I used to have a Netgear Nighthawk router where my raspberry pi 3 was able to connect to WiFi, ethernet, SSH, everything I needed.
Using the same Pi but now plugged into a TP-Link Archer A9 router, I can not get any connection at all with an ethernet cord. The router interface at (192.168.0.1) does not show a wired connection coming from the Pi either. The router LED glows as if the Pi's ethernet cord is connected. If I connect the Pi to the router through WiFi, I am able to then see the Pi on the TP-Link router's interface (192.168.0.1). If I use the IP address in this interface to SSH, it works! However, it still doesn't have internet access.
For example, when the pi is connected to the router through WiFi, I am able to SSH into the pi and execute the following.
pi@raspberrypi:~ $ sudo ping google.com
PING google.com (172.217.4.78) 56(84) bytes of data.
From 192.168.1.5 (192.168.1.5) icmp_seq=1 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=2 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=3 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=4 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=5 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=6 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=7 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=8 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=9 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=10 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=11 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=12 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=13 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=14 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=15 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=16 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=17 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=18 Destination Host Unreachable
From 192.168.1.5 (192.168.1.5) icmp_seq=19 Destination Host Unreachable
^C
--- google.com ping statistics ---
21 packets transmitted, 0 received, +19 errors, 100% packet loss, time 928ms
pipe 4
pi@raspberrypi:~ $
Edit: Suggested to run the following commands.
pi@raspberrypi:~ $ ip a && ip r
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 pfifo_fast state UP group default qlen 1000
link/ether b8:27:eb:c0:4c:d6 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.5/24 brd 192.168.1.255 scope global noprefixroute eth0
valid_lft forever preferred_lft forever
inet6 fe80::9caa:4457:4097:e21a/64 scope link
valid_lft forever preferred_lft forever
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether b8:27:eb:95:19:83 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.247/24 brd 192.168.0.255 scope global noprefixroute wlan0
valid_lft forever preferred_lft forever
inet6 fe80::2305:6f6d:a1c4:9e73/64 scope link
valid_lft forever preferred_lft forever
default via 192.168.1.1 dev eth0 src 192.168.1.5 metric 202
default via 192.168.0.1 dev wlan0 proto dhcp src 192.168.0.247 metric 303
192.168.0.0/24 dev wlan0 proto dhcp scope link src 192.168.0.247 metric 303
192.168.1.0/24 dev eth0 proto dhcp scope link src 192.168.1.5 metric 202
pi@raspberrypi:~ $ ethtool eth0
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Link partner advertised pause frame use: Symmetric Receive-only
Link partner advertised auto-negotiation: Yes
Link partner advertised FEC modes: Not reported
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
Cannot get wake-on-lan settings: Operation not permitted
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes
pi@raspberrypi:~ $
ip a && ip r
and alsoethtool eth0
– Milliways Dec 11 '20 at 05:17ip a && ip r
shows you are connected to 2 different networks. We can only guess why. See How to set up networking/WiFi – Milliways Dec 13 '20 at 04:55