In this post, I will show you how to configure IPv6 addresses on an interface using Modified EUI-64 in Packet Tracer. EUI stands for Extended Unique Identifier, also referred to as EUI-64. It is a method of converting a MAC address (48 bits) into a 64-bit interface identifier. This interface identifier will now be the host portion of a /64 IPv6 address. An IPv6 address, as we know, is 128 bits, so /64 means that 64 bits are for the host portion and 64 bits are for the network portion.
How to Convert MAC address to EUI-64 interface Identifier
Step 1: Divide the Mac address in half.
The first step is to divide the Mac address in half. For instance, if we are given 1234 5678 90AB as the Mac address, we write it as 1234 56 | 78 90AB.
Step 2: Insert FFFE in the middle.
After dividing the Mac address into two, we had 1234 56 | 78 90AB. Now, inserting FFFE in the middle, we will have 1234 56 FFFE 78 90AB.
Step 3: Invert the seventh bit.
Because each hexadecimal digit is four bits, the seventh bit will always be on the second hexadecimal number. In the mac address considered above, the seventh bit lies within the binary value of 2. 2 converted to binary is 0010. This means that the seventh bit is 1. So we will invert it to 0 to give us 0000.
Hence, the interface identifier is 103456FFFE7890AB.
Network Topology
The network topology we will be making use of in this post is shown below. As you can see, it consist of two routers, two switches and two PCs. In this demonstration, We will configure IPV6 address on the g0/1 interface of both R1 and R2 using EUI-64 interface ID.
Download the premade lab file or recreate the network topology shown below on your packet tracer software.
Lab Task
The objective of this lab is to calculate the EUI64 interface ID using the mac address of the Cisco routers and use it to configure the IPv6 interface address on the Cisco routers. Here are the steps for what to do:
- Use EUI-64 to configure IPv6 addresses on G0/1 of R1/R2. *Before configuring the addresses, calculate the EUI-64 interface ID that will be generated on each interface.
- Configure the appropriate IPv6 addresses and default gateways on PC1 and PC2.
- Enable IPv6 on G0/0 of R1/R2 without explicitly configuring an IPv6 address.
- Note: Interfaces are enabled and configured with IPv4.
Lab Solution
Here is the configuration needed to be completed on the lab;
For g0/1 interface of R1
Converting the MAC address into IPV6 address
Firstly, let get the mac address of the interface;
R1>enable
R1#show interfaces g0/1
GigabitEthernet0/1 is up, line protocol is up (connected)
Hardware is CN Gigabit Ethernet, address is 0030.f236.4502 (bia 0030.f236.4502)
Internet address is 10.0.1.254/24
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not setFrom the show command, the R1 g0/1 interface mac address is: 0030.f236.4502
Split it into two…
0030.f2 36.4502
Insert fffe in the center
0030.f2ff fe36.4502
Convert the seventh bit to 1(and convert back from binary to hexadecimal)
0230.f2ff.fe36.4502
0230.f2ff.fe36.4502 is the EUI-64 interface Identifier of the g0/1 interface of R1
And lastly append it to the network prefix.
2001: db8:230: f2ff: fe36:4502/64
Configuring R1 g0/1 interface using EUI interface ID
R1>enable
R1#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#ipv6 unicast-routing <------this enable IPV6 routing on the the router
R1(config)#interface g0/1
R1(config-if)#ipv6 address 2001:db8::/64 ?
anycast Configure as an anycast
eui-64 Use eui-64 interface identifier
R1(config-if)#ipv6 address 2001:db8::/64 eui-64
R1(config-if)#do show ipv6 interface brief
GigabitEthernet0/0 [up/up]
unassigned
GigabitEthernet0/1 [up/up]
FE80::230:F2FF:FE36:4502
2001:DB8::230:F2FF:FE36:4502 —---> Same with what was calculated
GigabitEthernet0/2 [administratively down/down]
unassigned
Vlan1 [administratively down/down] For g0/1 interface of R2
Converting the MAC address into IPV6 address
R2>enable
R2#show interfaces g0/1
GigabitEthernet0/1 is up, line protocol is up (connected)
Hardware is CN Gigabit Ethernet, address is 0001.63b0.b802 (bia 0001.63b0.b802)
Internet address is 10.0.2.254/24
Then mac address is 0001.63b0.b802
Following the same steps, the IPV6 address of the interface is gotten from the mac address as follow;
R2: G0/1
MAC: 0001.63b0.b802
0001.63 b0.b802
0001.63ff feb0.6802
0201.63ff.feb0.6802 is the EUI 64 interface ID.
2001: db8:0:1:201:63ff:feb0:b802 is the ipv6 address
Configuring R1 g0/1 interface using EUI interface ID
R2#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#ipv6 unicast-routing
R2(config)#interface g0/1
R2(config-if)#ipv6 address 2001:db8:0:1::/64 ?
anycast Configure as an anycast
eui-64 Use eui-64 interface identifier
R2(config-if)#ipv6 address 2001:db8:0:1::/64 eui-64
R2(config-if)#do show ipv6 interface brief
GigabitEthernet0/0 [up/up]
unassigned
GigabitEthernet0/1 [up/up]
FE80::201:63FF:FEB0:B802
2001:DB8:0:1:201:63FF:FEB0:B802
GigabitEthernet0/2 [administratively down/down]
unassigned
Vlan1 [administratively down/down]
Configuring IPV6 address on host devices
On PC 1
On PC2
Configuring Link local IPV6 address (for Step 3)
IPV6 can be enabled on an interface without explicitly configuring an IPv6 address on the interface. To do this, we use the command “IPV6 enable.” This will automatically configure link local IPV6 address on that interface.
On R1
R1>enable
R1#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#interface g0/0
R1(config-if)#ipv6 enable
R1(config-if)#do show ipv6 interface brief
GigabitEthernet0/0 [up/up]
FE80::230:F2FF:FE36:4501
GigabitEthernet0/1 [up/up]
FE80::230:F2FF:FE36:4502
2001:DB8::230:F2FF:FE36:4502
GigabitEthernet0/2 [administratively down/down]
unassigned
Vlan1 [administratively down/down] On R2
R2>enable
R2#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#interface g0/1
R2(config-if)#ipv6 enable
R2(config-if)#do show ipv6 interface brie
GigabitEthernet0/0 [up/up]
unassigned
GigabitEthernet0/1 [up/up]
FE80::201:63FF:FEB0:B802
2001:DB8:0:1:201:63FF:FEB0:B802
GigabitEthernet0/2 [administratively down/down]
unassigned
Vlan1 [administratively down/down] That is all, you can Download the premade lab solution to check and compare your own work
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