Networking problem

[JD]

On 05/17/11 04:25, JB wrote:
> Tom H<tomh0665<at>  gmail.com>  writes:
>
>> ...
>>> Let's try a ping from Fedora to Powerbook.
>>>
>>> snip
>>>
>>> But, the situation is curious, because we have ping's IPv4-format packet with
>>> FROM IPv4 address and TO IPv4 address going out thru IPv6-type interface
>> If you're referring to "192.168.1.254 0:1d:5a:c8:91:c1" as "FROM IPv4
>> address and TO IPv4 address going out thru IPv6-type interface" then
>> no. "0:1d:5a:c8:91:c1" is the MAC address of "192.168.1.254".
> No, I was referring to Fedora-to-Powerbook comm, but from the point of view of
> Fedora machine, in that paragraph:
>> Let's try a ping from Fedora to Powerbook.
>> ...
> When I mentioned IPv6 in context of Fedora-to-Powerbook comm, I meant this
> output.
>
> On Fedora Machine:
> # /sbin/ifconfig
> ...
> wlan0     Link encap:Ethernet  HWaddr 00:34:56:00:03:43
>             inet6 addr: fe80::234:56ff:fe00:343/64 Scope:Link
>             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>            ...
> wlan0:0   Link encap:Ethernet  HWaddr 00:34:56:00:03:43
>             inet addr:192.168.1.108  Bcast:192.168.1.255  Mask:255.255.255.0
>             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>
> For wlan0, this line shows an IPv6 link-local address (valid within the local
> subnetwork !):
>             inet6 addr: fe80::234:56ff:fe00:343/64 Scope:Link
> It is UP and RUNNING, and so ready for communication on IPv6 and link layers.
>
> It is a valid IPv6 interface.
> The fact that IPv6 layer was disabled on the subnet (as JD clarified it later),
> does not change anything. Once again, the type of configured interface wlan0
> is of interest to me, that is IPv6-type.
>
> Because wlan0 (not wlan0:0) does not have an IPv4 address assigned, I became
> suspicious of what that means when wlan0 was utilized in Fedora's routing
> table:
>
> # /bin/netstat -rn
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags   MSS Window  irtt
> Iface
> ...
> 192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0
> wlan0
> ...
> 0.0.0.0         192.168.1.254   0.0.0.0         UG        0 0          0
> wlan0
>
> That was the reason I analyzed the IPv4 packet flow between Fedora and
> Powerbook with "curiosity" with regard to wlan (IPv6-type interface) and
> wlan0:0 (IPv4-type interface).
>
> I am still not 100% clear what the implication of it is, so I would welcome
> any authoritative comment(s) on this matter.
>
> JB
>
>
ifconfig always prints a ipv6 address for an interface.
TO see the IP address you specify <iface>:0