6to4 question: IPv6 ping and tracert ok, browser won't load site

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freitasm

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#64826 23-Jul-2010 15:45

I have a question about 6to4 that's making things... Interesting here.

I never thought of testing it on my current laptop, because I already have a tunnel installed (Gogo), but was surprised last week to open a new Alienware and on connecting it to my network 6to4 was working out of the box.

Access to Geekzone was showing the Geekzone IPv6 logo, and http://ipv6.geekzone.co.nz (a test page that shows your IPv6 address, only accessible through IPv6) was fine with the browsers (IE8 and Chrome).

Today I decided to test this on a virtual machine, and it didn't open the page. I then fired up the Alienware machine and it didn't work either - it certainly worked fine last week.

Currently from a command prompt I have nslookup, ping -6 and tracert -6 working fine (listing below). If I enter http://ipv6.geekzone.co.nz in the address bar though the browsers won't load the page. But... if I add the IPv6 address to my hosts file the page loads fine.

Unfortunately I don't have a tracert -6 from last week when it just worked, but here is the output of nslookup, ping -6 and tracert -6 from the virtual machine (similar to the Alienware):

Server: srp521w
Address: 192.168.2.1

Name:    ipv6.geekzone.co.nz
Address: 2405:6000:f:100::1:2

Pinging ipv6.geekzone.co.nz [2405:6000:f:100::1:2] with 32 bytes of data:
Reply from 2405:6000:f:100::1:2: time=777ms
Reply from 2405:6000:f:100::1:2: time=307ms
Reply from 2405:6000:f:100::1:2: time=293ms
Reply from 2405:6000:f:100::1:2: time=289ms

Ping statistics for 2405:6000:f:100::1:2:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 289ms, Maximum = 777ms, Average = 416ms

Tracing route to ipv6.geekzone.co.nz [2405:6000:f:100::1:2]
over a maximum of 30 hops:

1   172 ms   169 ms   170 ms 6to4.pao1.he.net [2001:470:0:13b::2]
2   162 ms   161 ms   160 ms gige-g4-16.core1.pao1.he.net [2001:470:0:13b::1]
3   160 ms   168 ms   160 ms paix.bdr01.sjc01.ca.vocusconnect.net [2001:504:d::86]
4   161 ms   171 ms   162 ms 2402:7800:100:1::15
5   292 ms   288 ms   289 ms 2402:7800:100:1::1a
6   289 ms   292 ms   288 ms ten-0-1-0-60.bdr01.akl02.akl.VOCUS.net.au [2402:7800:110:1::16]
7   292 ms   287 ms   289 ms as4770.cust.bdr01.akl02.akl.VOCUS.net.au [2402:7800:110:50d::3]
8   289 ms   320 ms   294 ms 2405:6000:1:d::1
9   289 ms   289 ms   289 ms 2405:6000:1:1::2
10   293 ms   298 ms   297 ms 2405:6000:1:6::2
11   289 ms   294 ms   288 ms 2405:6000:1:1d::3
12   290 ms   288 ms   289 ms 2405:6000:f:100::1:2

Trace complete.

The "srp521w" in the nslookup is my router (Cisco SRP521W).

Any ideas why it's possible to ping, tracert but not open the page unless the address is in the hosts file?

Chippo

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#355434 23-Jul-2010 16:15

This may be because you don't have any IPv6 DNS servers configured. Windows (Or your browser?) isn't requesting AAAA records unless no A record exists. Would be interesting to see if Firefox/Chrome/IE made any difference.

For you, you could probably test by going to ipv6.geekzone.co.nz. If you have a 6to4 tunnel, this should work for you. Adding IPv6 DNS Servers manually may force windows to attempt an AAAA lookup first.

Love the trace. 6to4 connects you to the closest 6to4 gateway. It seems that on TelstraClear, your nearest gateway is at HE in the USA.

You've also reminded me: I must update APNIC to enable our IPv6 reverse DNS.

I work for a global Data Protection Software company - But my opinions are my own.

freitasm

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#355439 23-Jul-2010 16:21

Chippo: This may be because you don't have any IPv6 DNS servers configured. Windows (Or your browser?) isn't requesting AAAA records unless no A record exists. Would be interesting to see if Firefox/Chrome/IE made any difference.

The router is the default IPv6 DNS and it's returning an address (nslookup ipv6.geekzone.co.nz returns the correct address). The router's DNS is TelstraClear Clear DNS, which is now returning AAAA records - otherwise I wouldn't have nslookup, ping and tracert resolution.

So the question is really why the browser is not resolving? Or is it possible there's a conflict between the Teredo interface? Here is the ipconfig for the virtual machine:

Windows IP Configuration

   Host Name . . . . . . . . . . . . : WIN-KH9TNQA1H15
   Primary Dns Suffix . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix . :
   Description . . . . . . . . . . . : Intel(R) PRO/1000 MT Network Connection
   Physical Address. . . . . . . . . : 00-0C-29-4F-ED-A3
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::2018:4b0b:2b25:34fc%11(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.2.5(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Friday, July 23, 2010 2:41:17 PM
   Lease Expires . . . . . . . . . . : Saturday, July 24, 2010 2:41:17 PM
   Default Gateway . . . . . . . . . : 192.168.2.1
   DHCP Server . . . . . . . . . . . : 192.168.2.1
   DHCPv6 IAID . . . . . . . . . . . : 234884137
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-13-5D-48-7F-00-0C-29-4F-ED-A3
   DNS Servers . . . . . . . . . . . : 192.168.2.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.{AF2ADEDD-786E-4A5B-AFA7-FC1F422F6E63}:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

   Connection-specific DNS Suffix . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:387a:1ff7:349e:26c(Preferred)
   Link-local IPv6 Address . . . . . : fe80::387a:1ff7:349e:26c%13(Preferred)
   Default Gateway . . . . . . . . . : ::
   NetBIOS over Tcpip. . . . . . . . : Disabled

kyhwana2

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#355465 23-Jul-2010 17:03

I don't know about IE, or if this is still true with firefox. But I think firefox does/used to disable ipv6 by default?

Check about:config for ipv6. There's a variable that says to disable ipv6. Make sure it's false, etc.

webwat

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#355664 24-Jul-2010 02:56

Try to telnet to port 80 on ipv6.geekzone.co.nz or a text browser like Lynx? You dont have a web proxy in the mix anywhere?

http://msdn.microsoft.com/en-us/library/ms740593(VS.85).aspx

Time to find a new industry!

PenultimateHop

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#355671 24-Jul-2010 04:30

You don't appear to have a local 6to4 interface on the host itself; so I assume your router should be providing a local IPv6 subnet via SLAAC or DHCPv6 -- but it isn't, as you can see you only have a link-local address on your Ethernet interface.

Why your traceroute and ping are working I don't know - but there's definitely a networking issue on the PC itself that is stopping a) either 6to4 coming up (this will only work if the host has a public non-NAT IP), b) your PC being assigned an IPv6 address by your router if it is providing 6to4.

Note there are also a whole bunch of cases where Windows will happily select IPv4 in preference to IPv6 if both A and AAAA records are returned, due to an additional address preference table for IPv4 and IPv6.

raab

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#356127 25-Jul-2010 17:52

To set ipv6 as preference do the following

1. Start -> Run -> cmd -> netsh -> interface ipv6

2. set prefix ::1/128 50 0
set prefix ::/0 40 1
set prefix 2002::/16 30 1
set prefix ::/96 20 3
set prefix ::ffff:0/96 10 4
set prefix 2001::/32 5 5

To set ipv4 as preference
set prefix ::1/128 50 0
set prefix ::/0 40 1
set prefix 2002::/16 30 2
set prefix ::/96 20 3
set prefix ::ffff:0/96 10 4
set prefix 2001::/32 5 5

Shame about the routing on Telecom though

Tracing route to geekzone.co.nz [2405:6000:f:100::1:2]
over a maximum of 30 hops:

  1 * * * Request timed out.
  2 143 ms 143 ms 145 ms 2002:c058:6301::1
  3 144 ms 147 ms 149 ms gige-g4-12.core1.lax1.he.net [2001:470:0:14e::1]

  4 144 ms 144 ms 144 ms 10gigabitethernet1-3.core1.lax2.he.net [2001:470
:0:72::2]
  5 589 ms 589 ms 589 ms ge-1-3-2-140.bdr01.sjc01.nsw.VOCUS.net.au [2402:
7800:0:1::b9]
  6 590 ms 592 ms 589 ms 2402:7800:0:1::8a
  7 590 ms 591 ms 590 ms ten-0-1-0-60.bdr01.akl02.akl.VOCUS.net.au [2402:
7800:110:1::16]
  8 590 ms 590 ms 592 ms as4770.cust.bdr01.akl02.akl.VOCUS.net.au [2402:7
800:110:50d::3]
  9 591 ms 591 ms 592 ms 2405:6000:1:d::1
10 590 ms 591 ms 594 ms 2405:6000:1:1::2
11 592 ms 590 ms 590 ms 2405:6000:1:6::2
12 591 ms 590 ms 590 ms 2405:6000:1:1d::3
13 590 ms 591 ms 590 ms 2405:6000:f:100::1:2

freitasm

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#356134 25-Jul-2010 18:06

Thanks, but it doesn't solve the problem.

To be clear: I can use "nslookup ipv6.geekzone.co.nz", "ping -6 ipv6.geekzone.co.nz" and "tracert -6 ipv6.geekzone.co.nz" and the IPv6 address correctly resolves, both the ping and tracert work fine.

Opening the address on the browser though doesn't work, unless I explicitly list the address in the hosts file.

How can I test to be sure it's not the TelstraClear transparent proxy not being... "transparent"?

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

raab

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#356136 25-Jul-2010 18:12

My problem was that browsing to a website with a AAAA record would just default to the A record unless I added the ipv6 address to my hosts file.

Thought yours was the same issue, my bad

freitasm

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#356137 25-Jul-2010 18:15

raab: My problem was that browsing to a website with a AAAA record would just default to the A record unless I added the ipv6 address to my hosts file.

Thought yours was the same issue, my bad

Yes, that's the same issue... www.geekzone.co.nz has both A and AAAA records. ipv6.geekzone.co.nz has only AAAA records. Browsing to www.geekzone.co.nz shows the IPv4 connection, browsing to ipv6.geekzone.co.nz fails.

The link above to an article on using IE with IPv6 address clearly says I need an IPv6 address, not only link-local. PenultimateHop is correct then, there's something strange here.

I might clear the router DHCP table, restart it and see how it goes...

As I said, strange it worked before with the Alienware and this week it stopped working.

raab

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#356155 25-Jul-2010 19:19

Looks like an issue with 6to4, either with the router or your clients

This is what my ipconfig looks like

C:\Users\raab>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : alpha
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Marvell Yukon 88E8056 PCI-E Gigabit Ether
net Controller
Physical Address. . . . . . . . . : 00-26-18-92-70-41
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2002:7def:7653:1:c2c:5650:5a75:e651(Prefe
rred)
Temporary IPv6 Address. . . . . . : 2002:7def:7653:1:59eb:3c94:ec9b:bc23(Pref
erred)
Link-local IPv6 Address . . . . . : fe80::c2c:5650:5a75:e651%11(Preferred)
IPv4 Address. . . . . . . . . . . : 172.16.16.2(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : fe80::6a7f:74ff:fe9f:889a%11
172.16.16.1
DNS Servers . . . . . . . . . . . : 172.16.16.1
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.{7FB09BD3-9D35-412C-B0A0-839732EB7075}:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 11:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2001:0:cf2e:3096:3459:1a7e:8210:89ac(Pref
erred)
Link-local IPv6 Address . . . . . : fe80::3459:1a7e:8210:89ac%14(Preferred)
Default Gateway . . . . . . . . . :
NetBIOS over Tcpip. . . . . . . . : Disabled

nwardbraintrust

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Wannabe Geek

#357376 27-Jul-2010 20:56

Hi guys.

Craig Whitmore has asked me to post here in response to some of this.

Freitasm, your interface list has your only IPv6 connectivity via Teredo. MS Windows, when only presented with Teredo connectivity, will not ask for AAAA in DNS queries - if you have Teredo only connectivity, the only time it's going to be used is with some kind of non-DNS protocol giving your apps addresses to use. Bittorrent is by far the biggest example.

Even if you did get an AAAA response to a DNS query, the prefix policy table would prefer IPv4 over IPv6, because IPv4 is preferred to IPv6 when going between 6to4, Teredo, or native. If you were on a native IPv6 address, talking to a native host, then you would do fine.

If your web server was on a 6to4 address, and your client was on a 6to4 address, connectivity over IPv6/6to4 would take precedence over IPv4.

I can't recall the default prefix policy table in Windows, but from memory if your web server was on a Teredo address, and the client was a Teredo client, even though you were sticking within Teredo it would still prefer IPv4. I believe that was one of the implementation conditions put on MS for approving Teredo through the IETF process.

Does that answer your question?

I don't entirely understand what you are talking about with gogo and some new alien with 6to4, can you explain how your network is set up?

Also, who is Penultimatehop IRL? Cute name :-)

freitasm

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#416622 13-Dec-2010 16:56

Opening up this again... I've noticed one interesting thing here though: Windows XP boxes have IPv6 connectivity with nothing added/configured. I can ping ipv6.google.com for example and the browser happily opens the page. My Windows 7 boxes can't do it - they still resolve ok but that's all.

Windows XP is getting IPv6 connectivity throgh a Teredo interface.

I see I have an IP address on my Windows 7 Teredo interface. So the question is how we get this Teredo interface priority up?

nwardbraintrust

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#416772 13-Dec-2010 21:52

Windows should ask for AAAA records only if non-Teredo IPv6 connectivity is active (ie. 6to4, ISATAP, native).
I believe this is true of all versions of Windows.

Perhaps your browser is doing something funny?

Anyway, the preferences you talk about re-arranging are the prefix policy/address selection table. Have a read of RFC3848.

freitasm

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#416780 13-Dec-2010 22:03

Thanks will check the RFC... No, not only the browser. name resolution works, but nothing else - ping, ftp, http.

Interesting everything works fine on Windows XP but won't work on Windows 7...