From: Stephen Hemminger <stephen@networkplumber.org>
To: Jeff Silverman <jeffsilverm@gmail.com>
Cc: netdev@vger.kernel.org
Subject: Re: I find one aspect of the ip link show command confusing and I'd like you to fix it, please
Date: Mon, 24 Apr 2017 08:54:07 -0700 [thread overview]
Message-ID: <20170424085407.2b9df529@xeon-e3> (raw)
In-Reply-To: <CAGu9dLLRVaiO-vHd_jzVuMM3O=sjLX_VOeu5n6-+eV6fEdhBug@mail.gmail.com>
On Sun, 23 Apr 2017 15:36:32 -0700
Jeff Silverman <jeffsilverm@gmail.com> wrote:
> People,
>
> When my NIC is up, but not connected, I see:
>
> root@jeff-desktop:~# ip link show enp3s0
> 2: enp3s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state
> DOWN mode DEFAULT group default qlen 1000
> link/ether 00:10:18:cc:9c:77 brd ff:ff:ff:ff:ff:ff
> root@jeff-desktop:~# ip link show enp3s0
>
> NO-CARRIER makes sense to me - if the wire is unplugged, then the NIC
> isn't seeing the humm at the beginning of each packet. That's clear.
> Note that even though my link isn't plugged in, ip still notes that
> it is up. That's great.
>
>
> But if I down my NIC, there is no indication that it is DOWN other
> than you can't see the UP flag. If somebody was new to linux, they
> would not see what's not there.
>
> 2: enp3s0: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN mode
> DEFAULT group default qlen 1000
> link/ether 00:10:18:cc:9c:77 brd ff:ff:ff:ff:ff:ff
>
>
> What I would like you to do is modify the ip command so that if the
> NIC has been downed by something, then it explicitly says DOWN.
>
> What would be really nice would be if you enumerated all of the flags
> that an interface can have, and note if the flag is set or cleared.
> But that's more than what I want with this message.
>
>
> Many thanks,
>
>
> Jeff
>
If you have a suggestion send a patch. The utility has shown the same
output since the earliest versions. Therefore the default output format
can't change since people do things like write scripts to parse it.
A more verbose output is possible but would have to be enabled by
a flag.
prev parent reply other threads:[~2017-04-24 15:54 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-23 22:36 I find one aspect of the ip link show command confusing and I'd like you to fix it, please Jeff Silverman
2017-04-24 15:54 ` Stephen Hemminger [this message]
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