I am interested to do socket programming. I would like send and receive Ipv6 UDP server socket programming for raspberry (conneted with ethernet cable and opened in Putty). After surfing coulpe of sites I have got confusion with IPv6 UDP host address. Which type of host address should I use to send and receive message ipv6 UDP message.
is the link local address
example:
host ='fe80::ba27:ebff:fed4:5691';//link local address to Tx and Rx from Raspberry
or
host = 'ff02::1:ffd4:5691'
Thank you so much.
Regards,
Mahesh
You can use host ='fe80::ba27:ebff:fed4:5691', assuming you only have one link. 
Link-Local addresses (Link-Local scope) are designed to be used for addressing on a single link for purposes such as automatic address configuration, neighbor discovery or when no routers are present. Routers must not forward any packets with Link-Local source or destination addresses to other links.
So if you are sending data from a server to a raspberry pi (1 link), you can use the link-local scope for you IPv6 address.
host = 'ff02::1:ffd4:5691' is the link-local multicast scope, unless you have a reason to send multicast, there is no need.
Ipv6 UDP host address for bind