[arch-general] IPv6 causing wget/curl to hang for a long time?

[Oon-Ee Ng]

On Mon, Jun 6, 2011 at 1:37 PM, Jan Steffens <jan.steffens at gmail.com> wrote:
> On Sun, Jun 5, 2011 at 12:36 PM, Oon-Ee Ng <ngoonee.talk at gmail.com> wrote:
>> I use the following line to get my current external IP in conky.
>> Recently Its been hanging for ages before responding, so I tried it
>> out and it seems to try an ipv6 address first before timing out and
>> succeeding on the ipv4 address. I know I can just disable ipv6, but
>> since on June 8th (AFAICR) there's gonna be a large scale test of that
>> on the interwebz, probably a good thing to keep around. Any
>> suggestions what the problem could be? Is it simply a faulty DNS
>> server (I'm using my local ISP's DNS)?
>>
>>  wget -O -i icanhazip.com
>> --2011-06-05 18:28:04--  http://icanhazip.com/
>> Resolving icanhazip.com... 2001:470:1f10:d57:feed:beef:cafe:d00d, 50.56.84.181
>> Connecting to icanhazip.com|2001:470:1f10:d57:feed:beef:cafe:d00d|:80...
>> failed: Connection timed out.
>> Connecting to icanhazip.com|50.56.84.181|:80... connected.
>> HTTP request sent, awaiting response... 200 OK
>> Length: 16 [text/plain]
>> Saving to: “-i”
>>
>> 100%[====================================================================================================================>]
>> 16          --.-K/s   in 0s
>>
>
> For it to even try connecting to IPv6 addresses, your computer would
> have to have routes set up for them. Now, the question is where do
> these routes come from?
>
> If they're added by autoconfiguration, there's something in your
> network advertising itself as a IPv6 router, but it's not actually
> functional. That's where the problem lies, then.
>
That seems consistent with what I'm experiencing, this does not happen
in my university. I get the following:-

ngoonee at ngoonee-laptop ~ % wget -O - icanhazip.com
--2011-06-06 14:21:38--  http://icanhazip.com/
Resolving icanhazip.com... 50.56.84.181, 2001:470:1f10:d57:feed:beef:cafe:d00d
Connecting to icanhazip.com|50.56.84.181|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 14 [text/plain]
Saving to: “STDOUT”

 0% [
                                                   ] 0
--.-K/s              59.191.194.87
100%[====================================================================================================================>]
14          --.-K/s   in 0s

2011-06-06 14:21:39 (650 KB/s) - written to stdout [14/14]

So it looks like a problem with my ISP at home. Not surprising. Wonder
whether its worth even letting them know. Could it perhaps be
something set wrongly in my router? ping6 just hangs....