Network Interface eth or wlan but want both

[Defiant1]

So I decided to look into Arch ARM for my PI. I installed it and worked at getting the wireless up and running. Success, so far.

I am connecting my wlan to the same network as my eth and they both are getting an IP, if I unplug the eth the wlan will communicate out and if I disable wlan the eth still communicates. All seems to be going good.

The issue is noticed when I try to ping or try to ssh the wlan from another computer, it won't connect; however, if I disconnect the eth, I can communicate to the wlan. I looked all over and could not find an answer. It acts like the description of the failover configuration, but that is not setup.

So why can I only communicate to wlan, if eth is down? What am I missing?

Here is what I have done so far after the install to get the wlan up...
$this->bbcode_second_pass_code('', '
pacman -S netcrl
cp /etc/netctl/example/wireless-wpa /etc/netctl/
chmod 640 /etc/netctl/wireless-wpa
systemctl enable netctl-auto@wlan0
netctl start wireless-wpa
')

My wireless-wpa profile
$this->bbcode_second_pass_code('', 'Description='A simple WPA encrypted wireless connection'
Interface=wlan0
Connection=wireless

Security=wpa
IP=dhcp
IP6=no
ESSID='ssid''
# Prepend hexadecimal keys with \"
# If your key starts with ", write it as '""<key>"'
# See also: the section on special quoting rules in netctl.profile(5)
Key='password'
# Uncomment this if your ssid is hidden
#Hidden=yes
# Set a priority for automatic profile selection
#Priority=10
')

[TheSaint]

Have you check this ?$this->bbcode_second_pass_code('', '$ ip route
# netctl status wireless-wpa
').

[graysky]

I don't use netctl. Systemd can do it once you configure and enable wpa_aupplicant to work with wlan0. Just make these units and enable systemd-networkd and systemd-resolved.
$this->bbcode_second_pass_code('', '
% cat 10-wireless.network
[Match]
Name=wlan0

[Network]
DHCP=ipv4

[DHCP]
RouteMetric=10
')

$this->bbcode_second_pass_code('', '
% cat 20-wired.network
[Match]
Name=eth0

[Network]
DHCP=ipv4

[DHCP]
RouteMetric=20
')
Because this system runs kodi and needs nfs:
$this->bbcode_second_pass_code('', '
% cat /etc/systemd/system/systemd-networkd-wait-online.service.d/override.conf
[Service]
ExecStart=
ExecStart=/usr/lib/systemd/systemd-networkd-wait-online --ignore eth0
')

$this->bbcode_second_pass_code('', '
% cat /etc/systemd/system/kodi.service.d/override.conf
[Unit]
After=remote-fs.target network-online.target
Wants=network-online.target
')

[Defiant1]

$this->bbcode_second_pass_quote('TheSaint', 'H')ave you check this ?$this->bbcode_second_pass_code('', '$ ip route
# netctl status wireless-wpa
').

[TheSaint]

I saw two default route assignment. That might be incorrect.
What happen if you put down the wlan0 ? Will you have a route for both directions ?

[Defiant1]

This is now what I have

ifconfig wlan0 down
ifconfig
$this->bbcode_second_pass_code('', 'eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.67 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::ba27:ebff:fe42:b008 prefixlen 64 scopeid 0x20<link>
ether b8:27:eb:42:b0:08 txqueuelen 1000 (Ethernet)
RX packets 350 bytes 25464 (24.8 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 146 bytes 25527 (24.9 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0')

ip route
$this->bbcode_second_pass_code('', 'default via 192.168.1.1 dev eth0 proto dhcp src 192.168.1.67 metric 1024
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.67
192.168.1.1 dev eth0 proto dhcp scope link src 192.168.1.67 metric 1024')


netctl status wireless-wpa
$this->bbcode_second_pass_code('', '* netctl@wireless\x2dwpa.service - Networking for netctl profile wireless-wpa
Loaded: loaded (/usr/lib/systemd/system/netctl@.service; static; vendor preset: disabled)
Active: active (exited) since Sat 2018-09-08 17:06:30 UTC; 2h 19min ago
Docs: man:netctl.profile(5)
Process: 324 ExecStart=/usr/lib/netctl/network start wireless-wpa (code=exited, status=0/SUCCESS)
Main PID: 324 (code=exited, status=0/SUCCESS)
Status: "online"
Tasks: 2 (limit: 2212)
CGroup: /system.slice/system-netctl.slice/netctl@wireless\x2dwpa.service
|-343 wpa_supplicant -q -B -P /run/wpa_supplicant-wlan0.pid -i wlan0 -D nl80211,wext -c/run/netctl/wpa_supplicant-wlan0.conf
`-446 dhcpcd -4 -q -t 30 -L wlan0

Sep 08 17:06:35 alarmpi dhcpcd[394]: wlan0: adding route to 192.168.1.0/24
Sep 08 17:06:35 alarmpi dhcpcd[394]: wlan0: adding default route via 192.168.1.1
Sep 08 17:06:52 alarmpi dhcpcd[394]: forked to background, child pid 446
Sep 08 17:06:52 alarmpi network[324]: Started network profile 'wireless-wpa'
Sep 08 17:19:58 alarmpi dhcpcd[446]: wlan0: hardware address 00:00:00:00:00:00 claims 192.168.1.73
Sep 08 18:13:23 alarmpi dhcpcd[446]: wlan0: hardware address 00:00:00:00:00:00 claims 192.168.1.73
Sep 08 19:13:23 alarmpi dhcpcd[446]: wlan0: hardware address 00:00:00:00:00:00 claims 192.168.1.73
Sep 08 19:25:26 alarmpi dhcpcd[446]: wlan0: carrier lost
Sep 08 19:25:26 alarmpi dhcpcd[446]: wlan0: deleting route to 192.168.1.0/24
Sep 08 19:25:26 alarmpi dhcpcd[446]: wlan0: deleting default route via 192.168.1.1')

[Defiant1]

@graysky
$this->bbcode_second_pass_quote('', 'I') don't use netctl. Systemd can do it once you configure and enable wpa_aupplicant

[Defiant1]

FOUND the issue. The wlan interface needs to be set to a promiscuous mode. Now it will accept data from both interfaces. Now I just need to find, how to do this automatically.

[TheSaint]

Wouldn't it be bonding ?
Anyway I read about a package that will detect when the ethernet is plugged in. At that point it may trigger to start your script.