IP address losing even when eth0 up

[Muthyam]

Hello Community,

I am using SPEAR-MX8, I am losing IP even when the eth0 link is up.

imx8qm-var-som-lcd login:
imx8qm-var-som-lcd login: root
Last login: Sun Sep 20 10:44:03 UTC 2020
root@imx8qm-var-som-lcd:~#
root@imx8qm-var-som-lcd:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether f8:dc:7a:b4:f0:56 brd ff:ff:ff:ff:ff:ff
inet6 fe80::6550:e95b:67d5:4d08/64 scope link noprefixroute
valid_lft forever preferred_lft forever
root@imx8qm-var-som-lcd:~# ifconfig eth0 10.0.0.10
root@imx8qm-var-som-lcd:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether f8:dc:7a:b4:f0:56 brd ff:ff:ff:ff:ff:ff
inet 10.0.0.10/8 brd 10.255.255.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::6550:e95b:67d5:4d08/64 scope link noprefixroute
valid_lft forever preferred_lft forever
root@imx8qm-var-som-lcd:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether f8:dc:7a:b4:f0:56 brd ff:ff:ff:ff:ff:ff
inet6 fe80::6550:e95b:67d5:4d08/64 scope link noprefixroute
valid_lft forever preferred_lft forever
root@imx8qm-var-som-lcd:~# dmesg | grep eth0
[ 2.163732] fec 5b040000.ethernet eth0: registered PHC device 0
[ 10.931511] fec 5b040000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[ 10.931553] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
root@imx8qm-var-som-lcd:~#

What is causing the issue.

Thank You,

Muthyam D.

[JosephAtNXP]

Hi,

Thank you for your interest in NXP Semiconductor products,

How is the network set? What cables are connected to what.

Try resetting the interface and then assign the IP.

$ ip link set eth0 down
$ ip link set eth0 up
$ ip addr add <address>

Regards

[Muthyam]

Hello,
We are using NetworkManager,
When assigning IP dynamically through a switch, no problem is occurring. But When trying assign static IP using "ifconfig eth0 10.0.0.10 up" the above mentioned problem occurred.

Same with your suggested commands also,

We have connected a four pin ethernet cable from laptop to SoM.

root@imx8qm-var-som:~#
root@imx8qm-var-som:~# ip link set eth0 down
root@imx8qm-var-som:~# ip link set eth0 up
root@imx8qm-var-som:~# ip addr add 10.0.0.10/24 dev eth0
root@imx8qm-var-som:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether f8:dc:7a:b4:f0:56 brd ff:ff:ff:ff:ff:ff
inet 10.0.0.10/24 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::fab9:5ef7:a8e:bb73/64 scope link noprefixroute
valid_lft forever preferred_lft forever
root@imx8qm-var-som:~# ping 10.0.0.5
PING 10.0.0.5 (10.0.0.5) 56(84) bytes of data.
64 bytes from 10.0.0.5: icmp_seq=1 ttl=64 time=3.88 ms
.....
64 bytes from 10.0.0.5: icmp_seq=29 ttl=64 time=2.02 ms
ping: sendmsg: Network is unreachable
ping: sendmsg: Network is unreachable
^C
--- 10.0.0.5 ping statistics ---
43 packets transmitted, 29 received, 32.5581% packet loss, time 42356ms
rtt min/avg/max/mdev = 1.705/2.023/3.881/0.362 ms
root@imx8qm-var-som:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether f8:dc:7a:b4:f0:56 brd ff:ff:ff:ff:ff:ff
inet6 fe80::fab9:5ef7:a8e:bb73/64 scope link noprefixroute
valid_lft forever preferred_lft forever
root@imx8qm-var-som:~# dmesg | grep eth0
[ 2.206788] fec 5b040000.ethernet eth0: registered PHC device 0
[ 10.546412] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 10.548625] fec 5b040000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[ 49.682668] fec 5b040000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[ 49.682721] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
root@imx8qm-var-som:~#

Thank You,

Muthyam D.

[JosephAtNXP]

Hi,

Do you router assign a 10.0.0 subnet address when an IP is dynamically given?

Have you tried to statically assign an IP within the subnet? It could be that there is no route for a 10.0.0 host.

Regards,