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Lucas Aimaretto
Asked: 2019-09-03 09:36:20 +0800 CST

Cannot obtain DHCP address ubuntu 16.04 - ethernet card

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I've searched the web already about this issue. It seems many are facing it, but unfortunately none of those solutions seemed to have worked with me.

My latest is this one, where I've reinstalled the NIC driver.

I've also tried adding my card to the file /etc/network/interfaces so as to avoid NetworkManager using it, but the result is the same: endless DHCP Discover messages and no OFFER in response.

Sep  2 14:25:21 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 12 (xid=0xc5f73c43)
Sep  2 14:25:22 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 19 (xid=0xa5e64914)
Sep  2 14:25:33 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 12 (xid=0xc5f73c43)
Sep  2 14:25:41 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 11 (xid=0xa5e64914)
Sep  2 14:25:45 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 21 (xid=0xc5f73c43)
Sep  2 14:25:52 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 20 (xid=0xa5e64914)
Sep  2 14:26:06 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 17 (xid=0xc5f73c43)
Sep  2 14:26:12 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 9 (xid=0xa5e64914)
Sep  2 14:26:21 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 14 (xid=0xa5e64914)
Sep  2 14:26:23 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 16 (xid=0xc5f73c43)
Sep  2 14:26:35 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 16 (xid=0xa5e64914)
Sep  2 14:26:39 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 10 (xid=0xc5f73c43)
Sep  2 14:26:49 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 12 (xid=0xc5f73c43)
Sep  2 14:26:51 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 8 (xid=0xa5e64914)
Sep  2 14:26:59 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 12 (xid=0xa5e64914)
Sep  2 14:27:01 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 7 (xid=0xc5f73c43)
Sep  2 14:27:08 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 9 (xid=0xc5f73c43)
Sep  2 14:27:11 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 15 (xid=0xa5e64914)
Sep  2 14:27:17 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 14 (xid=0xc5f73c43)
Sep  2 14:27:26 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 19 (xid=0xa5e64914)
Sep  2 14:27:31 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 7 (xid=0xc5f73c43)
Sep  2 14:27:38 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 8 (xid=0xc5f73c43)
Sep  2 14:27:45 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 21 (xid=0xa5e64914)
Sep  2 14:27:46 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 9 (xid=0xc5f73c43)
Sep  2 14:27:55 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 7 (xid=0xc5f73c43)
Sep  2 14:28:02 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 12 (xid=0xc5f73c43)
Sep  2 14:28:06 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 18 (xid=0xa5e64914)
Sep  2 14:28:14 lucas-HP-240-G6-Notebook-PC dhclient[4514]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 17 (xid=0xc5f73c43)
Sep  2 14:28:24 lucas-HP-240-G6-Notebook-PC dhclient[4045]: DHCPDISCOVER on eno1 to 255.255.255.255 port 67 interval 20 (xid=0xa5e64914)

I've tried a different PC on my switch port, and it is getting and IPv4 address, so not the switch nor the DCHP Server are faulty.

Also, my wifi card gets connected to the AP.

This is my system:

lucas@lucas-HP-240-G6-Notebook-PC:~$ uname -a
Linux lucas-HP-240-G6-Notebook-PC 4.4.0-161-generic #189-Ubuntu SMP Tue Aug 27 08:10:16 UTC 2019 x86_64 x86_64 x86_64 GNU/Li

lucas@lucas-HP-240-G6-Notebook-PC:~$ lshw -c network
WARNING: you should run this program as super-user.
  *-network               
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: eno1
       version: 15
       serial: f4:30:b9:9e:5f:73
       size: 100Mbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8168 driverversion=8.046.00-NAPI duplex=full latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s
       resources: irq:126 ioport:4000(size=256) memory:b1104000-b1104fff memory:b1100000-b1103fff
  *-network
       description: Wireless interface
       product: Realtek Semiconductor Co., Ltd.
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlo1
       version: 00
       serial: 40:9f:38:22:15:ef
       width: 64 bits
       clock: 33MHz
       capabilities: bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=rtl8723de ip=10.10.39.74 latency=0 multicast=yes wireless=IEEE 802.11bgn
       resources: irq:131 ioport:3000(size=256) memory:b1000000-b100ffff
  *-network DISABLED
       description: Ethernet interface
       physical id: 1
       logical name: virbr0-nic
       serial: 52:54:00:da:ff:85
       size: 10Mbit/s
       capabilities: ethernet physical
       configuration: autonegotiation=off broadcast=yes driver=tun driverversion=1.6 duplex=full link=no multicast=yes port=twisted pair speed=10Mbit/s
WARNING: output may be incomplete or inaccurate, you should run this program as super-user.


lucas@lucas-HP-240-G6-Notebook-PC:~$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether f4:30:b9:9e:5f:73 brd ff:ff:ff:ff:ff:ff
    inet 169.254.8.56/16 brd 169.254.255.255 scope link eno1:avahi
       valid_lft forever preferred_lft forever
    inet6 fe80::8ae2:b747:3347:da25/64 scope link 
       valid_lft forever preferred_lft forever
3: wlo1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 40:9f:38:22:15:ef brd ff:ff:ff:ff:ff:ff
    inet 10.10.39.74/22 brd 10.10.39.255 scope global dynamic wlo1
       valid_lft 13766sec preferred_lft 13766sec
    inet6 fe80::cfdf:3c42:b81f:1af6/64 scope link 
       valid_lft forever preferred_lft forever
4: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
5: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether 52:54:00:da:ff:85 brd ff:ff:ff:ff:ff:ff

This is the content of /etc/network/interfaces...

lucas@lucas-HP-240-G6-Notebook-PC:~$ cat /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto eno1
iface eno1 inet dhcp

any hint?

thanks!

networking network-manager dhcp ethernet 16.04

0 Answers