drivers/net/usb/asix - Re: WS-UL220G USB 2.0 Gigabit Ethernet Adapter in Dell Inspiron 700m laptop

[David Curtis]

On Fri, 10 Jul 2009 15:09:21 -0700
Smoot Carl-Mitchell <smoot at tic.com> wrote:

> On Fri, 2009-07-10 at 17:02 -0400, David Curtis wrote:
> 
> > > # route -n
> > > Kernel IP routing table
> > > Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
> > > 172.22.22.0     0.0.0.0         255.255.255.0   U     29     0        0 eth2
> > > 169.254.0.0     0.0.0.0         255.255.0.0     U     29     0        0 eth2
> > > 0.0.0.0         172.22.22.2     0.0.0.0         UG    0      0        0 eth2
> > 
> > A metric of 29 is definitely an indication something is wrong, I
> > believe that anything over 16 (hops) is considered unusable. And
> > anyway the metric for the network segment (172.22.22.0) you're on
> > should be 0. The unused default network (169.254.0.0) on my jaunty box
> > has a metric of 1000. Something is definitely setting supposedly
> > unused segments to 29. What's doing that? I dunno.  
> 
> Routing table metrics have nothing to do with Internet hop count or time
> to live.  I believe the default TTL on the Internet tis set to 64 these
> days.  Linux seems to set the default to this value.  Take a look
> at /proc/sys/net/ipv4/ip_default_ttl.

>From 'man route', 

"Metric - The 'distance' to the target (usually counted in hops). It is not used by recent kernels but may be needed by routing daemons"

My use of the word 'hop' was correct, I did not say anything about TTL, and I know full well that routing metrics and TTL have nothing to do with each other.  But as it says above, metrics are not in use by recent kernels, which makes the whole thing moot.


> 
> The metrics in the routing table are only are relative to other local
> routes.  The value is used to set routing preferences where there is
> more than a single path to a remote network.

Which is why I find the network segment the node is on, to have a metric of 29 and not 0, kinda strange.

> 
> With that said, I have no idea why the metric is set to 29, but it will
> not affect your routing.

Well as above, recent kernels don't use metrics. But I'll concede your point and change mine to: If something is setting the metric to 29, it could be affecting other things. (There, that should get my out of hot water.) :) 

Maybe the OP is using some type of routing package that might be getting confused by the local network segment being moved from eth0 to eth2. But I doubt that on a laptop.

-- 
David Curtis <dcurtis at uniserve.com>