I just realized that upstream has support for showing addrgenmode already:

ip -d link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 promiscuity 0 addrgenmode eui64

As seen above, it is only being shown when you request link details.

The following commit was missing and a slightly adapted version of it was added:

commit ee0067a918e229cd0f3689364b4ce5eadbe3abdd
Author: Jiri Pirko <jiri>
Date:   Thu Jan 8 09:49:55 2015 +0100

    iplink: print out addrgenmode attribute
    
    addrgenmode is currently write only by ip. So display this information
    if provided by kernel as well.
    
    Signed-off-by: Jiri Pirko <jiri>

 ip/ipaddress.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

The following commit was included already:

commit ff7c20844049be836c10087cb2418b99ff36ca2b
Author: Jiri Pirko <jiri>
Date:   Fri Jul 11 21:11:46 2014 +0200

    iproute2: allow to ipv6 set address generation mode
    
    Signed-off-by: Jiri Pirko <jiri>

 ip/iplink.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

(In reply to Thomas Haller from comment #0)
> # ip link show em1
> 2: em1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state
> DOWN mode DEFAULT addrgenmode none group default qlen 1000
>     link/ether aa:bb:cc:dd:ee:ff brd ff:ff:ff:ff:ff:ff

Hi Thomas,

the upstream feature has been backported and 'ip -d link show' now works as expected. That is slightly different than what your bug report original said in that it is not done by default for 'ip link show'. If you still want this detail changed, please try to persuade upstream to accept such a change first.

Cheers,

Pavel

(In reply to Pavel Šimerda (pavlix) from comment #12)
> (In reply to Thomas Haller from comment #0)
> > # ip link show em1
> > 2: em1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state
> > DOWN mode DEFAULT addrgenmode none group default qlen 1000
> >     link/ether aa:bb:cc:dd:ee:ff brd ff:ff:ff:ff:ff:ff
> 
> Hi Thomas,
> 
> the upstream feature has been backported and 'ip -d link show' now works as
> expected. That is slightly different than what your bug report original said
> in that it is not done by default for 'ip link show'. If you still want this
> detail changed, please try to persuade upstream to accept such a change
> first.

no, that is ok.

It was only important to have a common system tool (iproute2) to be able to see the addrgenmode in some way. Requiring "-d" is fine.

Thank you.

Hi,

the new build removed mention about addrgenmode from ip-link man page.

# rpm -q iproute
iproute-3.10.0-21.el7.x86_64

# man ip-link | col -b | grep 'addrgenmode'
               addrgenmode { eui64 | none }  }
       addrgenmode eui64 or addrgenmode none

# rpm -q iproute
iproute-3.10.0-26.el7.x86_64

# man ip-link | col -b | grep 'addrgenmode'

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2015-2117.html