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* [gentoo-user] ipv6 problem with ping6
@ 2012-01-06 21:02 Grant Edwards
  2012-01-06 21:09 ` Michael Mol
  0 siblings, 1 reply; 6+ messages in thread
From: Grant Edwards @ 2012-01-06 21:02 UTC (permalink / raw
  To: gentoo-user

I've enabled ipv6 support in my kernel and it appears to be working on
the "lo" interface:

   # ip -6 addr show lo  
   
   1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 
       inet6 ::1/128 scope host 
          valid_lft forever preferred_lft forever
          
   # ping6 -c3 ::1
   
   PING ::1(::1) 56 data bytes
   64 bytes from ::1: icmp_seq=1 ttl=64 time=0.022 ms
   64 bytes from ::1: icmp_seq=2 ttl=64 time=0.021 ms
   64 bytes from ::1: icmp_seq=3 ttl=64 time=0.021 ms
   
   --- ::1 ping statistics ---
   3 packets transmitted, 3 received, 0% packet loss, time 1998ms
   rtt min/avg/max/mdev = 0.021/0.021/0.022/0.003 ms

And the other interfaces all have link-local addresses:

   # ip -6 addr show eth1
   3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
       inet6 fe80::216:17ff:fe84:a7b3/64 scope link 
          valid_lft forever preferred_lft forever
          
But I can't ping6 any of the "real" interfaces (or any external
address):

   # ping6 -c3 fe80::216:17ff:fe84:a7b3
   
   connect: Invalid argument

Why can I ping "lo" at ::1 and not "eth1" at fe80::216:17ff:fe84:a7b3?
   
I'm guessing there might other packages I have to re-emerge with the
ipv6 use flag. But, I do not want to rebuild everything capable of
supporting ipv6, since there are only a few selected programs that
I'll be using with ipv6.  I thought I might have to rebuild glibc, but
it doens't list ipv6 as one of it's use flags.

Any hints?

-- 
Grant Edwards               grant.b.edwards        Yow! I had a lease on an
                                  at               OEDIPUS COMPLEX back in
                              gmail.com            '81 ...




^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [gentoo-user] ipv6 problem with ping6
  2012-01-06 21:02 [gentoo-user] ipv6 problem with ping6 Grant Edwards
@ 2012-01-06 21:09 ` Michael Mol
  2012-01-06 21:20   ` Paul Hartman
                     ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Michael Mol @ 2012-01-06 21:09 UTC (permalink / raw
  To: gentoo-user

Grant Edwards wrote:
> I've enabled ipv6 support in my kernel and it appears to be working on
> the "lo" interface:
> 
>    # ip -6 addr show lo  
>    
>    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 
>        inet6 ::1/128 scope host 
>           valid_lft forever preferred_lft forever
>           
>    # ping6 -c3 ::1
>    
>    PING ::1(::1) 56 data bytes
>    64 bytes from ::1: icmp_seq=1 ttl=64 time=0.022 ms
>    64 bytes from ::1: icmp_seq=2 ttl=64 time=0.021 ms
>    64 bytes from ::1: icmp_seq=3 ttl=64 time=0.021 ms
>    
>    --- ::1 ping statistics ---
>    3 packets transmitted, 3 received, 0% packet loss, time 1998ms
>    rtt min/avg/max/mdev = 0.021/0.021/0.022/0.003 ms
> 
> And the other interfaces all have link-local addresses:
> 
>    # ip -6 addr show eth1
>    3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
>        inet6 fe80::216:17ff:fe84:a7b3/64 scope link 
>           valid_lft forever preferred_lft forever
>           
> But I can't ping6 any of the "real" interfaces (or any external
> address):
> 
>    # ping6 -c3 fe80::216:17ff:fe84:a7b3
>    
>    connect: Invalid argument
> 
> Why can I ping "lo" at ::1 and not "eth1" at fe80::216:17ff:fe84:a7b3?
>    
> I'm guessing there might other packages I have to re-emerge with the
> ipv6 use flag. But, I do not want to rebuild everything capable of
> supporting ipv6, since there are only a few selected programs that
> I'll be using with ipv6.  I thought I might have to rebuild glibc, but
> it doens't list ipv6 as one of it's use flags.
> 
> Any hints?
> 

ping6 -c3 fe80::216:17ff:fe84:a7b3%eth0

Link-local addresses are only valid at the link-level scope, and you
have to specify which link you're referring to. Global-scope addresses
don't have the same limitation.

Also, for fun, try this:
ping6 -c3 ff02::1%eth0




^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [gentoo-user] ipv6 problem with ping6
  2012-01-06 21:09 ` Michael Mol
@ 2012-01-06 21:20   ` Paul Hartman
  2012-01-06 21:27     ` Michael Mol
  2012-01-06 21:40   ` [gentoo-user] " Grant Edwards
  2012-01-06 21:51   ` Grant Edwards
  2 siblings, 1 reply; 6+ messages in thread
From: Paul Hartman @ 2012-01-06 21:20 UTC (permalink / raw
  To: gentoo-user

On Fri, Jan 6, 2012 at 3:09 PM, Michael Mol <mikemol@gmail.com> wrote:
> Grant Edwards wrote:
>> I've enabled ipv6 support in my kernel and it appears to be working on
>> the "lo" interface:
>>
>>    # ip -6 addr show lo
>>
>>    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436
>>        inet6 ::1/128 scope host
>>           valid_lft forever preferred_lft forever
>>
>>    # ping6 -c3 ::1
>>
>>    PING ::1(::1) 56 data bytes
>>    64 bytes from ::1: icmp_seq=1 ttl=64 time=0.022 ms
>>    64 bytes from ::1: icmp_seq=2 ttl=64 time=0.021 ms
>>    64 bytes from ::1: icmp_seq=3 ttl=64 time=0.021 ms
>>
>>    --- ::1 ping statistics ---
>>    3 packets transmitted, 3 received, 0% packet loss, time 1998ms
>>    rtt min/avg/max/mdev = 0.021/0.021/0.022/0.003 ms
>>
>> And the other interfaces all have link-local addresses:
>>
>>    # ip -6 addr show eth1
>>    3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
>>        inet6 fe80::216:17ff:fe84:a7b3/64 scope link
>>           valid_lft forever preferred_lft forever
>>
>> But I can't ping6 any of the "real" interfaces (or any external
>> address):
>>
>>    # ping6 -c3 fe80::216:17ff:fe84:a7b3
>>
>>    connect: Invalid argument
>>
>> Why can I ping "lo" at ::1 and not "eth1" at fe80::216:17ff:fe84:a7b3?
>>
>> I'm guessing there might other packages I have to re-emerge with the
>> ipv6 use flag. But, I do not want to rebuild everything capable of
>> supporting ipv6, since there are only a few selected programs that
>> I'll be using with ipv6.  I thought I might have to rebuild glibc, but
>> it doens't list ipv6 as one of it's use flags.
>>
>> Any hints?
>>
>
> ping6 -c3 fe80::216:17ff:fe84:a7b3%eth0
>
> Link-local addresses are only valid at the link-level scope, and you
> have to specify which link you're referring to. Global-scope addresses
> don't have the same limitation.

and to see the scope you can view the output of ifconfig, see
something in there like this next to each address:

scopeid 0x0<global>
scopeid 0x20<link>



^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [gentoo-user] ipv6 problem with ping6
  2012-01-06 21:20   ` Paul Hartman
@ 2012-01-06 21:27     ` Michael Mol
  0 siblings, 0 replies; 6+ messages in thread
From: Michael Mol @ 2012-01-06 21:27 UTC (permalink / raw
  To: gentoo-user

Paul Hartman wrote:
> On Fri, Jan 6, 2012 at 3:09 PM, Michael Mol <mikemol@gmail.com> wrote:
>> Grant Edwards wrote:
>>> I've enabled ipv6 support in my kernel and it appears to be working on
>>> the "lo" interface:
>>>
>>>    # ip -6 addr show lo
>>>
>>>    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436
>>>        inet6 ::1/128 scope host
>>>           valid_lft forever preferred_lft forever
>>>
>>>    # ping6 -c3 ::1
>>>
>>>    PING ::1(::1) 56 data bytes
>>>    64 bytes from ::1: icmp_seq=1 ttl=64 time=0.022 ms
>>>    64 bytes from ::1: icmp_seq=2 ttl=64 time=0.021 ms
>>>    64 bytes from ::1: icmp_seq=3 ttl=64 time=0.021 ms
>>>
>>>    --- ::1 ping statistics ---
>>>    3 packets transmitted, 3 received, 0% packet loss, time 1998ms
>>>    rtt min/avg/max/mdev = 0.021/0.021/0.022/0.003 ms
>>>
>>> And the other interfaces all have link-local addresses:
>>>
>>>    # ip -6 addr show eth1
>>>    3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
>>>        inet6 fe80::216:17ff:fe84:a7b3/64 scope link
>>>           valid_lft forever preferred_lft forever
>>>
>>> But I can't ping6 any of the "real" interfaces (or any external
>>> address):
>>>
>>>    # ping6 -c3 fe80::216:17ff:fe84:a7b3
>>>
>>>    connect: Invalid argument
>>>
>>> Why can I ping "lo" at ::1 and not "eth1" at fe80::216:17ff:fe84:a7b3?
>>>
>>> I'm guessing there might other packages I have to re-emerge with the
>>> ipv6 use flag. But, I do not want to rebuild everything capable of
>>> supporting ipv6, since there are only a few selected programs that
>>> I'll be using with ipv6.  I thought I might have to rebuild glibc, but
>>> it doens't list ipv6 as one of it's use flags.
>>>
>>> Any hints?
>>>
>>
>> ping6 -c3 fe80::216:17ff:fe84:a7b3%eth0
>>
>> Link-local addresses are only valid at the link-level scope, and you
>> have to specify which link you're referring to. Global-scope addresses
>> don't have the same limitation.
> 
> and to see the scope you can view the output of ifconfig, see
> something in there like this next to each address:
> 
> scopeid 0x0<global>
> scopeid 0x20<link>
> 

Likewise, if you use iproute2:

shortcircuit:0@prgmr2.rosettacode.org~
Fri Jan 06 09:24 PM
!502 #2 j0 ?0 $ ip -6 addr show eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
    inet6 2605:2700:0:3::4713:91bf/64 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::a800:ff:fe13:91bf/64 scope link
       valid_lft forever preferred_lft forever


The phrase "scope global" or "scope link" appears after each of my IPv6
addresses on that interface.




^ permalink raw reply	[flat|nested] 6+ messages in thread

* [gentoo-user] Re: ipv6 problem with ping6
  2012-01-06 21:09 ` Michael Mol
  2012-01-06 21:20   ` Paul Hartman
@ 2012-01-06 21:40   ` Grant Edwards
  2012-01-06 21:51   ` Grant Edwards
  2 siblings, 0 replies; 6+ messages in thread
From: Grant Edwards @ 2012-01-06 21:40 UTC (permalink / raw
  To: gentoo-user

On 2012-01-06, Michael Mol <mikemol@gmail.com> wrote:
> Grant Edwards wrote:
>> I've enabled ipv6 support in my kernel and it appears to be working on
>> the "lo" interface:
>> 
>>    # ip -6 addr show lo  
>>    
>>    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 
>>        inet6 ::1/128 scope host 
>>           valid_lft forever preferred_lft forever
>>           
>>    # ping6 -c3 ::1
>>    
>>    PING ::1(::1) 56 data bytes
>>    64 bytes from ::1: icmp_seq=1 ttl=64 time=0.022 ms
>>    64 bytes from ::1: icmp_seq=2 ttl=64 time=0.021 ms
>>    64 bytes from ::1: icmp_seq=3 ttl=64 time=0.021 ms
>>    
>>    --- ::1 ping statistics ---
>>    3 packets transmitted, 3 received, 0% packet loss, time 1998ms
>>    rtt min/avg/max/mdev = 0.021/0.021/0.022/0.003 ms
>> 
>> And the other interfaces all have link-local addresses:
>> 
>>    # ip -6 addr show eth1
>>    3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
>>        inet6 fe80::216:17ff:fe84:a7b3/64 scope link 
>>           valid_lft forever preferred_lft forever
>>           
>> But I can't ping6 any of the "real" interfaces (or any external
>> address):
>> 
>>    # ping6 -c3 fe80::216:17ff:fe84:a7b3
>>    
>>    connect: Invalid argument
>> 
>> Why can I ping "lo" at ::1 and not "eth1" at fe80::216:17ff:fe84:a7b3?
>>    
>> I'm guessing there might other packages I have to re-emerge with the
>> ipv6 use flag. But, I do not want to rebuild everything capable of
>> supporting ipv6, since there are only a few selected programs that
>> I'll be using with ipv6.  I thought I might have to rebuild glibc, but
>> it doens't list ipv6 as one of it's use flags.
>> 
>> Any hints?
>> 
>
> ping6 -c3 fe80::216:17ff:fe84:a7b3%eth0
>
> Link-local addresses are only valid at the link-level scope, and you
> have to specify which link you're referring to. Global-scope
> addresses don't have the same limitation.

Yup.  The other option is to use -I to specify the interface.

I missed that the first time I read through the man page because I was
expecting it to be "-i" (I guess that was tcpdump).

-- 
Grant Edwards               grant.b.edwards        Yow! DIDI ... is that a
                                  at               MARTIAN name, or, are we
                              gmail.com            in ISRAEL?




^ permalink raw reply	[flat|nested] 6+ messages in thread

* [gentoo-user] Re: ipv6 problem with ping6
  2012-01-06 21:09 ` Michael Mol
  2012-01-06 21:20   ` Paul Hartman
  2012-01-06 21:40   ` [gentoo-user] " Grant Edwards
@ 2012-01-06 21:51   ` Grant Edwards
  2 siblings, 0 replies; 6+ messages in thread
From: Grant Edwards @ 2012-01-06 21:51 UTC (permalink / raw
  To: gentoo-user

On 2012-01-06, Michael Mol <mikemol@gmail.com> wrote:

> ping6 -c3 fe80::216:17ff:fe84:a7b3%eth0
>
> Link-local addresses are only valid at the link-level scope, and you
> have to specify which link you're referring to.

OK, that makes sense when there are multiple non-loopback interfaces.
but it appears that even when there is only a single interface you
still have to explicitly specify which one of the one available
interfaces to use.

> Global-scope addresses don't have the same limitation.
>
> Also, for fun, try this:
> ping6 -c3 ff02::1%eth0

Cool.  There are more ipv6-capable machines on the LAN than I
expected...

-- 
Grant Edwards               grant.b.edwards        Yow! Half a mind is a
                                  at               terrible thing to waste!
                              gmail.com            




^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2012-01-06 21:54 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-01-06 21:02 [gentoo-user] ipv6 problem with ping6 Grant Edwards
2012-01-06 21:09 ` Michael Mol
2012-01-06 21:20   ` Paul Hartman
2012-01-06 21:27     ` Michael Mol
2012-01-06 21:40   ` [gentoo-user] " Grant Edwards
2012-01-06 21:51   ` Grant Edwards

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