Unique local vs global addressing for greenfield site?

[sean_evershed]

I have seen several different recommendations listed below when designing an IPv6 addressing scheme for internal network infrastructure.

Is the recommended approach to deploy global addresses internally?

Approach 1: Unique Local Addresses

Coming from an IPv4 background this makes sense to me being the equivalent to an RFC 1918 address.

Approach 2: Global Addresses

Purchase a global address block from your ISP or ARIN.

This approach however appears to have security implications since careful attention needs to be paid to your Internet facing firewall rules.

Approach 3: Combination of Unique Local and global addressing.

Thanks

Sean

[dominic.caron]

The goal of ULA is to allow network with no GA to run IPv6 internaly. If you connect to the internet, use Global addresses.