Internet only after dhclient, how to get ip after download?

Question

linux

All with the upcoming!
I apologize in advance for the noob question.
There is a PC (Debian), it worked like a home ball, one bad person tried to set up Internet distribution on it. His actions are not known. What happened. The network is not expanded and eth0 does not see the network, there is no Internet, it does not receive ip. After dhclient eth0 - everything becomes normal, but after reboot everything is the same. I can't figure out what settings are missing.
uname-a

Linux HomeMedia 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u2 (2016-10-19) x86_64 GNU/Linux

cat /proc/version

Linux version 3.16.0-4-amd64 ([email protected]) (gcc version 4.8.4 (Debian 4.8.4-1) ) #1 SMP Debian 3.16.36-1+deb8u2 (2016-10-19)

cat /etc/network/interfaces

# This file describes the network interfaces available on your system
and how to activate them. For more information, see interfaces(5).
source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
allow-hotplug eth0
iface eth0 inet dhcp

lspci

00:00.0 Host bridge: Intel Corporation Broadwell-U Host Bridge -OPI (rev 09)
00:02.0 VGA compatible controller: Intel Corporation Broadwell-U Integrated Graphics (rev 09)
00:03.0 Audio device: Intel Corporation Broadwell-U Audio Controller (rev 09)
00:14.0 USB controller: Intel Corporation Wildcat Point-LP USB xHCI Controller (rev 03)
00:16.0 Communication controller: Intel Corporation Wildcat Point-LP MEI Controller #1 (rev 03)
00:1c.0 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #1 (rev e3)
00:1c.2 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #3 (rev e3)
00:1c.3 PCI bridge: Intel Corporation Wildcat Point-LP PCI Express Root Port #4 (rev e3)
00:1d.0 USB controller: Intel Corporation Wildcat Point-LP USB EHCI Controller (rev 03)
00:1f.0 ISA bridge: Intel Corporation Wildcat Point-LP LPC Controller (rev 03)
00:1f.2 SATA controller: Intel Corporation Wildcat Point-LP SATA Controller [AHCI Mode] (rev 03)
00:1f.3 SMBus: Intel Corporation Wildcat Point-LP SMBus Controller (rev 03)
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0c)
03:00.0 Network controller: Qualcomm Atheros Device 0042 (rev 30)

ifconfig -a

eth0      Link encap:Ethernet  HWaddr 98:ee:cb:29:b5:38  
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:40 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3160 (3.0 KiB)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:27 errors:0 dropped:0 overruns:0 frame:0
          TX packets:27 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:2652 (2.5 KiB)  TX bytes:2652 (2.5 KiB)

ping vk.com
unknown host vk.com
192.168.1.20 is a home PC (Ubuntu) ping 192.168.1.20
connect: Network is unreachable
when pinging 192.168.1.1 (router) the result does not change
route -n

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface

dmesg | grep eth

[    0.686970] r8169 0000:02:00.0 eth0: RTL8168g/8111g at 0xffffc90000660000, 98:ee:cb:29:b5:38, XID 0c000800 IRQ 62
[    0.686974] r8169 0000:02:00.0 eth0: jumbo features [frames: 9200 bytes, tx checksumming: ko]
[   11.612448] r8169 0000:02:00.0 eth0: link down
[   11.612479] r8169 0000:02:00.0 eth0: link down
[   11.612498] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[   13.494074] r8169 0000:02:00.0 eth0: link up
[   13.494083] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready

picture after dhclient eth0
route -n

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 eth0
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0

ifconfig

eth0      Link encap:Ethernet  HWaddr 98:ee:cb:29:b5:38  
          inet addr:192.168.1.10  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:60 errors:0 dropped:0 overruns:0 frame:0
          TX packets:43 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:4799 (4.6 KiB)  TX bytes:6032 (5.8 KiB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:32 errors:0 dropped:0 overruns:0 frame:0
          TX packets:32 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:3132 (3.0 KiB)  TX bytes:3132 (3.0 KiB)

dmesg | grep eth

[    0.686970] r8169 0000:02:00.0 eth0: RTL8168g/8111g at 0xffffc90000660000, 98:ee:cb:29:b5:38, XID 0c000800 IRQ 62
[    0.686974] r8169 0000:02:00.0 eth0: jumbo features [frames: 9200 bytes, tx checksumming: ko]
[   11.612448] r8169 0000:02:00.0 eth0: link down
[   11.612479] r8169 0000:02:00.0 eth0: link down
[   11.612498] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[   13.494074] r8169 0000:02:00.0 eth0: link up
[   13.494083] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready

I would like to return everything as it was, otherwise it is not convenient to enter dhclient every time after a reboot.
Thank you in advance!

Answer 1

I solved the issue by deleting and creating with rights 0777 /etc/network/interfaces

Answer 2

Is the second line in interfaces commented out or was it copied here with a transfer?
Remove allow-hotplug eth0