VT IPv6 Test


Your address:
Server name: ipv6-test-nolisten6.cns.vt.edu:9080
Server address:


Full URLS shown below have both A and AAAA records. The IPv4 and IPv6 only alternatives have only A and AAAA records respectively. They can be used for testing connectivity over a particular protocol. Note that not all of the IPv6 addresses are expected to answer.

URL Description
http://ipv6-test.cns.vt.edu/ (IPv6 only) (IP only) Normal site with both IP and IPv6. The default config in most cases it to connect with IPv6 if it is available. If you have IPv6 and that doesn't happen, check your browser settings (network.dns.disableIPv6 in Firefox) and OS configuration.
http://ipv6-test-nolisten6.cns.vt.edu:9080/ (IPv6 only) (IP only) Service listening only on IP address. IPv6 port is open in firewall and should send TCP RST. This is what happens if there is a server that does not listen on IPv6. Clients should fall back to IPv4 immediately.
http://ipv6-test-nohost6.cns.vt.edu/ (IPv6 only) (IP only) IPv6 host that does not exist on a valid subnet.
http://ipv6-test-nosubnet6.cns.vt.edu/ (IPv6 only) (IP only) IPv6 subnet that does not exist on our network.
http://ipv6-test-iwf6.cns.vt.edu:9081/ (IPv6 only) (IP only) Service listening on IP only, IPv6 port silently drops TCP SYN.
h2. Web Server Configuration Notes
# iptables --list | grep 908
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:9080
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:9081

# ip6tables --list | grep 908
ACCEPT     tcp      anywhere             anywhere           tcp dpt:9080
# 9081 is closed

# Apache
# NameVirtualHost is expected to be Yes
# UseCanonicalName is expected to be No
<VirtualHost ipv6-test.cns.vt.edu:80>
    ServerAdmin ipv6-support@cns.vt.edu
    ServerName ipv6-test.cns.vt.edu
    #ServerAlias www.dummy-host.example.com
    #ErrorLog logs/dummy-host.example.com-error_log
    #CustomLog logs/dummy-host.example.com-access_log common

<VirtualHost ipv6-test-nolisten6.cns.ipv4.vt.edu:9080>
    # Bind only to v4 address.
    # V6 port should be open and send RST.
    ServerAdmin ipv6-support@cns.vt.edu
    ServerName ipv6-test-nolisten.cns.vt.edu

<VirtualHost ipv6-test-nohost6.cns.ipv4.vt.edu:80>
    # Bind only to v4 address.
    # V6 address not on any host but on this subnet
    ServerAdmin ipv6-support@cns.vt.edu
    ServerName ipv6-test-nohost6.cns.vt.edu

<VirtualHost ipv6-test-nosubnet6.cns.ipv4.vt.edu:80>
    # Bind only to v4 address.
    # V6 address on a subnet that does not exist
    ServerAdmin ipv6-support@cns.vt.edu
    ServerName ipv6-test-nosubnet6.cns.vt.edu

<VirtualHost ipv6-test-iwf6.cns.vt.edu:9081>
    # Bind only to v4 address.
    # V6 address blocked by firewall.
    ServerAdmin ipv6-support@cns.vt.edu
    ServerName ipv6-test-iwf6.cns.vt.edu