRP to Establish Adjacencies on an
Interface

• ipv6 unicast-routing
• interface e0
•   ipv6 enable
•   ipv6 eigrp 1
•   no shutdown
• !
• ipv6 router eigrp 1
• router-id 10.1.1.1
• no shutdown