First of all I read a lot of thread about problems with connections but all referred to a Wi-Fi LAN adapter. My problem is on the eth0 LAN port.

I have a Raspberry Pi 2 Model B with the latest stable Raspbian installed. I use it as a DHCP server so I configured a static IP. The problem is: after a reboot, the LAN port seems disabled. No ping, ssh or VNC work. But if I connect via real VNC over the cloud I can access the RPi and immediately after connected eth0 starts and i can ping or access ssh.

It seems the LAN port wakes up after an external input.

But after some minutes after disconnect from VNC again the LAN port goes to sleep.

This is my /etc/network/interfaces:

iface eth0 inet static
        mtu 1500

And this is my /etc/dhcpcd.conf:

interface eth0
static ip_address=
static routers=
static domain_name_servers=
static domain_search=

I tried with

  • auto eth0
  • inet manual (instead static)
  • using a script executed on boot with sudo ifup eth0

but nothing worked...

On boot, the LAN port is not responding to pings.

  • 1
    I don't know anything about your network but this looks like an issue with arp reply. Connecting from the cloud (what ever this is) your pc get an arp reply from the pi 2 so the pc knows its mac address and stores it the arp cache. Without refresh the entry will be deleted after 300 sec by default. If you connect through your local network where arp reply does not work connection will work for max. 300 sec (without refresh from cloud connection). Mabye ... Is there any firewall?
    – Ingo
    Apr 21, 2018 at 11:09
  • 1
    You don't identify what OS exactly but do you think your problem might have something to do with ignoring the warning # Please note that this file is written to be used with dhcpcd # For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf' Unless you specify what you did no one can tell. Also your dhcpcd settings are wrong.
    – Milliways
    Apr 21, 2018 at 11:13
  • @Ingo: no firewall Apr 21, 2018 at 14:41
  • @Milliways: I followed tuts like this [raspberrypi.stackexchange.com/questions/37920/… where I can use both interfaces or dhcpcd.conf but still same problem. Connection goes up and down without reason. Apr 21, 2018 at 14:43
  • Could it be problem with power supply? I'm using a phone charger with 5.0V and 550mA. Apr 21, 2018 at 14:45

1 Answer 1


Solved the problem. My RPi was setted up correctly. The real problem was on LAN. There was another linux router with some network services still active that make conflicts with RPi. I supposed i stopped all network services on that machine but i was wrong. Without that machine on LAN, RPi working perfectly. Thanks to all for help.

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