RHEL 6 NOZEROCONF

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Is NOZEROCONF still an option in RHEL 6 /etc/sysconfig/network file?

I did see the variable listed under the RHEL 6 deployment guide for /etc/sysconfig/network

Thank you for your time.

Responses

Hi,

yes, it is still valid option.

//Zdenek

For your reference, all possible configuration parameters are documented in sysconfig.txt shipped with the initscripts package:

# locate sysconfig.txt
/usr/share/doc/initscripts-9.03.49/sysconfig.txt

# rpm -qf $(locate sysconfig.txt)
initscripts-9.03.49-1.el6.x86_64

# egrep -A2 ZEROCONF $(locate sysconfig.txt)
  NOZEROCONF=
    Set this to not set a route for dynamic link-local addresses.

--
    NOZEROCONF=
      Set this to not set a route for dynamic link-local addresses
      over this device.

Thanks all....I didnt see an accepeted value in that file....Should it be like RHEL 5 true/false or yes/no?

In this https://access.redhat.com/solutions/8627 they use yes/no,,,

//Zdenek

I have never liked NOZEROCONF as an option mainly because it can lead to a double negative, eg.

NOZEROCONF=no

But more importantly, it doesn't appear to behave how you would expect, see this:
http://www.linuxstories.eu/2011/02/zero-configuration-network-zeroconf.html

The value for the "NOZEROCONF" parameter can actually be set to any value, the initscripts only check to determine whether the parameter has zero length. So setting "NOZEROCONF=no" will have the same effect as setting it to "yes". You will need to comment or remove the variable to reactive ZEROCONF.

Not sure if this is still the case, will need to test again.

You're correct, ifup-eth and ifup-ib only check if the string is non-zero:

# Add Zeroconf route.
if [ -z "${NOZEROCONF}" -a "${ISALIAS}" = "no" -a "${REALDEVICE}" != "lo" ]; then
    ip route add 169.254.0.0/16 dev ${REALDEVICE} metric $((1000 + $(cat /sys/class/net/${REALDEVICE}/ifindex))) scope link
fi

I have just searched the Deployment Guide and cannot find 'NOZEROCONF' documented there. I think the best is to file a bug against 'initscripts' to get the 'sysconfig.txt' improved to explain this.

One could also update https://access.redhat.com/solutions/8627.

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