Hi TC friends,
I use one TC 10.0 bootable USB thumb drive on many machines and all of them use eth0 for networking. Every now and then, I get a machine that will not connect to the Internet (it does connect using Windows). Per ifconfig, as far as I can tell, eth0 is discovered and present. I am hoping with your help I could learn how to troubleshoot this area Linux networking.
Below are some outputs from a PROBLEM system using various commands and with my comments I hope will give you enough details to suggest next steps. I have a simple router with typical 192.168.x.x addresses.
[~]{$?=0}Sun Sep 08 06:08:35 > dmesg | grep -i eth0
[ 1.939111] e1000e 0000:00:19.0 eth0: (PCI Express:2.5GT/s:Width x1) ec:f4:bb:39:95:xx
[ 1.939114] e1000e 0000:00:19.0 eth0: Intel(R) PRO/1000 Network Connection
[ 1.939173] e1000e 0000:00:19.0 eth0: MAC: 11, PHY: 12, PBA No: FFFFFF-0FF
[ 28.134290] e1000e: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
[~]{$?=0}Sun Sep 08 06:11:22 > lspci | grep -i eth
00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I217-LM (rev 04)
[~]{$?=0}Sun Sep 08 06:11:55 > ifconfig (notice no inet addr for eth0)
eth0 Link encap:Ethernet HWaddr EC:F4:BB:39:95:xx
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2 errors:0 dropped:0 overruns:0 frame:0
TX packets:29 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:514 (514.0 B) TX bytes:10034 (9.7 KiB)
Interrupt:20 Memory:f7d00000-f7d20000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:4 errors:0 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:200 (200.0 B) TX bytes:200 (200.0 B)
[~]{$?=0}Sun Sep 08 06:12:47 > netstat -r
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
127.0.0.1 * 255.255.255.255 UH 0 0 0 lo
[~]{$?=0}Sun Sep 08 06:13:52 > cat /etc/resolv.conf
[~]{$?=0}Sun Sep 08 06:16:20 >
[~]{$?=1}Sun Sep 08 06:17:00 > sudo udhcpc -i eth0
udhcpc: started, v1.29.3
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending discover etc etc would go forever I think....
^C
[~]{$?=130}Sun Sep 08 06:17:39 >
[/mnt/sdb1]{$?=0}Sun Sep 08 06:37:23 > curl wttr.in
curl: (6) Could not resolve host: wttr.in
I know from Windows ipconfig on this same system and network connection that these are the current IP details:
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) Ethernet Connection I217-LM
Physical Address. . . . . . . . . : EC-F4-BB-39-95-B5
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::e07c:d885:59ac:b2b4%12(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.12(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Sunday, September 08, 2019 6:54:37 AM
Lease Expires . . . . . . . . . . : Monday, September 09, 2019 6:54:36 AM
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DHCPv6 IAID . . . . . . . . . . . : 267187387
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-21-3B-8B-63-EC-F4-BB-39-95-B5
DNS Servers . . . . . . . . . . . : 192.168.1.1
NetBIOS over Tcpip. . . . . . . . : Enabled
now trying a few things on this problem system:
[/mnt/sdb1]{$?=0}Sun Sep 08 06:31:40 > sudo pkill udhcpc
[/mnt/sdb1]{$?=0}Sun Sep 08 06:32:11 > sudo ifconfig eth0 down
[/mnt/sdb1]{$?=0}Sun Sep 08 06:32:30 > sudo ifconfig eth0 hw ether EC:F4:BB:39:95:xx
[/mnt/sdb1]{$?=0}Sun Sep 08 06:32:49 > sudo ifconfig eth0 up
[/mnt/sdb1]{$?=0}Sun Sep 08 06:33:09 > sudo ifconfig eth0 192.168.1.12 netmask 255.255.255.0 broadcast 192.168.1.255 up
[/mnt/sdb1]{$?=0}Sun Sep 08 06:33:27 > sudo route add default gw 192.168.1.1
[/mnt/sdb1]{$?=0}Sun Sep 08 06:33:50 > sudo echo nameserver 192.168.1.1 >> /etc/resolv.conf
[/mnt/sdb1]{$?=0}Sun Sep 08 06:34:13 >
[/mnt/sdb1]{$?=0}Sun Sep 08 06:34:13 > ifconfig
eth0 Link encap:Ethernet HWaddr EC:F4:BB:39:95:xx
inet addr:192.168.1.12 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:7 errors:0 dropped:0 overruns:0 frame:0
TX packets:152 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1606 (1.5 KiB) TX bytes:52592 (51.3 KiB)
Interrupt:20 Memory:f7d00000-f7d20000
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:4 errors:0 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:200 (200.0 B) TX bytes:200 (200.0 B)
[/mnt/sdb1]{$?=130}Sun Sep 08 06:35:45 > sudo netstat -r
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
default 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
127.0.0.1 * 255.255.255.255 UH 0 0 0 lo
192.168.1.0 * 255.255.255.0 U 0 0 0 eth0
[/mnt/sdb1]{$?=0}Sun Sep 08 06:37:23 > curl wttr.in
curl: (6) Could not resolve host: wttr.in
No Internet.... sigh
Does anything jump out to you that I am missing? Or some suggestions for me to try next?
Below are some outputs from a GOOD system that does connect just fine, right away, first try. Same boot thumb drive.
[~]{$?=0}Sun Sep 08 06:42:38 > dmesg | grep -i eth0
[ 3.314002] e1000e 0000:00:19.0 eth0: (PCI Express:2.5GT/s:Width x1) 00:24:e8:97:28:xx
[ 3.314004] e1000e 0000:00:19.0 eth0: Intel(R) PRO/1000 Network Connection
[ 3.314033] e1000e 0000:00:19.0 eth0: MAC: 7, PHY: 8, PBA No: 1004FF-0FF
[ 40.754913] e1000e: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
[~]{$?=0}Sun Sep 08 06:43:35 > lspci | grep -i eth
00:19.0 Ethernet controller: Intel Corporation 82567LM Gigabit Network Connection (rev 03)
[~]{$?=0}Sun Sep 08 06:44:13 > ifconfig
eth0 Link encap:Ethernet HWaddr 00:24:E8:97:28:xx
inet addr:192.168.1.21 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3 errors:0 dropped:0 overruns:0 frame:0
TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:756 (756.0 B) TX bytes:692 (692.0 B)
Interrupt:22 Memory:f6fe0000-f7000000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:4 errors:0 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:200 (200.0 B) TX bytes:200 (200.0 B)
[~]{$?=0}Sun Sep 08 06:44:42 > netstat -r
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
default 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
127.0.0.1 * 255.255.255.255 UH 0 0 0 lo
192.168.1.0 * 255.255.255.0 U 0 0 0 eth0
[~]{$?=0}Sun Sep 08 06:45:11 > cat /etc/resolv.conf
nameserver 192.168.1.1
[~]{$?=0}Sun Sep 08 06:45:44 >
[~]{$?=0}Sun Sep 08 06:45:44 > sudo udhcpc -i eth0
udhcpc: started, v1.29.3
udhcpc: sending discover
udhcpc: sending select for 192.168.1.21
udhcpc: lease of 192.168.1.21 obtained, lease time 86400
deleting routers
route: SIOCDELRT: No such process
adding dns 192.168.1.1
[~]{$?=0}Sun Sep 08 06:46:26 > curl wttr.in
Weather report: Santa Cruz, United States
Thanks in advance and thanks to all who posted similar issues and troubleshooting suggestions and fixes to the forum. sorry if I just missed the obvious answer.
thank you
Billy
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