vSRX Not Allowing IPv6 Packets 2001:db8::

Hi,

I am new to IPv6 and currently I have to do a little configuration but incurred a problem. I have vSRX(12.1) and Ubunutu connected directly to each other.

when I assign 2001:db8:: IP addresses they are unable to ping.

SRX(2001:db8::254/64)-----------------------------------------------Ubunutu(2001:db8::1/64)

However when I assign fec0:: subnet  it works fine, even NT46 work perfectly.

Ofcourse IPv6 is enabled on vSRX.

I checked Ubuntu forum and it says this:

"IPv6 address range 2001:db8::/32 is reserved for documentation only and packets with these addresses should never exist on a network. All routers must discard packet with such addresses. "

Reference link is 

http://askubuntu.com/questions/256138/why-am-i-unable-to-ping-the-same-interface-after-configuring-an-ipv6-address

Go to second to last comment.

If Anyone could explian this I'd appreciate.

Thanks,

MYN