Carrier detection for network interfaces

Carrier detection for network interfaces

[Martin Schlemmer]

Hi

Is there any proper way to detect a carrier signal with network
interfaces ?  I have recently come across a problem where we tried
to do with with checking for 'RUNNING', which do not work for all
drivers, as well as mii-tool that fails in some cases.


Thanks,

--
Martin Schlemmer

Re: Carrier detection for network interfaces

[Jeff Garzik]

Martin Schlemmer wrote:
> Is there any proper way to detect a carrier signal with network
> interfaces ?  I have recently come across a problem where we tried
> to do with with checking for 'RUNNING', which do not work for all
> drivers, as well as mii-tool that fails in some cases.


What kernel version?

In 2.6 you have linkwatch.  In 2.4 and 2.6, you have ETHTOOL_GLINK, and 
mii-tool.

	Jeff

Re: Carrier detection for network interfaces

[Martin Schlemmer]

On Sat, 2003-11-15 at 18:22, Jeff Garzik wrote:
> Martin Schlemmer wrote:
> > Is there any proper way to detect a carrier signal with network
> > interfaces ?  I have recently come across a problem where we tried
> > to do with with checking for 'RUNNING', which do not work for all
> > drivers, as well as mii-tool that fails in some cases.
> 
> 
> What kernel version?
> 
> In 2.6 you have linkwatch.  In 2.4 and 2.6, you have ETHTOOL_GLINK, and 
> mii-tool.
> 

Anything more shell accessible (sysfs/proc) ?


Thanks,

-- 
Martin Schlemmer

Re: Carrier detection for network interfaces

[Jeff Garzik]

Martin Schlemmer wrote:
> On Sat, 2003-11-15 at 18:22, Jeff Garzik wrote:
> 
>>Martin Schlemmer wrote:
>>
>>>Is there any proper way to detect a carrier signal with network
>>>interfaces ?  I have recently come across a problem where we tried
>>>to do with with checking for 'RUNNING', which do not work for all
>>>drivers, as well as mii-tool that fails in some cases.
>>
>>
>>What kernel version?
>>
>>In 2.6 you have linkwatch.  In 2.4 and 2.6, you have ETHTOOL_GLINK, and 
>>mii-tool.
>>
> 
> 
> Anything more shell accessible (sysfs/proc) ?


ethtool is shell accessible.

	Jeff

Re: Carrier detection for network interfaces

[Martin Schlemmer]

On Sat, 2003-11-15 at 22:40, Jeff Garzik wrote:
> Martin Schlemmer wrote:
> > On Sat, 2003-11-15 at 18:22, Jeff Garzik wrote:
> > 
> >>Martin Schlemmer wrote:
> >>
> >>>Is there any proper way to detect a carrier signal with network
> >>>interfaces ?  I have recently come across a problem where we tried
> >>>to do with with checking for 'RUNNING', which do not work for all
> >>>drivers, as well as mii-tool that fails in some cases.
> >>
> >>
> >>What kernel version?
> >>
> >>In 2.6 you have linkwatch.  In 2.4 and 2.6, you have ETHTOOL_GLINK, and 
> >>mii-tool.
> >>
> > 
> > 
> > Anything more shell accessible (sysfs/proc) ?
> 
> 
> ethtool is shell accessible.
> 

Yep, thanks.  Was just wondering if there was a way
that did not depend on additional tools beyond cat,
sed, grep, etc.


Thanks,

-- 
Martin Schlemmer

Re: Carrier detection for network interfaces

[Ben Greear]

Jeff Garzik wrote:
> Martin Schlemmer wrote:
> 
>> Is there any proper way to detect a carrier signal with network
>> interfaces ?  I have recently come across a problem where we tried
>> to do with with checking for 'RUNNING', which do not work for all
>> drivers, as well as mii-tool that fails in some cases.
> 
> 
> 
> What kernel version?
> 
> In 2.6 you have linkwatch.  In 2.4 and 2.6, you have ETHTOOL_GLINK, and 
> mii-tool.

One thing to watch for, lots of drivers will not detect link
if the interface itself is not configured to be running (UP).
You can configure it up without an IP address of course...

Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com

Re: Carrier detection for network interfaces

[Matthias Andree]

On Sat, 15 Nov 2003, Jeff Garzik wrote:

> What kernel version?
> 
> In 2.6 you have linkwatch.  In 2.4 and 2.6, you have ETHTOOL_GLINK, and 
> mii-tool.

Whatever linkwatch is (can't find it with Google and freshmeat quickly).

For 3c59x, neither mii-tool nor ethtool work with 2.6, only mii-diag
will do.

-- 
Matthias Andree

Encrypt your mail: my GnuPG key ID is 0x052E7D95

Re: Carrier detection for network interfaces

[Jeff Garzik]

Matthias Andree wrote:
> Whatever linkwatch is (can't find it with Google and freshmeat quickly).

Using netlink for link notification.


> For 3c59x, neither mii-tool nor ethtool work with 2.6, only mii-diag
> will do.


You need an updated mii-tool.

	Jeff