I have CentOS 6 running kvm. IPv4 works perfectly works. But I am having some problem with ipv6, looks like its bridge routing problem but stuck.

here are my bridge detail:

bridge name bridge id STP enabled interfaces br0 8000.000af75613f2 no eth1
vnet1
br4 8000.000af75613f0 no eth0

ip -6 route shows :

unreachable ::/96 dev lo metric 1024 error -101 mtu 65536 advmss 65476
hoplimit 4294967295
unreachable ::ffff:0.0.0.0/96 dev lo metric 1024 error -101 mtu 65536
advmss 65476 hoplimit 4294967295
unreachable 2002:a00::/24 dev lo metric 1024 error -101 mtu 65536 advmss
65476 hoplimit 4294967295
unreachable 2002:7f00::/24 dev lo metric 1024 error -101 mtu 65536 advmss
65476 hoplimit 4294967295
unreachable 2002:a9fe::/32 dev lo metric 1024 error -101 mtu 65536 advmss
65476 hoplimit 4294967295
unreachable 2002:ac10::/28 dev lo metric 1024 error -101 mtu 65536 advmss
65476 hoplimit 4294967295
unreachable 2002:c0a8::/32 dev lo metric 1024 error -101 mtu 65536 advmss
65476 hoplimit 4294967295
unreachable 2002:e000::/19 dev lo metric 1024 error -101 mtu 65536 advmss
65476 hoplimit 4294967295
2a00:c88:4000:1431::/64 dev br0 proto kernel metric 256 mtu 1500 advmss
1440 hoplimit 4294967295
2a00:c88:4000:1650::/64 dev br4 proto kernel metric 256 mtu 1500 advmss
1440 hoplimit 4294967295
unreachable 3ffe:ffff::/32 dev lo metric 1024 error -101 mtu 65536 advmss
65476 hoplimit 4294967295
fe80::/64 dev vnet0 proto kernel metric 256 mtu 1500 advmss 1440
hoplimit 4294967295
fe80::/64 dev vnet1 proto kernel metric 256 mtu 1500 advmss 1440
hoplimit 4294967295
fe80::/64 dev vnet2 proto kernel metric 256 mtu 1500 advmss 1440
hoplimit 4294967295
fe80::/64 dev vnet3 proto kernel metric 256 mtu 1500 advmss 1440
hoplimit 4294967295
fe80::/64 dev eth0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit
4294967295
fe80::/64 dev eth1 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit
4294967295
fe80::/64 dev br0 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit
4294967295
fe80::/64 dev br4 proto kernel metric 256 mtu 1500 advmss 1440 hoplimit
4294967295
default via 2a11:c99:4111:110::11:211 dev br4 metric 1 mtu 1500 advmss
1440 hoplimit 4294967295

Then I added, /etc/sysconfig/network-script/ifcfg-br4
DEVICE=br4
TYPE=Bridge ONBOOT=yes BOOTPROTO=static IPADDR=ipv4address here NETMASK%5.255.255.0
DNS1=mydnsserver.org DELAY=0
NM_CONTROLLED=no IPV6INIT=yes IPV6_AUTOCONF=no
#IPV6_DEFROUTE=”yes”
IPV6_FAILURE_FATAL=yes IPV6ADDR*11:c99:4111:110::11:65/64
IPV6_DEFAULTGW= 2a11:c99:4111:110::11:211

I can ping the gateway from the kvm host but I cannot ping6 out from the kvm guest, also I cannot ping kvm guest from external host that is in ipv6
network.

I appreciate some guidance on this.