exitHow to fix/setup direct ethernet connection between 2 computers?
https://askubuntu.com/questions/1557392/exithow-to-fix-setup-direct-ethernet-connection-between-2-computers
Previous setup:
- raspberry A (dev a) is directly connected with an ethernet cable to jetson nano (dev B)
- dev B shall be replaced by dev C
the devices have static IPs:
- A: 192.168.0.3/24
- B: 192.168.0.1/24
- C: 192.168.0.4/24
Ping from A to B and from B to A works.
After replacing B with C and reboot, B can not ping A.
If I connect B with C, then I can ping C.
There is no router, switch etc. involved.
How can I debug this?

Appended:
raspberry 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: enxb827eb56b1a2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether b8:27:eb:56:b1:a2 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.3/24 brd 192.168.0.255 scope global dynamic enxb827eb56b1a2
valid_lft 43170sec preferred_lft 43170sec
inet6 fe80::3ee9:fe7a:f1c0:ef15/64 scope link
valid_lft forever preferred_lft forever
3: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
x
raspberry ip route list:
default via 192.168.0.6 dev enxb827eb56b1a2 proto static metric 100
16x.2xx.0.0/16 dev enxb827eb56b1a2 scope link metric 1000
192.168.0.0/24 dev enxb827eb56b1a2 proto kernel scope link src 192.168.0.3 metric 100
new jetson 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: can0: <NOARP,ECHO> mtu 16 qdisc noop state DOWN group default qlen 10
link/can
3: wlP1p1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
x
4: l4tbr0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 3e:c7:e7:79:f3:87 brd ff:ff:ff:ff:ff:ff
5: usb0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast master l4tbr0 state DOWN group default qlen 1000
link/ether 3e:40:2e:db:c6:45 brd ff:ff:ff:ff:ff:ff
6: usb1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast master l4tbr0 state DOWN group default qlen 1000
link/ether 3e:40:2e:db:c6:47 brd ff:ff:ff:ff:ff:ff
7: enP8p1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 3c:6d:66:b3:b8:d2 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.4/24 brd 192.168.0.255 scope global noprefixroute enP8p1s0
valid_lft forever preferred_lft forever
8: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
x
new jetson ip route list:
default via 131.x dev wlP1p1s0 proto dhcp metric 600
131.x/27 dev wlP1p1s0 proto kernel scope link src 131.246.87.175 metric 600
16x/16 dev wlP1p1s0 scope link metric 1000
17x/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
192.168.0.0/24 dev enP8p1s0 proto kernel scope link src 192.168.0.4 metric 100
old jetson 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: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 96:3e:1b:b6:c6:ad brd ff:ff:ff:ff:ff:ff
3: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 48:b0:2d:2f:70:c7 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.6/24 brd 192.168.0.255 scope host eth0
valid_lft forever preferred_lft forever
inet6 fe80::4ab0:2dff:fe2f:70c7/64 scope link
valid_lft forever preferred_lft forever
4: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1348 qdisc mq state UP group default qlen 1000
x
5: l4tbr0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 5e:0a:e7:39:91:ed brd ff:ff:ff:ff:ff:ff
6: rndis0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast master l4tbr0 state DOWN group default qlen 1000
link/ether 5e:0a:e7:39:91:ed brd ff:ff:ff:ff:ff:ff
7: usb0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast master l4tbr0 state DOWN group default qlen 1000
link/ether 5e:0a:e7:39:91:ef brd ff:ff:ff:ff:ff:ff
old jetson ip route list:
default via 10.x dev wlan0 proto dhcp metric 600
10.x dev wlan0 proto kernel scope link src 10.x metric 600
169x/16 dev eth0 scope link metric 1000
192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.6