ipv6 routing

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IPv6 Routing


AgendaIPv6 Routing Table

Connected Routes

Local Routes

Static Routing

Default Route


Very Very Important IPv6 routing is turned off by default on Cisco IOS

So please issue the command

ipv6 unicast-routing in global configuration mode to enable IPv6 Routing

For Eg: R1(config)#ipv6 unicast-routing


Topology


IPv4 Routing TableR1#sh ip route

C 172.17.0.0/16 is directly connected, Loopback3

172.16.0.0/24 is subnetted, 1 subnets

C 172.16.1.0 is directly connected, FastEthernet0/1

10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks


C 10.1.1.0/24 is directly connected, FastEthernet0/0


IPv4 Routing table lists the classful network first and subnets below the respective classful network


IPv6 Routing TableThere are no classes in IPv6 IPv6 Routing Table lists the routes as individual networks


Topology


R1’s Routing TableLet’s see the routing table of R1


“Connected Routes”What are this “C” Routes?

R1 has 3 interfaces on which Global IPv6 Unicast Address have been configured

These interfaces are in up and up state.

So the IPv6 Prefix and Prefix length of these interfaces are added as Directly Connected Routes “C” in the IPv6 Routing Table.


Connected RoutesTask- List the connected routes based on the output of “show ipv6 interface brief”( R2)

Assume the prefix length to be 64


R1’s Routing Table RevisitedLet’s revisit R1’s IPv6 Routing table

What are these “L” Routes?


Local Routes“L” means Local Routes Host routes to the router’s IPv6 Global Unicast addresses

The router uses these routes when the packets are addressed to one of its interfaces

Host route in IPv6 will have /128 prefix

Please note: They are “NOT” routes to link local IPv6 Addresses

Let’s issue “show ipv6 interface brief” on R1 and then issue

“Show ipv6 route” to identify Local Routes


Local Routes

What are these 2 routes?


Local RoutesFF00/8 is the route to entire multicast range

The router will drop all multicast packets directed towards multicast groups which are not in the routing table.

If a host joins a multicast group then that multicast group address will be added to the routing table.

FE80/10 is the link local address.

So if a router receives a packet destined to link local address it will drop it.

L FE80::/10 [0/0] does not appear in the output of show ipv6 route in Packet Tracer


Local RoutesTask- List the connected routes based on the output of “show ipv6 interface brief”( R3)


Static RoutingStatic Routing is configured using ipv6 route command

Let’s take an example

ipv6 route 2001:db8:cafe:3333 /64 s0/0/1

Prefix Prefix Length Outgoing Interface


Static Routing In point to point networks next hop is not required

For eg

ipv6 route 2001:db8:cafe:3333 /64 s0/0/1

We can also have global unicast address as the next hop

ipv6 route 2001:db8:cafe:3333 /64 2001:db8:cafe:A003

We can also have link local address as the next hop but we need to mention the outgoing interface as the link local address can be same on different interfaces

ipv6 route 2001:db8:cafe:3333 /64 fe80::3 s0/0/0

Let’s configure some static routes


Static Routing Configure a static route from R1 to reach R3’s L0 interface or 2001:db8:cafe:3333::3/128

Do not use any next hop ipv6 address (Global Unicast or Link Local)


PT ActivityOpen Routing_IPv6_Static_Route_Exit_interface in the PT folder


Static Routing Step 1:

Enable ipv6 unicast-routing on R1

R1(config)#ipv6 unicast-routing

Step 2:

Configure the static route

R1(config)#ipv6 route 2001:db8:cafe:3333::/64 s0/0/0

Step 3 :




Static Routing Step 4 : Issue show ipv6 route command


Static RoutingStep 5:

Verify the connectivity from R1 using Ping

R1#ping 2001:db8:cafe:3333::3

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2001:db8:cafe:3333::3, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 5/7/11 ms



Use Global IPv6 address as the next hop


PT ActivityOpen Routing_IPv6_Static_Route_Global_Unicast_as_Next_Hop in the PT folder





Step 2:


R1(config)#ipv6 route 2001:db8:cafe:3333::/64 2001:db8:cafe:A001::3

Step 3 :




Static Routing Step 4:Issue the show ipv6 route command on R1




R1#ping 2001:db8:cafe:3333::3



!!!!!




Use link local address of R2 as the next hop


PT ActivityOpen Routing_IPv6_Static_Route_Link_Local_as_Next_Hop in the PT folder





Step 2:


R1(config)#ipv6 route 2001:db8:cafe:2222::/64 s0/0/1 fe80::2

Step 3 :




Static Routing Step 4:Issue the show ipv6 route command




R1#ping 2001:db8:cafe:2222::2


Sending 5, 100-byte ICMP Echos to 2001:db8:cafe:2222::2 timeout is 2 seconds:

!!!!!



Static Routing :Floating Static IPv6 Route Configure a static route from R3 to reach R2’s L0 interface or 2001:db8:cafe:2222::2/128

Use global unicast address as the next hop. Let the AD be 1

Configure a static route from R3 to reach R2’s L0 interface or 2001:db8:cafe:2222::2/128

Use link local address of R2 as the next hop.Let the AD be 5


Static Routing


PT ActivityPlease open Routing_IPv6_Static_Route_Floating_Static_Route in the PT folder.





Step 2:

Configure the static routes

R3(config)# ipv6 route 2001:DB8:CAFE:2222::/64 2001:DB8:CAFE:A003::2

R3(config)# ipv6 route 2001:DB8:CAFE:2222::/64 Serial0/0/1 FE80::2 5

Step 3 :




Static Routing Step 4:Issue the show ipv6 route command on R3




R3#ping 2001:db8:cafe:2222::2



!!!!!




Let us the remove the static route

R3(config)# no ipv6 route 2001:DB8:CAFE:2222::/64 2001:DB8:CAFE:A003::2



Issue show ipv6 route on R3




R3#ping 2001:db8:cafe:2222::2



!!!!!



Default RouteConfigure a Default route on R1 pointing towards 2001:db8:cafe:A001::3


PT ActivityPlease open Routing_IPv6_Default_Route in the PT folder.





Step 2:

Configure the default route

R1(config)#ipv6 route ::/0 2001:db8:cafe:A001::3

Step 3 :




Static Routing Step 4:Issue the show ipv6 route command




R1#ping 2001:db8:cafe:3333::3



!!!!!



Other Routing ProtocolsSingle Area OSPF v3 : Next Session

EIGRP v3 : We will cover it in Teach the Trainer session for ICND2


Question and Answers

Thank you.Thank you.

ipv6 routing

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