Networking problem

[Tom H]

On Tue, May 17, 2011 at 7:25 AM, JB <jb.1234abcd at gmail.com> wrote:
> Tom H <tomh0665 <at> gmail.com> writes:

>> 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:
>
> 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.

Thanks for pointing to this wlan0/wlan0:0 business. I'd noticed it
earlier, meant to ask about it, and then completely forgot about it.

To the OP: Do you have a "/etc/sysconfig/network-scripts/ifcfg-wlan0"
and a "/etc/sysconfig/network-scripts/ifcfg-wlan0:0"? What are their
contents?


> It is a valid IPv6 interface.

It's valid but it isn't routable. It's the equivalent of an ipv4
169.254.x.y address.


> 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.

Since wlan0:0 has a ipv6 address, ipv6 must not be disabled.


> 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

Good point.


> I am still not 100% clear what the implication of it is, so I would welcome
> any authoritative comment(s) on this matter.

Me too.