Networking problem

[JD]

On 05/19/11 17:41, Tom H wrote:
> 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?
>

I have no  /etc/sysconfig/network-scripts/ifcfg-wlan0:0

$ cat /etc/sysconfig/network-scripts/ifcfg-wlan0:
BOOTPROTO=none
DEVICE=wlan0:0
ESSID=Le_Crappie_Router
UUID=48a80359-5bb1-ccfe-d847-4b84b5dbea95
IPADDR=192.168.1.108
GATEWAY=192.168.1.254
NETMASK=255.255.255.0
RTS=2346
FRAG=2346
IPV6INIT=no
MODE=Managed
RATE=auto
TYPE=Wireless
USERCTL=yes
NM_CONTROLLED=no
PREFIX=24
ONPARENT=no

>> 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.
Yes. ifconfig always prints this even when ip6 is disabled.
>> 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.
>

It really IS disabled. Look at the contents of my ifcfg-wlan0 above.
It says

IPV6INIT=no

>> 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.