IPv6: Configuring Automatic 6to4 tunnels

IPv6: Configuring Automatic 6to4 tunnels

 

·         Automatic 6to4 tunnels are multipoint by default.

·         This is used for IPv6/IPv4

·         Only source is mentioned

·         Since the tunnel is automatic tunnel, we need not mention the tunnel destination.

·         Tunnel mode is set to ipv6ip 6to4

·         Tunnel interface is assigned with ipv6 address, which uses special addressing, 2002 followed by the translated IPv4 address of the interface on the router.

·         Let me take a small 3 roter topology for creating 6to4 tunnels:

Let me see the configs before creating tunnels:

 

R1(config-router)#do show run int fa0/0

Building configuration...

 

Current configuration : 94 bytes

!

interface FastEthernet0/0

 ip address 10.1.12.1 255.255.255.0

 duplex auto

 speed auto

end

 

R1(config-router)#do show run int loop0

Building configuration...

 

Current configuration : 63 bytes

!

interface Loopback0

 ip address 1.1.1.1 255.255.255.255

end

 

R1(config-router)#do show ip route ospf

     2.0.0.0/32 is subnetted, 1 subnets

O       2.2.2.2 [110/11] via 10.1.12.2, 00:14:32, FastEthernet0/0

     3.0.0.0/32 is subnetted, 1 subnets

O       3.3.3.3 [110/21] via 10.1.12.2, 00:14:32, FastEthernet0/0

     10.0.0.0/24 is subnetted, 2 subnets

O       10.1.23.0 [110/20] via 10.1.12.2, 00:14:32, FastEthernet0/0

R1(config-router)#do ping 3.3.3.3

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/28/72 ms

R1(config-router)#do ping 2.2.2.2

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/24/56 ms

R1(config-router)#

 

 

R2(config-router)#do show run int fa0/0

Building configuration...

 

Current configuration : 94 bytes

!

interface FastEthernet0/0

 ip address 10.1.12.2 255.255.255.0

 duplex auto

 speed auto

end

 

R2(config-router)#do show run int fa0/1

Building configuration...

 

Current configuration : 94 bytes

!

interface FastEthernet0/1

 ip address 10.1.23.2 255.255.255.0

 duplex auto

 speed auto

end

 

R2(config-router)#do show run int loop0

Building configuration...

 

Current configuration : 63 bytes

!

interface Loopback0

 ip address 2.2.2.2 255.255.255.255

end

 

R2(config-router)#do show ip route ospf

     1.0.0.0/32 is subnetted, 1 subnets

O       1.1.1.1 [110/11] via 10.1.12.1, 00:15:17, FastEthernet0/0

     3.0.0.0/32 is subnetted, 1 subnets

O       3.3.3.3 [110/11] via 10.1.23.3, 00:15:17, FastEthernet0/1

R2(config-router)#do ping 1.1.1.1

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/20/44 ms

R2(config-router)#do ping 3.3.3.3

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/25/68 ms

R2(config-router)#

 

 

R3(config-router)#do show run int fa0/1

Building configuration...

 

Current configuration : 94 bytes

!

interface FastEthernet0/1

 ip address 10.1.23.3 255.255.255.0

 duplex auto

 speed auto

end

 

R3(config-router)#do show run int loop0

Building configuration...

 

Current configuration : 63 bytes

!

interface Loopback0

 ip address 3.3.3.3 255.255.255.255

end

 

R3(config-router)#do show ip route ospf

     1.0.0.0/32 is subnetted, 1 subnets

O       1.1.1.1 [110/21] via 10.1.23.2, 00:22:13, FastEthernet0/1

     2.0.0.0/32 is subnetted, 1 subnets

O       2.2.2.2 [110/11] via 10.1.23.2, 00:22:13, FastEthernet0/1

     10.0.0.0/24 is subnetted, 2 subnets

O       10.1.12.0 [110/20] via 10.1.23.2, 00:22:13, FastEthernet0/1

R3(config-router)#

R3(config-router)#do ping 2.2.2.2

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/16/36 ms

R3(config-router)#do ping 1.1.1.1

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/31/64 ms

R3(config-router)#

 

·         Let me add ipv6 addresses to loop0 interfaces on all 3 routers:

 

R1(config)#ipv6 unicast-routing

R1(config)#int loop0

R1(config-if)#ipv6 address 2002:0101:0101:1::1/64

R1(config-if)#

 

Observation:

·         ipv6 address is determined as follows, 2002 followed by HEX of R1’s ipv4 loopback0 address, 1.1.1.1 in hex format is 0101:0101

 

R2(config-router)#ipv6 unicast-routing

R2(config)#int loop0

R2(config-if)#ipv6 address 2002:0202:0202:1::2/64

R2(config-if)#

 

Observation:

·         ipv6 address is determined as follows, 2002 followed by HEX of R2’s ipv4 loopback0 address, 2.2.2.2 in hex format is 0202:0202

 

R3(config-router)#ipv6 unicast-routing

R3(config)#int loop0

R3(config-if)#ipv6 address 2002:0303:0303:1::3/64

R3(config-if)#

 

Observation:

·         ipv6 address is determined as follows, 2002 followed by HEX of R3’s ipv4 loopback0 address, 3.3.3.3 in hex format 0303:0303

 

·         Now, let me create 6to4 tunnels to reach these newly added ipv6 interfaces:

 

R1(config)#int tun 1

R1(config-if)#ipv6 address 2002:0101:0101::1/64

R1(config-if)#tunnel source 1.1.1.1

R1(config-if)#tunnel mode ipv6ip 6to4

R1(config-if)#

*Mar  1 00:39:43.359: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel1, changed state to up

R1(config-if)#

 

Observation:

·         ipv6 address is determined as follows, 2002 followed by HEX of R1’s ipv4 loopback0 address, 1.1.1.1 in hex format is 0101:0101

 

R2(config-if)#int tun1

R2(config-if)#ipv6 address 2002:0202:0202::2/64

R2(config-if)#tunnel source 2.2.2.2

R2(config-if)#tunnel mode ipv6ip 6to4

R2(config-if)#

*Mar  1 00:35:18.535: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel1, changed state to up

R2(config-if)#

 

Observation:

·         ipv6 address is determined as follows, 2002 followed by HEX of R2’s ipv4 loopback0 address, 2.2.2.2 in hex format is 0202:0202

 

R3(config)#int tun1

R3(config-if)#ipv6 address 2002:0303:0303::3/64

R3(config-if)#tunnel source 3.3.3.3

R3(config-if)#tunnel mode ipv6ip 6to4

R3(config-if)#

*Mar  1 00:36:05.791: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel1, changed state to up

R3(config-if)#

 

Observation:

·         ipv6 address is determined as follows, 2002 followed by HEX of R3’s ipv4 loopback0 address, 3.3.3.3 in hex format 0303:0303

 

·         Now, let me create default route pointing towards tunnel interface:

 

R1(config)#ipv6 route 2002::/16 tun1

R1(config)#

 

R2(config)#ipv6 route 2002::/16 tun1

R2(config)#

 

R3(config)#ipv6 route 2002::/16 tun1

R3(config)#

 

·         Now, let me check the connectivity:

 

R1(config)#do ping  2002:0202:0202::2

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:202:202::2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/25/44 ms

R1(config)#do ping 2002:0202:0202:1::2

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:202:202:1::2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 0/18/52 ms

R1(config)#do ping 2002:0303:0303::3

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:303:303::3, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/33/76 ms

R1(config)#do ping 2002:0303:0303:1::3

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:303:303:1::3, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/30/48 ms

R1(config)#

 

Observation:

·         R1 is able to ping R2’s tunnel interface and loopback0 interface

·         R1 is able to ping R3’s tunnel interface and loopback0 interface

 

 

R2(config)#do ping 2002:0101:0101::1

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:101:101::1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 0/20/52 ms

R2(config)#do ping 2002:0101:0101:1::1

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:101:101:1::1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/23/76 ms

R2(config)#do ping 2002:0303:0303::3

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:303:303::3, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/27/72 ms

R2(config)#do ping 2002:0303:0303:1::3

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:303:303:1::3, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/17/52 ms

R2(config)#

 

Observation:

·         R2 is able to ping R1’s tunnel interface and loopback0 interface

·         R2 is able to ping R3’s tunnel interface and loopback0 interface

 

R3(config)#do ping 2002:0101:0101::1

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:101:101::1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/32/84 ms

R3(config)#do ping 2002:0101:0101:1::1

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:101:101:1::1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/26/64 ms

R3(config)#do ping  2002:0202:0202::2

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:202:202::2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/24/76 ms

R3(config)#do ping 2002:0202:0202:1::2

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2002:202:202:1::2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/26/64 ms

R3(config)#

 

Observation:

·         R3 is able to ping R1’s tunnel interface and loopback0 interface

·         R3 is able to ping R2’s tunnel interface and loopback0 interface