wget prefers IPv4 address over IPv6 one

[Dawid Gajownik]

Hi!

	Does anyone know why wget prefers IPv4 address over IPv6 one?

[gajownik@cyklop tmp]$ LANG=C wget 
ftp://ftp.heanet.ie/pub/fedora/linux/releases/8/Fedora/i386/iso/Fedora-8-i386-rescuecd.iso
--14:34:30-- 
ftp://ftp.heanet.ie/pub/fedora/linux/releases/8/Fedora/i386/iso/Fedora-8-i386-rescuecd.iso
            => `Fedora-8-i386-rescuecd.iso'
Resolving ftp.heanet.ie... 193.1.193.64, 2001:770:18:aa40::c101:c140
Connecting to ftp.heanet.ie|193.1.193.64|:21... connected.

[snip]

What do you think about adding to the default /etc/wgetrc file this 
statement:

prefer-family = IPv6

Regards,
	Dawid

-- 

   ^_*

[John Summerfield]

Dawid Gajownik wrote:
>  Hi!
>  
>      Does anyone know why wget prefers IPv4 address over IPv6 one? 
Perhaps:
08:03 [summer@numbat ~]$ telnet 2001:770:18:aa40::c101:c140 21
Trying 2001:770:18:aa40::c101:c140...
telnet: connect to address 2001:770:18:aa40::c101:c140: Network is 
unreachable
telnet: Unable to connect to remote host: Network is unreachable

perhaps because it is less likely to work?

Here's another client:
08:07 [summer@numbat ~]$ lftp -d 2001:770:18:aa40::c101:c140
lftp 2001:770:18:aa40::c101:c140:~> dir
---- Connecting to 2001:770:18:aa40::c101:c140 
(2001:770:18:aa40::c101:c140) port 21
connect(control_sock): Network is unreachable
---- Closing control socket
---- Connecting to 2001:770:18:aa40::c101:c140 
(2001:770:18:aa40::c101:c140) port 21
connect(control_sock): Network is unreachable
---- Closing control socket
---- Connecting to 2001:770:18:aa40::c101:c140 
(2001:770:18:aa40::c101:c140) port 21
connect(control_sock): Network is unreachable
---- Closing control socket
`ls' at 0 [Delaying before reconnect: 58]

>  
>  [gajownik@cyklop tmp]$ LANG=C wget 
>
> ftp://ftp.heanet.ie/pub/fedora/linux/releases/8/Fedora/i386/iso/Fedora-8-i386-rescuecd.iso
>
>  
>  --14:34:30-- 
>
> ftp://ftp.heanet.ie/pub/fedora/linux/releases/8/Fedora/i386/iso/Fedora-8-i386-rescuecd.iso
>
>  
>             => `Fedora-8-i386-rescuecd.iso'
>  Resolving ftp.heanet.ie... 193.1.193.64, 2001:770:18:aa40::c101:c140
>  Connecting to ftp.heanet.ie|193.1.193.64|:21... connected.
>  
>  [snip]
>  
>  What do you think about adding to the default /etc/wgetrc file this 
>  statement:
>  
>  prefer-family = IPv6
>   
Not much, but feel free to try it.

>  Regards,
>      Dawid
>   

-- 

Cheers
John

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[Dawid Gajownik]

Dnia 12/17/2007 12:09 AM, Użytkownik John Summerfield napisał:
>  Perhaps:
>  08:03 [summer@numbat ~]$ telnet 2001:770:18:aa40::c101:c140 21
>  Trying 2001:770:18:aa40::c101:c140...
>  telnet: connect to address 2001:770:18:aa40::c101:c140: Network is 
>  unreachable
>  telnet: Unable to connect to remote host: Network is unreachable 
What show `traceroute6 2001:770:18:aa40::c101:c140' command? It works 
here without a problem:

[gajownik@cyklop tmp]$ LANG=C wget 
ftp://[2001:770:18:aa40::c101:c140]/pub/fedora/linux/releases/8/Fedora/i386/iso/Fedora-8-i386-rescuecd.iso
--00:13:58-- 
ftp://[2001:770:18:aa40::c101:c140]/pub/fedora/linux/releases/8/Fedora/i386/iso/Fedora-8-i386-rescuecd.iso
            => `Fedora-8-i386-rescuecd.iso'
Connecting to 2001:770:18:aa40::c101:c140:21... connected.
Logging in as anonymous ... Logged in!
==> SYST ... done.    ==> PWD ... done.
==> TYPE I ... done.  ==> CWD 
/pub/fedora/linux/releases/8/Fedora/i386/iso ... done.
==> EPSV ... done.    ==> RETR Fedora-8-i386-rescuecd.iso ... done.
Length: 107,833,344 (103M) (unauthoritative)

100%[===================================================================>] 
107,833,344    2.88M/s    ETA 00:00

00:14:22 (4.99 MB/s) - `Fedora-8-i386-rescuecd.iso' saved [107833344]

[gajownik@cyklop tmp]$

Regards,
	Dawid
-- 

   ^_*

[John Summerfield]

Dawid Gajownik wrote:
>  Dnia 12/17/2007 12:09 AM, UÅŒytkownik John Summerfield napisaÅ?:
> > Perhaps:
> > 08:03 [summer@numbat ~]$ telnet 2001:770:18:aa40::c101:c140 21
> > Trying 2001:770:18:aa40::c101:c140...
> > telnet: connect to address 2001:770:18:aa40::c101:c140: Network is 
> > unreachable
> > telnet: Unable to connect to remote host: Network is unreachable
>  
>  What show `traceroute6 2001:770:18:aa40::c101:c140' command? It works 
>  here without a problem:
>  
>  [gajownik@cyklop tmp]$ LANG=C wget 
>
> ftp://[2001:770:18:aa40::c101:c140]/pub/fedora/linux/releases/8/Fedora/i386/iso/Fedora-8-i386-rescuecd.iso
>
>  
>  --00:13:58-- 
>
> ftp://[2001:770:18:aa40::c101:c140]/pub/fedora/linux/releases/8/Fedora/i386/iso/Fedora-8-i386-rescuecd.iso
>
>  
>             => `Fedora-8-i386-rescuecd.iso'
>  Connecting to 2001:770:18:aa40::c101:c140:21... connected.
>  Logging in as anonymous ... Logged in!
>  ==> SYST ... done.    ==> PWD ... done.
>  ==> TYPE I ... done.  ==> CWD 
>  /pub/fedora/linux/releases/8/Fedora/i386/iso ... done.
>  ==> EPSV ... done.    ==> RETR Fedora-8-i386-rescuecd.iso ... done.
>  Length: 107,833,344 (103M) (unauthoritative)
>  
>  100%[===================================================================>] 
>  107,833,344    2.88M/s    ETA 00:00
>  
>  00:14:22 (4.99 MB/s) - `Fedora-8-i386-rescuecd.iso' saved [107833344] 

Whether it works for you is irrelevant, wget has to work everywhere, 
including networks that aren't configured for IP6.

Since _I_ don't take special action to support IP6, probably it falls 
over at my Internet gateway where IP6 traffic has to be mapped into IP4 
and NAT.

I don't imagine I'm Pat Malone here.




-- 

Cheers
John

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[Andrew Farris]

John Summerfield wrote:
>  Whether it works for you is irrelevant, wget has to work everywhere,
>  including networks that aren't configured for IP6.
>  
>  Since _I_ don't take special action to support IP6, probably it falls
>  over at my Internet gateway where IP6 traffic has to be mapped into IP4
>  and NAT. 
If you don't have IPv6 configured then trying to ask it to use it is not going
to get far, wget does not have to work when you do that.  However, if you do
have IPv6 configured and have connectivity to outside IPv6 networks then it
seems silly for wget to choose IPv4 when its given addresses in both families as
viable DNS resolution, which was his complaint.

I think shrek is right Dawid, bugzilla it; transitioning to IPv6 should still be
a priority and all apps should choose to use it when given the choice to make
(and both are viable choices).

-- 
Andrew Farris <lordmorgul(a)gmail.com&gt; <ajfarris(a)gmail.com&gt;
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No one now has, and no one will ever again get, the big picture. - Daniel Geer
----                                                                       ----

[John Summerfield]

Andrew Farris wrote:
>  John Summerfield wrote:
> > Whether it works for you is irrelevant, wget has to work everywhere,
> > including networks that aren't configured for IP6.
> >
> > Since _I_ don't take special action to support IP6, probably it falls
> > over at my Internet gateway where IP6 traffic has to be mapped into IP4
> > and NAT.
>  
>  If you don't have IPv6 configured then trying to ask it to use it is not going
>  to get far, wget does not have to work when you do that.  However, if you do
>  have IPv6 configured and have connectivity to outside IPv6 networks then it
>  seems silly for wget to choose IPv4 when its given addresses in both families as
>  viable DNS resolution, which was his complaint. 
I'm suggesting that the existing code works with minimal fuss and bother.

I've not noticed any of the soho adsl routers supporting IP6, and until 
they do we're stuck with IP4 for everyone who wants to provide or enjoy 
public access.

>  I think shrek is right Dawid, bugzilla it; transitioning to IPv6
> should still be
>  a priority and all apps should choose to use it when given the choice to make
>  (and both are viable choices). 
Before doing that, I suggest checking other programs, ftp clients such 
as ftp and lftp, telnet to the ftp port, and anything else that comes to 
hand.

It might be that there's more than wget needs adaptation. It's also 
perfectly possible the folk working on wget don't actually have an 
IP6-capable network.





-- 

Cheers
John

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[Dawid Gajownik]

Dnia 12/17/2007 12:55 AM, Użytkownik John Summerfield napisał:
>  Whether it works for you is irrelevant, wget has to work everywhere,
>
>  including networks that aren't configured for IP6. 
Sure, making wget broken on IPv4-only host is out of a question :) 
Before I wrote my first mail I've tested `prefer-family = IPv6' option 
on such a system (only link-local address on the network interface):

[y4kk0@X tmp]$ LANG=C wget 
http://ftp.heanet.ie/pub/fedora/linux/releases/8/Fedora/i386/iso/SHA1SUM
--18:25:22-- 
http://ftp.heanet.ie/pub/fedora/linux/releases/8/Fedora/i386/iso/SHA1SUM
Resolving ftp.heanet.ie... 2001:770:18:aa40::c101:c140, 193.1.193.64
Connecting to ftp.heanet.ie|2001:770:18:aa40::c101:c140|:80... failed: 
Network is unreachable.
Connecting to ftp.heanet.ie|193.1.193.64|:80... connected.

Regards,
	Dawid

-- 

   ^_*

[John Summerfield]

Dawid Gajownik wrote:
>  Dnia 12/17/2007 12:55 AM, UÅŒytkownik John Summerfield napisaÅ?:
> > Whether it works for you is irrelevant, wget has to work everywhere, 
> > including networks that aren't configured for IP6.
>  
>  Sure, making wget broken on IPv4-only host is out of a question :) 
>  Before I wrote my first mail I've tested `prefer-family = IPv6' option 
>  on such a system (only link-local address on the network interface):
>  
>  [y4kk0@X tmp]$ LANG=C wget 
>  http://ftp.heanet.ie/pub/fedora/linux/releases/8/Fedora/i386/iso/SHA1SUM
>  --18:25:22-- 
>  http://ftp.heanet.ie/pub/fedora/linux/releases/8/Fedora/i386/iso/SHA1SUM
>  Resolving ftp.heanet.ie... 2001:770:18:aa40::c101:c140, 193.1.193.64
>  Connecting to ftp.heanet.ie|2001:770:18:aa40::c101:c140|:80... failed: 
>  Network is unreachable.
>  Connecting to ftp.heanet.ie|193.1.193.64|:80... connected. 
and other ftp clients?


-- 

Cheers
John

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[Dawid Gajownik]

Dnia 12/17/2007 09:02 PM, Użytkownik John Summerfield napisał:
>  and other ftp clients? 
I checked so far curl, lftp, ftp, gftp and telnet to port 21 and they 
work as expected - they try to connect first using IPv6 address.

Regards,
	Dawid

-- 

   ^_*

Dawid Gajownik schrieb:
>  Hi!
>
>      Does anyone know why wget prefers IPv4 address over IPv6 one? 
you can try
$ wget -6 ftp://ftp.heanet.ie/...


http://www.gnu.org/software/wget/manual/wget.pdf
prefer family = IPv4/IPv6/none
            When given a choice of several addresses, connect to the
addresses with speci-
            fied address family first. IPv4 addresses are preferred by
default. The same as
            ‘--prefer-family’, which see for a detailed discussion of
why this is useful.

>  [gajownik@cyklop tmp]$ LANG=C wget
>
> ftp://ftp.heanet.ie/pub/fedora/linux/releases/8/Fedora/i386/iso/Fedora-8-i386-rescuecd.iso
>
>  --14:34:30--
>
> ftp://ftp.heanet.ie/pub/fedora/linux/releases/8/Fedora/i386/iso/Fedora-8-i386-rescuecd.iso
>
>             => `Fedora-8-i386-rescuecd.iso'
>  Resolving ftp.heanet.ie... 193.1.193.64, 2001:770:18:aa40::c101:c140
>  Connecting to ftp.heanet.ie|193.1.193.64|:21... connected.
>
>  [snip]
>
>  What do you think about adding to the default /etc/wgetrc file this
>  statement:
>
>  prefer-family = IPv6 
bugzilla ?

-- 
shrek-m

[Dawid Gajownik]

Dnia 12/17/2007 12:38 AM, Użytkownik shrek-m(a)gmx.de napisał:
> > What do you think about adding to the default /etc/wgetrc file
> this
> > statement:
> >
> > prefer-family = IPv6
>  
>  bugzilla ? 
Well, I just wanted to ask first about any issues that such a change in 
the default behavior could make (fedora-test-list has broader audience 
than bugzilla ;) ).

https://bugzilla.redhat.com/show_bug.cgi?id=425994

Regards,
	Dawid
-- 

   ^_*