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IPv4 has 4.3 billion addresses, which may seem mindboggling. However, it took only two decades for it to reach its depletion. IPv6 has come to the rescue in the form of 128-bit addresses. Packet Tracer supports a wide array of IPv6 features. We’ll start by learning how to assign IP addresses to different devices and how to configure routing between them. Finally, we’ll create a setup that enables IPv6 communication over IPv4 devices.
Assigning IPv6 addresses
Starting from Packet Trace Version 6, the IP Configuration utility under the Desktop tab of end devices has an option to enter an IPv6 address. Let’s begin with a simple topology consisting of two PCs and a router connected to a switch, as shown in the following screenshot:
There are three ways of assigning IPv6 addresses to a device and we’ll see each one of them.
Autoconfiguration requires the least amount of configuration but makes it difficult to remember the IPv6 addresses. This method uses the MAC address of the device to create an IPv6 address with the FE80:: prefix. Carry out the following steps to assign IPv6 addresses using Autoconfiguration:
- Begin by configuring the router. Enter the interface configuration mode and enable IPv6 on the interface.
R0(config)#ipv6 unicast-routing R0(config)#interface FastEthernet0/0 R0(config-if)#ipv6 enable
- Next, we will configure a link local address and a global unicast address on this interface. We’ll use eui-64 to reduce the configuration.
R0(config-if)#ipv6 address autoconfig R0(config-if)#ipv6 add 2000::/64 eui-64 R0(config-if)#no shutdown
- Verify that the interface is up and has two IPv6 addresses.
R0>sh ipv6 interface brief FastEthernet0/0 [up/up] FE80::2D0:58FF:FE65:E701 2000::2D0:58FF:FE65:E701
- These IPv6 addresses may vary when you try them out, as they are based on the MAC address. Enable routing so that this router can be identified as a default gateway.
- The configuration of the router is now done, let’s move on to the PCs. Go to the Desktop tab of the PC, open IP Configuration , and under the IPv6 Configuration section, choose Auto Config . The gateway and the PC’s IP address will be assigned automatically, as shown in the following screenshot:
- Use the simple PDU tool to test the connectivity; you’ll see ICMPv6 packets moving between the nodes. To view the IPv6 address from the command line of PCs, use the ipv6config command.
IPv6 addresses can also be assigned statically on all devices. We’ll use the same topology for this section too. We’ll carry out the following steps to configure IPv6 addresses statically:
- Begin by configuring a static IPv6 address on the router.
R0(config)#interface fastethernet0/0 R0(config-if)#ipv6 enable R0(config-if)#ipv6 address 2000::1/64 R0(config-if)#no shutdown
- Go to the Desktop tab of PC, open the IP Configuration utility, and enter an IPv6 address with the same prefix.
- Now use the simple PDU tool to test the connectivity. Once both the methods work fine, you can have a look at the IPv6 neighbors table. This is similar to the ARP table of IPv4.
R0#sh ipv6 neighbor IPv6 Address Age Link-layer Addr State Interface 2000::2 0 00E0.A39E.05C4 REACH Fa0/0 2000::3 0 0001.43B9.0268 REACH Fa0/0
Now that we have configured IPv6 addresses on a single network, let’s configure them on more networks and enable routing between them.
IPv6 static and dynamic routing
Similar to IPv4, IPv6 too supports both static and dynamic routing. Configuration commands for its static routing are similar to IPv4.
Modifying the same topology that we used previously, let’s add a router, switch, and two PCs to create a separate network, as shown in the following screenshot:
The first network will use addresses starting from 2000:1::/64 and the second network will use addresses starting from 2000:2::/64. The link between both the routers will have IP addresses 2001::10/64 and 2001::20/64.
Here is a table describing the topology:
After the necessary IP addresses and gateways have been assigned, open the CLI tab for the R1 router, and start configuring routing by following the given commands:
R1(config)#ipv6 unicast-routing R1(config)#ipv6 route 2000:2::/64 2001::20
Next, open the CLI tab for R2 and configure routing on it.
R2(config)#ipv6 unicast-routing R2(config)#ipv6 route 2000:1::/64 2001::10
Now use the simple PDU tool to test the connectivity. You may also use the tracert command on a PC to see the path a packet takes.
PC>tracert 2000:2::3 Tracing route to 2000:2::3 over a maximum of 30 hops: 1 63 ms 63 ms 47 ms 2000:1::1 2 94 ms 78 ms 94 ms 2001::20 3 156 ms 109 ms 129 ms 2000:2::3 Trace complete.
Packet Tracer offers the same dynamic routing protocols for IPv6: RIPv6, EIGRP, and OSPF. We’ll be configuring RIPv6 in this section. Note that RIPv6 does not represent RIP Version 6; it is RIP for IPv6 addresses.
For this exercise, we’ll use the topology shown in the following screenshot:
The additional IP assignment details alone are shown in the following table:
We’ll see how to configure RIP on one router and you can do the same on the others.
R1(config)#interface FastEthernet0/0 R1(config-if)#ipv6 address 2000:1::1/64 R1(config-if)#ipv6 rip Net1 enable R1(config-if)#ipv6 enable R1(config-if)#interface FastEthernet0/1 R1(config-if)#ipv6 address 2001::10/64 R1(config-if)#ipv6 rip Net1 enable R1(config-if)#ipv6 enable
Note that the ipv6 rip command is used to enable RIP on a particular interface. Entering ipv6 rip Net1 enable on the first interface begins the RIPv6 process. The Net1 string can be any name that can be used to name the RIP process. Once configured, use the usual diagnostic tools (ping to simple PDU) to check the connectivity. To view the RIP database, use the following command:
R1#sh ipv6 rip database RIP process “Net1” local RIB 2000:2::/64, metric 2, installed FastEthernet0/1/FE80::201:97FF:FE87:E5A9, expires in 173 sec 2000:3::/64, metric 3, installed FastEthernet0/1/FE80::201:97FF:FE87:E5A9, expires in 173 sec 2001::/64, metric 2 FastEthernet0/1/FE80::201:97FF:FE87:E5A9, expires in 173 sec 2001:1::/64, metric 2, installed FastEthernet0/1/FE80::201:97FF:FE87:E5A9, expires in 173 sec RIP process “LINK” local RIB
Trace the route of the packet to see the path it takes.
Tracing route to 2000:3::2 over a maximum of 30 hops: 1 31 ms 32 ms 31 ms 2000:1::1 2 50 ms 50 ms 63 ms 2001::20 3 94 ms 94 ms 94 ms 2001:1::20 4 125 ms 109 ms 125 ms 2000:3::2 Trace complete.
In this article, we learned how to use IPv6 with Packet Tracer. We saw the limitation of the IPv4 addresses. We also learned how to assign IPv6 addresses and how to configure IPv6 static and dynamic routing.