This is a really weird problem that no one seems to be able to cast light on.
Let me start with what I am hoping to achieve,
I want a PI 4 or 5 (testing on 4B currently) to act as a wifi hotspot, with a bridge to the Ethernet port. DHCP etc to be handled by the main router on the LAN.
Hardware/OS is as followsThe machine has a static IP address of 192.168.0.101, with a default route of 192.168.0.254, which is a Draytek router which handles DHCP for transient clients.
Apart from the bridge, software is mostly default, although I am running tvheadend and a TV hat.
To achieve the bridge I used Network Manager (nm-cli) to set up the Ethernet, Wifi and Bridge interfaces as follows
The relevant configuration files are in /etc/Network-ManagerTheir contents are as follows:
sudo cat br0.nmconnectionAnd the Ethernet interface:
sudo cat Ethernet.nmconnectionAnd finally the wifi interface...
cat Garden.nmconnectionNow the first thing to say, is that this does work. I can log a wifi client in and see my LAN at reasonable wifi speeds, though the link only works in the same room at sane speeds. The Pi is running a web server and performance degrades when this is being accessed by the Ethernet interface.
The server itself can still see the internet all right through the ethernet interface.
But any attempt to connect to the Internet from a wifi attached client leads to around 90% packet loss.
DNS is not involved, I used pure IP addresses to ping.
As far as I can tell the CPU is not overstressed, nor are there any errors in the log file (thank you systemd...not!). There is plenty of free RAM.
Now I have been in IP networking a LONG time. so I don't think I have made a trivial mistake. And I wouldn't be asking here if I wasn't completely stumped.
I have included all the relevant files so that anyone with a spare Pi 4 or 5 can set up a test to duplicate mine.
Thanking any helpers in advance.
Let me start with what I am hoping to achieve,
I want a PI 4 or 5 (testing on 4B currently) to act as a wifi hotspot, with a bridge to the Ethernet port. DHCP etc to be handled by the main router on the LAN.
Hardware/OS is as follows
Code:
$ hostnamectl Static hostname: Coriolanus Pretty hostname: |Coriolanus Icon name: computer Machine ID: 40d7cbf8a8124ae7b2201252c3fa8bbb Boot ID: 7ca6fdc4c4d3475899c7716663d19729Operating System: Debian GNU/Linux 12 (bookworm) Kernel: Linux 6.12.47+rpt-rpi-v8 Architecture: arm64Apart from the bridge, software is mostly default, although I am running tvheadend and a TV hat.
To achieve the bridge I used Network Manager (nm-cli) to set up the Ethernet, Wifi and Bridge interfaces as follows
Code:
$ ip link1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:002: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master nm-bridge state UP mode DEFAULT group default qlen 1000 link/ether d8:3a:dd:85:22:b1 brd ff:ff:ff:ff:ff:ff3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master nm-bridge state UP mode DORMANT group default qlen 1000 link/ether d8:3a:dd:85:22:b2 brd ff:ff:ff:ff:ff:ff4: nm-bridge: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether d8:3a:dd:85:22:b1 brd ff:ff:ff:ff:ff:ffCode:
/etc/NetworkManager/system-connections$ ls -ltotal 12-rw------- 1 root root 313 Jan 16 15:10 br0.nmconnection-rw------- 1 root root 220 Jan 16 15:38 Ethernet.nmconnection-rw------- 1 root root 314 Jan 16 15:38 Garden.nmconnectionsudo cat br0.nmconnection
Code:
[connection]id=br0uuid=db3fc586-63b4-43f6-9cf3-efd207086553type=bridgeinterface-name=nm-bridgetimestamp=1768487381[ethernet]mtu=1500[bridge]forward-delay=0stp=false[ipv4]address1=192.168.0.101/24,192.168.0.254dns=192.168.0.101;method=manual[ipv6]addr-gen-mode=defaultmethod=disabled[proxy]sudo cat Ethernet.nmconnection
Code:
[connection]id=Ethernetuuid=4a8b7eb6-678a-47e2-b5b2-416cc800438ftype=ethernetinterface-name=eth0master=db3fc586-63b4-43f6-9cf3-efd207086553slave-type=bridgetimestamp=1768487382[ethernet]mtu=1500[bridge-port]cat Garden.nmconnection
Code:
[connection]id=Gardenuuid=f977bba8-bda3-404b-89c3-57c959c8b1fdtype=wifiinterface-name=wlan0master=db3fc586-63b4-43f6-9cf3-efd207086553slave-type=bridgetimestamp=1768576422[wifi]band=bgchannel=9mode=apmtu=1500powersave=2ssid=Garden[wifi-security]key-mgmt=wpa-pskpsk=dead.ratz[bridge-port]The server itself can still see the internet all right through the ethernet interface.
But any attempt to connect to the Internet from a wifi attached client leads to around 90% packet loss.
DNS is not involved, I used pure IP addresses to ping.
As far as I can tell the CPU is not overstressed, nor are there any errors in the log file (thank you systemd...not!). There is plenty of free RAM.
Now I have been in IP networking a LONG time. so I don't think I have made a trivial mistake. And I wouldn't be asking here if I wasn't completely stumped.
I have included all the relevant files so that anyone with a spare Pi 4 or 5 can set up a test to duplicate mine.
Thanking any helpers in advance.
Statistics: Posted by Leo Smith — Tue Jan 27, 2026 2:37 pm — Replies 0 — Views 16