OPNsense Forum

English Forums => General Discussion => Topic started by: clst on July 28, 2026, 07:33:59 PM

Title: Super strange Bridge issue with paket filtering and a Grandstream phone
Post by: clst on July 28, 2026, 07:33:59 PM
Bridge is on 4 ports and working generally fine.

I have set up filtering on the bridge instead of the ports as per the guide.

Now the issue is: The phone works fine, can be called, UDP and TCP packet travel along nicely. But every time I try to call an external number (other internal extensions work great): It looks like the packets for initiating the connection get silently dropped.

During troubleshooting I tried a Linux softphone on the same port and it works fine. Plugging the non-working phone into a switch connected to OPNSense also works fine. And now the weirdest part: as soon as I toggle System - Advanced - Disable Firewall to disable all packet filtering. The phone can make calls.
I checked the MTU and it's fine. I checked with and without the block port 0 rule. Devices from the Wifi on the OPNSense box also work (but sadly that phone has no Wifi).

I am totally baffled. I have all checkboxes enabled for logging in advanced. And there are zero dropped packets in the log. I have a rule to allow interface LAN (the bridge) to LAN anything right at the top:

pass log quick on bridge0 inet from {any} to {any} keep state label "f8e58ab2-ea70-4831-a28f-1392c52478d4" # LAN bridge ALLOW ALL
all rules in /tmp/rules.debug have log enabled. And there is nothing to see in the live view. Not even an rdr from a rogue NAT rule.
The log on the Asterisk box doesn't show anything out of the ordinary. The SIP messages to actually connect the call just never arrive.

Does anyone have a hint?

I tried doing a packet log from the phone, but the firmware crashed, lol.
Packet log on the OPNSense box?

OPNsense 26.1.11_6-amd64