Experts,
Can you please confirm me if we should a Loopback interface on the router where 6 to 4 tunnel is configured and that Lo interface should match our site local address.
R1-R2 is running Ipv6 ospf
R3-R4 is running Ipv6 ospf
R5-R6 is running Ipv6 ospf
EIGRP is running in ipv4 backbone.
R1#sh ipv6 int bri
FastEthernet0/0 [up/up]
FE80::CE04:1AFF:FE04:0
2001:202:202:12::1
R1-R2 site is running 2001:0202:0202/48 site address
R4#sh ipv6 int bri
FastEthernet0/0 [up/up]
FE80::CE07:1AFF:FE04:0
2001:303:303:34::4
R3-R4 site is running 2001:0303:0303/48 site address
R3 is having a loopback interface 3.3.3.3.
Here is the tunnel config:
R2#sh run int tu0 | b interface
interface Tunnel0
no ip address
no ip redirects
ipv6 unnumbered Loopback0
tunnel source Loopback0
tunnel mode ipv6ip 6to4
end
When I change the IP of the Lo interface from 3.3.3.3 to anything else then the communication fails.
R3(config-if)#ip add 33.33.33.33 255.255.255.0
R3(config-if)#
R1#p 2001:303:303:34::4 re 3
Type escape sequence to abort.
Sending 3, 100-byte ICMP Echos to 2001:303:303:34::4, timeout is 2 seconds:
...
Success rate is 0 percent (0/3)
Reverting the change.
R3(config-if)#ip add 3.3.3.3 255.255.255.0
R3(config-if)#
R1#p 2001:303:303:34::4 re 3
Type escape sequence to abort.
Sending 3, 100-byte ICMP Echos to 2001:303:303:34::4, timeout is 2 seconds:
!!!
Success rate is 100 percent (3/3), round-trip min/avg/max = 52/80/104 ms
Can you please tell why this is so?