Linux System Log avahi-daemon[3733]: Invalid query packet

A large number of avahi-daemon[3733 were found when checking the log files of Linux]: Invalid query packet error (different number of servers corresponds)

3 07:00:01 hostname auditd[3143]: Audit Daemon Rotating log files

3 08:02:39 hostname avahi-daemon[3733]: Invalid query packet.

3 08:03:19 hostname Last message repeated 7 times

3 08:29:24 hostname avahi-daemon[3733]: Invalid query packet.

3 08:32:34 hostname Last message repeated 9 times

3 08:35:19 hostname Last message repeated 9 times

3 08:44:45 hostname Last message repeated 9 times

3 08:45:50 hostname Last message repeated 9 times

3 08:47:05 hostname Last message repeated

3 08:48:06 hostname Last message repeated

3 09:18:35 hostname avahi-daemon[3733]: Invalid query packet.

3 09:49:22 hostname Last message repeated 8 times

3 10:04:32 hostname Last message repeated times

3 11:52:49 hostname Last message repeated 8 times

3 11:55:38 hostname Last message repeated 8 times

3 13:13:15 hostname Last message repeated 8 times

3 13:18:26 hostname Last message repeated 8 times

3 13:50:10 hostname Last message repeated 7 times

3 13:58:21 hostname Last message repeated

3 14:29:48 hostname Last message repeated

3 14:35:45 hostname Last message repeated 8 times

3 14:36:49 hostname Last message repeated

3 14:48:23 hostname Last message repeated 9 times

3 16:02:28 hostname Last message repeated 6 times

3 16:03:30 hostname Last message repeated times

3 16:06:30 hostname Last message repeated

3 16:20:00 hostname Last message repeated 8 times

Avahi-daemon is a service daemon that runs on the client computer on a Linux operating system to find a network-based zeroconf service. The service can implement DNS service discovery and DNS multicast specifications for the ZEROCONF network. The user program receives notifications of discovery of network services and resources through the Linux D-bus information delivery. The daemon works with the cached user program's responses to help reduce network traffic resulting from replies.

Online search for some data shows that this is a bug (see Resources), I checked all the Rhel 5.7 versions of the Linux server on hand, almost all of the above error message. Online users suggest: Unless you have a compatible device or use the ZEROCONF protocol services, it should be closed.

[[email protected] log] # service Avahi-daemon status

Avahi Daemon is running

[[email protected] log] # service Avahi-daemon Stop

Shutting down Avahi daemon: [OK]

[[email protected] log] # chkconfig--list |grep Avahi-daemon

Avahi-daemon 0:off 1:off 2:off 3:on 4:on 5:on 6:off

[[email protected] log] # chkconfig Avahi-daemon off

[[email protected] log] # chkconfig--list |grep Avahi-daemon

Avahi-daemon 0:off 1:off 2:off 3:off 4:off 5:off 6:off

Also, it is recommended to turn off this service in the Rhel5-guide-i731.pdf documentation: if possible, disable the Avahi service as much as possible. This can reduce network attacks. As shown below:

3.7.1 Disable Avahi Server if Possible

Because The Avahi daemon Service keeps an open network port, it's subject to network attacks. Disabling it is

Particularly important to reduce the system's vulnerability to such attacks.

3.7.1.1 Disable Avahi Server Software

Issue the command:

# chkconfig Avahi-daemon off

3.7.1.2 Remove Avahi Server iptables Firewall Exception

Edit the Files/etc/sysconfig/iptables and/etc/sysconfig/ip6tables (if IPV6 is with use). In each file, locate and delete the line:

-A rh-firewall-1-input-p UDP--dport 5353-d 224.0.0.251-j ACCEPT

By default, the inbound connections to Avahi ' s port is allowed. If The Avahi server is not a being used, this exception

Should is removed from the firewall configuration. See sections 2.5.5 For more information about the Iptables firewall.

Resources:

http://blog.csdn.net/zhaojian1988/article/details/9214673

https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/500365

Http://www.question-defense.com/2010/09/15/centos-linux-avahi-error-avahi-daemon2699-invalid-query-packet

Linux System Log avahi-daemon[3733]: Invalid query packet