How to ping ipv6 interface

I'm trying to get familiar with ipv6 I don't understand why I can't ping this interface at the inet6 addr

eth1      Link encap:Ethernet  HWaddr 08:00:27:77:9e:77  
          inet addr:192.168.33.10  Bcast:192.168.33.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:fe77:9e77/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:363 errors:0 dropped:0 overruns:0 frame:0
          TX packets:332 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:38402 (38.4 KB)  TX bytes:81402 (81.4 KB)
          Interrupt:16 Base address:0xd060 

$bash ping6 fe80::a00:27ff:fe77:9e77
connect: Invalid argument

Solution 1:

You forgot the scope identifier, which is required to identify which link the link-local address you specified refers to.

If the address you want is reachable through the eth1 interface, then you specify it:

ping6 fe80::a00:27ff:fe77:9e77%eth1