Please add an optional parameter to bind the servers binaries (hbbs/hbbr) to only one network interface / one IP adress

[MatrixUser]

Hi everybody,

I am running the arm_v7 version of the rustdesk-server on a Fritz!Box 7690.

This device uses the same physical interface for the lan with to different names and IP adresses.

lan Link encap:Ethernet HWaddr 60:B5:8D:FB:0C:0B
inet addr:192.168.1.254 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::62b5:8dff:fefb:c0b/64 Scope:Link
inet6 addr: fd85:c829:cd63:0:62b5:8dff:fefb:c0b/64 Scope:Global
inet6 addr: 2001:9e8:1a9:8a00:62b5:8dff:fefb:c0b/64 Scope:Global
UP BROADCAST RUNNING ALLMULTI MULTICAST MTU:1500 Metric:1
RX packets:101927 errors:0 dropped:0 overruns:0 frame:0
TX packets:201585 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9603336 (9.1 MiB) TX bytes:50893203 (48.5 MiB)

lan:0 Link encap:Ethernet HWaddr 60:B5:8D:FB:0C:0B
inet addr:169.254.1.1 Bcast:169.254.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING ALLMULTI MULTICAST MTU:1500 Metric:1

The IP address for the interface "lan" is user configurable and in my case it is 192.168.1.254, while the second interface named "lan:0" has the fixed (APIPA) IP adress 169.254.1.1. The APIPA address is provided just in the case that the user has forgotten the IP of the Fritz!Box. To enable client connections from the internet I forwarded the used ports (tcp 21115-21117 and udp 21116) to the IP 192.168.1.254 and everything works fine.

Now here is my problem: Normally it should be possible to forward the ports to the (emergency) IP address 169.254.1.1 instead of the (normal) IP address 192.168.1.254, since this is the same physical interface. As long as the client which should connect to the server is in my own LAN and uses the address 169.254.1.1 as ID/Relayserver everything works. But when forwarding to 169.254.1.1 the server cannot be reached from the internet. Nevertheless a port scanner shows that the necessary ports are open.

My educated guess is that my problem is somehow similar to the problem described in this bug report:
#447
For troubleshooting it would be helpful to have an optional parameter which forces the server components to bind only to one interface and one IP address, e.g.

hbbs -k _ [ IP=x.x.x.x]
hbbr -k _ [ IP=x.x.x.x]
rustdesk-utils doctor rustdesk-server [IP=x.x.x.x]

If the optional parameter is given, the programs should only bind to the interface with the given IP address. If the optional parameter is omitted, the programs are bound to all interfaces, which is the current behavior.

C.U. MatrixUser