1

I am trying to set a static ip address. The static ip is outside of my home dhcp range. But even after reboot, I can connect to the old dhcp ip address. Why does this happen? Take a look at the ip during login and in the ouput of ifconfig:

login as: pi
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Last login: Tue Jan 5 20:54:59 2016 from flucky-pc.lan

pi@druckerpi:~ $ ifconfig

eth0 Link encap:Ethernet Hardware Adresse b8:27:eb:7b:45:2b
 inet Adresse:192.168.0.3 Bcast:192.168.0.255 Maske:255.255.255.0
 inet6-Adresse: fe80::ba27:ebff:fe7b:452b/64 Gültigkeitsbereich:Verbindung
 UP BROADCAST RUNNING MULTICAST MTU:1500 Metrik:1
 RX packets:11358 errors:0 dropped:0 overruns:0 frame:0
 TX packets:1300 errors:0 dropped:0 overruns:0 carrier:0
 Kollisionen:0 Sendewarteschlangenlänge:1000
 RX bytes:631413 (616.6 KiB) TX bytes:133922 (130.7 KiB)
lo Link encap:Lokale Schleife
 inet Adresse:127.0.0.1 Maske:255.0.0.0
 inet6-Adresse: ::1/128 Gültigkeitsbereich:Maschine
 UP LOOPBACK RUNNING MTU:65536 Metrik:1
 RX packets:41 errors:0 dropped:0 overruns:0 frame:0
 TX packets:41 errors:0 dropped:0 overruns:0 carrier:0
 Kollisionen:0 Sendewarteschlangenlänge:0
 RX bytes:5671 (5.5 KiB) TX bytes:5671 (5.5 KiB)

pi@druckerpi:~ $ cat /etc/network/interfaces

# interfaces(5) file used by ifup(8) and ifdown(8)
# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 192.168.0.3
netmask 255.255.255.0
gateway 192.168.0.1
dns-nameservers 192.168.0.1
#allow-hotplug wlan0
#iface wlan0 inet manual
# wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
#allow-hotplug wlan1
#iface wlan1 inet manual
# wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
pi@druckerpi:~ $

Is there something I am missing? I DONT want to be able to connect to 192.168.0.205 and instead use the static ip 192.168.0.3 (as set in /etc/network/interfaces)

Milliways
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asked Jan 5, 2016 at 22:45
2
  • I assume you are running Raspbian? What version are you running? Did you see this line For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf' in the /etc/network/interfaces file you included above? The method of configuring networking has changed. This forum thread raspberrypi.org/forums/viewtopic.php?f=63&t=110606has all the good/bad details. Note the title seems off topic, but the details of the new method of setting a static IP using /etc/dhcpcd.conf file are there. Commented Jan 5, 2016 at 22:52
  • 1
    Check whether there is some setting in your home router (e.g. dhcp with "fixed" ip address) if you find the Pi (or its former IP listed there) - try to delete it. Commented Jan 5, 2016 at 22:52

2 Answers 2

1

I assume that by now, your host computer ARP cache table no longer remember the 192.168.0.205 IP Address.

arp -in eth0

Will show you the association between IP and MAC addresses. Unless someone else reuse the same IP with a new MAC, the ARP protocol will keep it alive for some time. You can also clear that table, O/S dependent, with commands like:
Windows:

arp -d * 

Linux:

ip -s -s neigh flush all
answered Jan 5, 2016 at 23:10
1
  • My raspberry is still running (over a year now) and today I was able to connect via ssh to the old (wrong) ip from my question from another laptop. Over a year in arp cache? Commented Feb 14, 2017 at 19:09
2

The method of setting a static IP has changed (this has rasied some questions and ire from the community, but it is what it is). Evidence of this can be seen in the comments of the /etc/network/interfaces file you included above, namely these two lines:

Please note that this file is written to be used with dhcpcd

For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf

To set up a static IP using the new dhcpd system edit your /etc/wpa_supplicant/wpa_supplicant.conf file so that it only contains the SSID and psk:

network={
 ssid="xxxxx"
 psk="xxxxxx"
}

and the static IP details are in the /etc/dhcpcd.conf file:

# Static IP configuration
interface eth0
static ip_address=192.168.0.3/24
static routers=192.168.0.1
static domain_name_servers=8.8.8.8 8.8.4.4

You will also have to edit your /etc/network/interfaces file so that the eth0 entry looks like this:

auto eth0
allow-hotplug eth0
iface eth0 inet manual

More info can be found in this forum thread. Despite the title of the thread it does include the details of the new setup as well as some of the anger this change has caused.

answered Jan 5, 2016 at 23:06
6
  • Hi is connecting to 192.168.0.205 however, ifconfig shows 192.168.0.3 (in German adresse) Commented Jan 5, 2016 at 23:14
  • @Fcm One of the problems the switch in network config has made is double IP address assignment the forum thread is actually titled /etc/network/interfaces changed,weird 2 LAN IPs instead of 1 Commented Jan 5, 2016 at 23:17
  • 1
    For a less passionate and easier to follow answer see raspberrypi.stackexchange.com/a/37921/8697 (I agree the actions of certain Foundation developers making fundamental changes without updating the documentation is irresponsible.) Commented Jan 5, 2016 at 23:18
  • @Milliwaysmy personal favorite is that to set a static Ip you use a file called dhcpd, and set the mode as manual not the most intuitive naming scheme Commented Jan 5, 2016 at 23:20
  • @SteveRobillard I could not agree more! Of course my personal favourite (hobby horse) is to NOT use static, and let the computer do the work. Commented Jan 5, 2016 at 23:50

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