<!-- The comments between these brackets won't show up in the submitted issue (as you can see in the Preview). -->


<!-- Please try to download latest, https://github.com/schollz/croc/releases/latest of croc before reporting a bug! -->

## Describe the bug
<-- A clear and concise description of what the bug is. -->
Attempting to send a file locally over the LAN from host A to host B fails on host B (receiver) with error.
Sending files from host A to B through the default relay succeeds.

## To Reproduce
Steps to reproduce the behavior:
<-- 1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error -->

1. Host A (sender): croc --local send
2. Host A generates code
3. Host B (receiver): croc --local
4. Host B generates error

## Expected behaviour
<-- A clear and concise description of what you expected to happen. -->
Host B (receiver) should download file.

## Version
<-- Check "croc -v" and report it -->
croc v9.6.15

## Additional context
<-- Add any other context about the problem here. -->
Both hosts are on the same LAN and subnet. Both hosts run the same version of croc. Both hosts run Debian 12.

Sender & Receiver:
Debian 12 & croc v9.6.15

**Send Local Debug** ([debug.log](https://github.com/schollz/croc/files/15211582/debug.log)):

```
user@sender:/mnt/02/ISOIMG$ croc --debug --local send debian-12.5.0-amd64-netinst.iso >> debug.log                                         
Sending 'debian-12.5.0-amd64-netinst.iso' (629.0 MB)                                                                                                     
Code is: 4542-phantom-nickel-herbert                                                                                                                     
On the other computer run                                                                                                                                
                                                                                                                                                         
croc 4542-phantom-nickel-herbert
```

**Receive Local Debug:**

```
user@receiver:~/Downloads$ croc --debug --local 
[debug] 19:24:08 cli.go:150: debug mode on
Enter receive code: 4542-phantom-nickel-herbert
[debug] 19:24:12 croc.go:185: options: {IsSender:false SharedSecret:4542-phantom-nickel-herbert Debug:true RelayAddress:5.78.91.237:9009 RelayAddress6:[2a01:4ff:1f0:c10b::1]:9009 RelayPorts:[] RelayPassword:pass123 Stdout:false NoPrompt:false NoMultiplexing:false DisableLocal:false OnlyLocal:true IgnoreStdin:false Ask:false SendingText:false NoCompress:false IP: Overwrite:false Curve:p256 HashAlgorithm: ThrottleUpload: ZipFolder:false TestFlag:false GitIgnore:false}
connecting...[debug]    19:24:12 croc.go:785: attempt to discover peers
[debug] 19:24:12 croc.go:850: discoveries: []
[debug] 19:24:12 croc.go:851: establishing connection
[debug] 19:24:12 croc.go:879: could not connect to : found no addresses to connect
2024/05/04 19:24:12 could not connect to : found no addresses to connect
user@receiver:~/Downloads$ 
```

Send/Receive --local fails, firewall issue?
This is a GitHub Issue
repo:croc
owner:schollz
Title : Send/Receive --local fails, firewall issue?
Issue date:

--- start body ---
<!-- The comments between these brackets won't show up in the submitted issue (as you can see in the Preview). -->


<!-- Please try to download latest, https://github.com/schollz/croc/releases/latest of croc before reporting a bug! -->

## Describe the bug
<-- A clear and concise description of what the bug is. -->
Attempting to send a file locally over the LAN from host A to host B fails on host B (receiver) with error.
Sending files from host A to B through the default relay succeeds.

## To Reproduce
Steps to reproduce the behavior:
<-- 1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error -->

1. Host A (sender): croc --local send
2. Host A generates code
3. Host B (receiver): croc --local
4. Host B generates error

## Expected behaviour
<-- A clear and concise description of what you expected to happen. -->
Host B (receiver) should download file.

## Version
<-- Check "croc -v" and report it -->
croc v9.6.15

## Additional context
<-- Add any other context about the problem here. -->
Both hosts are on the same LAN and subnet. Both hosts run the same version of croc. Both hosts run Debian 12.

Sender & Receiver:
Debian 12 & croc v9.6.15

**Send Local Debug** ([debug.log](https://github.com/schollz/croc/files/15211582/debug.log)):

```
user@sender:/mnt/02/ISOIMG$ croc --debug --local send debian-12.5.0-amd64-netinst.iso >> debug.log                                         
Sending 'debian-12.5.0-amd64-netinst.iso' (629.0 MB)                                                                                                     
Code is: 4542-phantom-nickel-herbert                                                                                                                     
On the other computer run                                                                                                                                
                                                                                                                                                         
croc 4542-phantom-nickel-herbert
```

**Receive Local Debug:**

```
user@receiver:~/Downloads$ croc --debug --local 
[debug] 19:24:08 cli.go:150: debug mode on
Enter receive code: 4542-phantom-nickel-herbert
[debug] 19:24:12 croc.go:185: options: {IsSender:false SharedSecret:4542-phantom-nickel-herbert Debug:true RelayAddress:5.78.91.237:9009 RelayAddress6:[2a01:4ff:1f0:c10b::1]:9009 RelayPorts:[] RelayPassword:pass123 Stdout:false NoPrompt:false NoMultiplexing:false DisableLocal:false OnlyLocal:true IgnoreStdin:false Ask:false SendingText:false NoCompress:false IP: Overwrite:false Curve:p256 HashAlgorithm: ThrottleUpload: ZipFolder:false TestFlag:false GitIgnore:false}
connecting...[debug]    19:24:12 croc.go:785: attempt to discover peers
[debug] 19:24:12 croc.go:850: discoveries: []
[debug] 19:24:12 croc.go:851: establishing connection
[debug] 19:24:12 croc.go:879: could not connect to : found no addresses to connect
2024/05/04 19:24:12 could not connect to : found no addresses to connect
user@receiver:~/Downloads$ 
```

--- end body ---

The issue described does not indicate a security vulnerability but rather a connectivity problem when using the local file transfer feature of the croc application. The error seems to stem from the inability of the receiver to discover peers on the local network, which could be due to firewall settings or network configuration issues. This is a functionality-related bug rather than a security concern.