[c-nsp] IPv6 deployment

[Edward Iong]

Dear All,
 
We are planning to implement IPv6 to our existing IPv4 network.
 
There are several things I would like to ask:-
 
1. Can IPv4 and IPv6 devices exist at the same time in the same LAN? and can they communicate with each other?
2. If both IPv4 and IPv6 devices can be in the same LAN, what kind of rounting technology can route the ip packet?
3. To route the traffic to the other LAN through WAN(MPLS), is it 6to4 will need to be in place?
4. To access internet, it points to our PIX  instead of PE router(MPLS), so is it I will need to implement 6to4 as well(if ISP can only provide ipv4 public address)?
5. We are using Microsoft IAS for Wireless connection and network device access authentication. If we implement IPv6, will IAS support IPv6?
6. Will PIX support IPv6? will have many site2site vpn connection.
 
If anyone who has experiences in IPv6 implementation project, please let me know as well.
 
Many Thanks,
 
Edward