Ubuntu12.04 when the internal network ipv6 is good or bad, new users seek help

Ubuntu12.04 indicates that ipv6 on the internal network is good or bad. new users seek help-General Linux technology-Linux technology and application information. for details, refer to the following section. :~ $ Ifconfig
Eth0 Link encap: Ethernet HWaddr 00: 1f: 16: 31: 1f: 78
Inet addr: 180.201.10.58 Bcast: 180.201.11.255 Mask: 255.255.254.0
Inet6 addr: 2001: da8: 7000: 7008: 21f: 16ff: fe31: 1f78/64 Scope: Global
Inet6 addr: fec0: a: 21f: 16ff: fe31: 1f78/64 Scope: Site
Inet6 addr: 2002: b4c9: a93: a: 21f: 16ff: fe31: 1f78/64 Scope: Global
Inet6 addr: fe80: 21f: 16ff: fe31: 1f78/64 Scope: Link
Inet6 addr: 2001: da8: 7000: 7008: 85af: 4677: fb96: 1915/64 Scope: Global
Inet6 addr: fec0: a: 85af: 4677: fb96: 1915/64 Scope: Site
Inet6 addr: 2002: b4c9: a93: a: 85af: 4677: fb96: 1915/64 Scope: Global
Up broadcast running multicast mtu: 1500 Metric: 1
RX packets: 36660 errors: 0 dropped: 1 overruns: 0 frame: 0
TX packets: 6171 errors: 0 dropped: 0 overruns: 0 carrier: 1
Collisions: 0 fig: 1000
RX bytes: 8394836 (8.3 MB) TX bytes: 815668 (815.6 KB)
Interrupt: 45

Lo Link encap: Local Loopback
Inet addr: 127.0.0.1 Mask: 255.0.0.0
Inet6 addr: 1/128 Scope: Host
Up loopback running mtu: 16436 Metric: 1
RX packets: 657 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 657 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 txqueuelen: 0
RX bytes: 70789 (70.7 KB) TX bytes: 70789 (70.7 KB)
How can I ensure good or bad intranet ipv6 connections in the same dormitory? why should I pay attention to the probability ???