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Running CentOS 5.4

Why do I have route to 169.254.0.0 although it does not appear in Network > Ethernet Device > Route configuration dialog?

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     *               255.255.255.0   U     0      0        0 eth2
169.254.0.0     *               255.255.0.0     U     0      0        0 eth2
default         192.168.1.1     0.0.0.0         UG    0      0        0 eth2
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From this article on the Red Hat Knowledgebase:

How do I disable the zeroconf route so that the system will boot without the 169.254.0.0 / 255.255.0.0 route?

Symptom:

Every time the system boots, the zeroconf route (169.254.0.0) is enabled. You manually disable it by turning off the firewall and remove the route with 169.254.0.0 / 255.255.0.0 using the route command.

Example output of the route with the zeroconf route enables would like similar to the following:

# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.15.50.0      *               255.255.252.0   U     0      0        0 eth0
169.254.0.0     *               255.255.0.0     U     0      0        0 eth0

Solution:

To disable the zeroconf route during system boot, edit the /etc/sysconfig/network file and add the following NOZEROCONF value to the end of the file:

NETWORKING=YES
HOSTNAME=localhost.localdomain
NOZEROCONF=yes
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I like Marcel's answer but it doesn't really address the question. The question was 'Why do I have..', not 'How can I disable'. The OP may in fact not want to disable this route.

The 169.254.0.0/16 network is used for Automatic Private IP Addressing, or APIPA. If a DHCP client attempts to get an address, but fails to find a DHCP server after the timeout and retries period it will randomly assume an address from this network. This allows communication with hosts that have failed to obtain a DHCP address.

  • 2
    I think he knew that. He really wanted to know why the route appears although his DHCP (if he uses one) obviously worked because he has an IP address on that interface different from 169... Why do I have ? ... and as the answer says ... because you didn't disable it :) – user126330 Apr 15 '10 at 14:31
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    Marcel: Maybe, maybe not. Your answer was great, just wanted to make sure he understood why he would have a 169.254 entry to begin with. :) – Kyle Smith Apr 15 '10 at 16:20
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    and I appreciate it , thank you ... what is SF if not the perfect place to get the complete answer :) – user126330 Apr 15 '10 at 19:01
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    If he knew it he is not really smart enough to use a computer because he still asks WHY it is there. Or, if you do not assume the OP is a total idiot then assuming he knew it is not smart because he explicitly asks where it came from, not how to disable it. Does not get more explicit. – TomTom Jan 13 '14 at 7:42

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