How to set up a bridge interface, add eth0 to it, and have internet connection

I am trying to set up br0 with eth0 and veth1 on a headless server where I am logged in via ssh. I am doing this as a preparation to run a systemd service in a special namespace. This namespace will have the peer of the virtual divice as it's endpoint: veth2. This should make it possible to set up static routes for just this process. In my case it will then route packages through a vpn while all the other traffic goes to the standard gateway. To figure out how this works I wrote a small script that executes the following so fast that the ssh connection to the server does not break. I can then traceroute the veth2 successfully. The server has just one eth device and no wifi which is why I have to do it this way. My problem is that after executing the script the server does not have internet access any more. I am probably missing a lot here. Can anyone help? My script: pi@testpi:~ $ cat add_bridge_and_veth1.sh brctl addbr br0; ip addr del 192.168.100.222/24 dev eth0; ip addr add 192.168.100.222/24 dev br0; brctl addif br0 eth0; ip link set dev br0 up; ip link add name veth1 type veth peer name veth2; brctl addif br0 veth1; brctl show; ip netns add nsben1; ip link set veth2 netns nsben1; ip netns exec nsben1 ip addr add 192.168.55.101/24 dev veth2; ip netns exec nsben1 ip link set lo up; ip netns exec nsben1 ip link set veth2 up; No internet after this in the default namespace: pi@testpi:~ $ traceroute 8.8.8.8 traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets 1 192.168.100.222 (192.168.100.222) 3085.668 ms !H 3085.488 ms !H 3085.393 ms !H pi@testpi:~ $ ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. From 192.168.100.222 icmp_seq=1 Destination Host Unreachable EDIT: My default setup is very simple. eth0 gets a fixed IP in 192.168.100.0/24 from the router according to the MAC of the device: 192.168.100.222. pi@testpi:~ $ ip a 1: lo: 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: mtu 1500 qdisc pfifo_fast master br0 state UP group default qlen 1000 link/ether b8:27:eb:98:70:4b brd ff:ff:ff:ff:ff:ff inet 192.168.100.222/24 brd 192.168.100.255 scope global dynamic noprefixroute eth0 valid_lft 83282sec preferred_lft 72482sec inet6 fe80::247e:fd3c:36d7:68f5/64 scope link valid_lft forever preferred_lft forever 3: br0: mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether b8:27:eb:98:70:4b brd ff:ff:ff:ff:ff:ff inet 192.168.100.222/24 scope global br0 valid_lft forever preferred_lft forever inet6 fe80::ba27:ebff:fe98:704b/64 scope link valid_lft forever preferred_lft forever 5: veth1@if4: mtu 1500 qdisc noqueue master br0 state UP group default qlen 1000 link/ether e2:bc:58:01:67:92 brd ff:ff:ff:ff:ff:ff link-netns nsben1 inet 169.254.205.121/16 brd 169.254.255.255 scope global noprefixroute veth1 valid_lft forever preferred_lft forever inet6 fe80::db71:b4e9:c60f:5865/64 scope link valid_lft forever preferred_lft forever No network in nsben1, but this is not my main concern yet. I first want to have everything working in default namespace. root@testpi:~# ip netns exec nsben1 ping 8.8.8.8 connect: Network is unreachable Here the output for ip route in default and nsben1 namespaces. I think Network is unreachable from the nsben1 results from the internet beeing unreachable from default namespace. It does not necessarily mean that something is wrong with the nsben1, but even if that's not the main problem at the moment. root@testpi:~# ip route 192.168.55.0/24 dev veth2 proto kernel scope link src 192.168.55.101 root@testpi:~# ip route get 8.8.8.8 RTNETLINK answers: Network is unreachable root@testpi:~# ip netns exec nsben1 ip route 192.168.55.0/24 dev veth2 proto kernel scope link src 192.168.55.101 root@testpi:~# ip netns exec nsben1 ip route get 8.8.8.8 RTNETLINK answers: Network is unreachable For the sake of completeness ip a in nsben1: root@testpi:~# ip netns exec nsben1 ip a 1: lo: 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 4: veth2@if5: mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 92:31:7e:0f:89:9d brd ff:ff:ff:ff:ff:ff link-netnsid 0 inet 192.168.55.101/24 scope global veth2 valid_lft forever preferred_lft forever inet6 fe80::9031:7eff:fe0f:899d/64 scope link valid_lft forever preferred_lft forever ------ **I tried @berndbausch's approach** of just executing the first five commands brctl addbr br0; ip addr del 192.168.100.222/24 dev eth0; ip addr add 192.168.100.222/24 dev br0; brctl addif br0 eth0; ip link set dev br0 up; in a script. When I do this I get the following output, where br0 and eth0 still have the same IP, which probably is wrong: pi@testpi:~ $ sudo ./add_bridge.sh pi@testpi:~ $ ip route 192.168.100.0/24 dev br0 proto kernel scope link src 192.168.100.222 pi@testpi:~ $ ip a 1: lo: 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: mtu 1500 qdisc pfifo_fast master br0 state UP group default qlen 1000 link/ether b8:27:eb:98:70:4b brd ff:ff:ff:ff:ff:ff inet 192.168.100.222/24 brd 192.168.100.255 scope global dynamic noprefixroute eth0 valid_lft 86389sec preferred_lft 75589sec inet6 fe80::247e:fd3c:36d7:68f5/64 scope link valid_lft forever preferred_lft forever 3: br0: mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether b8:27:eb:98:70:4b brd ff:ff:ff:ff:ff:ff inet 192.168.100.222/24 scope global br0 valid_lft forever preferred_lft forever inet6 fe80::ba27:ebff:fe98:704b/64 scope link valid_lft forever preferred_lft forever I then tried to execute the script adding ip link set dev eth0 down; and up like this: ip link set dev eth0 down; brctl addif br0 eth0; ip link set dev eth up; I lose the connection via ssh which is understandable. Maybe it is normal that eth0 has the same IP as the br0 it is connected to. If not, why is the IP not removed despite me using ip addr del 192.168.100.222/24 dev eth0;