{FYI] eth0:avahi and constant eth0 network negotiating

[GreyGeek]

Sometime within the last week or so I began noticing a slowing down in the bootup, the login and in my network connection speed. Today I decided to see what the problem was. I opened ksystemlog and noticed the following:
[size=4pt]

06/14/11 03:29:56 pm  sonyvgnfw140e  avahi-autoipd(eth0)[2638]  Found user 'avahi-autoipd' (UID 104) and group 'avahi-autoipd' (GID 110).
06/14/11 03:29:56 pm  sonyvgnfw140e  avahi-autoipd(eth0)[2638]  Successfully called chroot().
06/14/11 03:29:56 pm  sonyvgnfw140e  avahi-autoipd(eth0)[2638]  Successfully dropped root privileges.
06/14/11 03:29:56 pm  sonyvgnfw140e  avahi-autoipd(eth0)[2638]  Starting with address 169.254.4.197
06/14/11 03:29:57 pm  sonyvgnfw140e  init  bootchart post-stop process (2598) terminated with status 1
06/14/11 03:30:01 pm  sonyvgnfw140e  avahi-autoipd(eth0)[2638]  Callout BIND, address 169.254.4.197 on interface eth0
06/14/11 03:30:01 pm  sonyvgnfw140e  avahi-daemon[1038] Joining mDNS multicast group on interface eth0.IPv4 with address 169.254.4.197.
06/14/11 03:30:01 pm  sonyvgnfw140e  avahi-daemon[1038] New relevant interface eth0.IPv4 for mDNS.
06/14/11 03:30:01 pm  sonyvgnfw140e  avahi-daemon[1038] Registering new address record for 169.254.4.197 on eth0.IPv4.
06/14/11 03:30:05 pm  sonyvgnfw140e  avahi-autoipd(eth0)[2638]  Successfully claimed IP address 169.254.4.197
06/14/11 03:30:05 pm  sonyvgnfw140e  init  ssh main process (2389) terminated with status 255
06/14/11 03:30:05 pm  sonyvgnfw140e  ntpd[2432] ntpd exiting on signal 15
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpdate[2708]  adjust time server 91.189.94.4 offset -0.382612 sec
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2761] ntpd 4.2.4p8@1.1612-o Tue Apr 19 07:08:18 UTC 2011 (1)
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] precision = 1.000 usec
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] ntp_io: estimated max descriptors: 1024, initial socket boundary: 16
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] Listening on interface #0 wildcard, 0.0.0.0#123 Disabled
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] Listening on interface #1 wildcard, ::#123 Disabled
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] Listening on interface #2 lo, 127.0.0.1#123 Enabled
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] Listening on interface #3 eth0:avahi, 169.254.4.197#123 Enabled
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] Listening on interface #4 wlan0, 192.168.1.100#123 Enabled
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] Listening on interface #5 wlan0, fe80::216:eaff:fe4d:58aa#123 Enabled
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] Listening on interface #6 lo, ::1#123 Enabled
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] kernel time sync status 2040
06/14/11 03:30:06 pm  sonyvgnfw140e  ntpd[2762] frequency initialized -5.426 PPM from /var/lib/ntp/ntp.drift
06/14/11 03:33:15 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 6
06/14/11 03:33:21 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 11
06/14/11 03:33:32 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 18
06/14/11 03:33:50 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 18
06/14/11 03:34:08 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
06/14/11 03:34:16 pm  sonyvgnfw140e  dhclient  No DHCPOFFERS received.
06/14/11 03:34:16 pm  sonyvgnfw140e  dhclient  No working leases in persistent database - sleeping.
06/14/11 03:34:27 pm  sonyvgnfw140e  ntpd[2762] synchronized to 91.189.94.4, stratum 2
06/14/11 03:34:27 pm  sonyvgnfw140e  ntpd[2762] time reset -0.252012 s
06/14/11 03:34:27 pm  sonyvgnfw140e  ntpd[2762] kernel time sync status change 2001
06/14/11 03:35:01 pm  sonyvgnfw140e  CRON[3364] (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
06/14/11 03:38:09 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 4
06/14/11 03:38:13 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 6
06/14/11 03:38:19 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 16
06/14/11 03:38:35 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 15
06/14/11 03:38:50 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
06/14/11 03:38:58 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 10
06/14/11 03:39:08 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 2
06/14/11 03:39:10 pm  sonyvgnfw140e  dhclient  No DHCPOFFERS received.
06/14/11 03:39:10 pm  sonyvgnfw140e  dhclient  No working leases in persistent database - sleeping.
06/14/11 03:41:47 pm  sonyvgnfw140e  ntpd[2762] synchronized to 91.189.94.4, stratum 2
06/14/11 03:42:13 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3
06/14/11 03:42:16 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3
06/14/11 03:42:19 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
06/14/11 03:42:27 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 11
06/14/11 03:42:38 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 12
06/14/11 03:42:50 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7
06/14/11 03:42:57 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 14
06/14/11 03:43:11 pm  sonyvgnfw140e  dhclient  DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3
06/14/11 03:43:14 pm  sonyvgnfw140e  dhclient  No DHCPOFFERS received.
06/14/11 03:43:14 pm  sonyvgnfw140e  dhclient  No working leases in persistent database - sleeping.
06/14/11 03:45:01 pm  sonyvgnfw140e  CRON[4295] (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
....
over, and over, and over, and over...

As you can see, eth0, to which I have nothing connected, was constantly poling dhcp for a proffer, which the wireless router had to process, slowing my internet connection down.

I also noticed something else when I did "ifconfig" in a Konsole:

eth0:avahi

bound to an IP address of 169.254.4.197. This turned out to be related to automatically finding dns services, local services, devices, fs, etc..., but I had never noticed this before in my network listings.

At first I tried disabling the avahi-daemon by editing the "/etc/default/avahi-daemon" file:

# 1 = Try to detect unicast dns servers that serve .local and disable avahi in
# that case, 0 = Don't try to detect .local unicast dns servers, can cause
# troubles on misconfigured networks
AVAHI_DAEMON_DETECT_LOCAL=1

and changing AVAHI_DAEMON_DETECT_LOCAL to 0. Upon rebooting that didn't work. So, I did:

sudo update-rc.d -f avahi-daemon remove

and rebooted, but that didn't work either.

Lastly, I changed the eth0 stanza in the /etc/network/interface file from

auto eth0
iface eth0 inet dhcp

to

allow-hotplug eth0
iface eth0 inet dhcp

and left AVAHI_DAEMON_DETECT_LOCAL = 0.

I immediately noticed that rebooting was much quicker, and so was the network login. My system log is MUCH quiter, with "debian-sa1" laying down a line every five minutes or so.