IPwatchD - IP conflict detection tool for Linux

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1. Is this project abandoned/dead?

IPwatchD project is neither abandoned nor dead. It is just in the stable phase where there are no new releases until there are no new bugs found.

2. IPwatchD does not work! It did not detect my IP conflict!

In order to detect IP conflict the machine running IPwatchD has to receive ARP broadcasts generated by the conflicting host. Some machines generate ARP broadcasts during the change of IP address others don't. In such cases you have to wait until some other host on your network initiates communication with the conflicting IP address. Conflicting machine will most likely use ARP broadcasts during the initiation of new communication with the other host and this will give IPwatchD a chance to detect IP conflict. You can find out more about this topic in my whitepaper "Detection of IP conflict in Linux".

3. Can IPwatchD running on my server detect all IP conflicts in my LAN?

IPwatchD is designed to monitor and protect only the system it is running on. If you want to monitor a whole network you should rather use arpwatch.

4. I have installed IPwatchD but it did not resolve the conflict.

IPwatchD does not resolve the IP conflicts it just informs the user that IP conflict exists. Please note that IP conflict is a serious network misconfiguration and it should be resolved by changing IP address of one of the conflicting hosts.

5. I have read an article describing how to use IPwatchD to automatically win the race for IP address. What do you think about it?

Exactly the same "aggressive behavior" as described in that article can be achieved without send_arp just by using active protection mode with defend_interval set to 0. However I strongly discourage you from this kind of setup. IP conflict is a serious network misconfiguration and it should be resolved by changing IP address of one of the conflicting hosts.

6. Does IPwatchD support IPv6?

IPwatchD currently supports only IPv4 mostly because I don't use IPv6 on my systems. While it should be possible to use IPv6 Neighbor Discovery Protocol (NDP) to perform Duplicate address detection (DAD) I will probably do nothing about it until I start using IPv6 on my own systems. Collaborators and/or sponsors are welcome meanwhile :)

7. Desktop notifications do not work! Log entry with IP conflict exists but I've seen no notification bubble.

Desktop notifications are displayed by the separate application IPwatchD-G-Notify that is executed by IPwatchD daemon whenever the IP conflict occurs. It is a completely optional extension for desktop users and it is not needed on server machines.

IPwatchD-G-Notify displays notifications via libnotify which unfortunately has no support for "system-wide messages" and because of that IPwatchD-G-Notify uses little workaround when it tries to write message to all busses available. That is the main reason why IPwatchD-G-Notify requires less restrictive setup of D-BUS where root is allowed to write messages to busses belonging to regular users and this kind of setup can be found only in Debian/Ubuntu based distributions.

On other distributions you can either monitor system logs for information about IP conflict recorded by IPwatchD daemon or you can switch to Debian/Ubuntu :)

8. I have installed IPwatchD on RHEL but when I want to start daemon I am getting error "/etc/init.d/ipwatchd: line 34: /lib/init/vars.sh: No such file or directory". What should I do?

Init script shipped with IPwatchD 1.2.1 is designed for Debian/Ubuntu based distributions. You should replace the file "/etc/init.d/ipwatchd" with this one on RedHat derivatives.


© 2007-2013 Jaroslav Imrich