# Troubleshooting

### Unknown bpf_trace_printk

```
invalid argument: unknown func bpf_trace_printk
```

Solution:

Compile dae with CFLAG `-D__REMOVE_BPF_PRINTK`. See [build-by-yourself](build-by-yourself.md).

### Binding to WAN but no network

**1. Troubleshoot local DNS service**

If you use `systemd-resolved`, `dnsmasq` or other local DNS service in `/etc/resolv.conf`, do not use their DNS service.

Methods to disable their DNS service:

1. Method 1: by modifying their configurations.
2. Method 2: by modifying the content of `/etc/resolv.conf` to `nameserver 223.5.5.5` or other DNS.

Alternatively, if you really want to use them, refer to [external-dns](external-dns.md).

**2. Troubleshoot firewall**

If you bind to wan, make sure firewall is stopped or `12345` is allowed by firewall. Don't worry about the security of this port because this port has its own firewall rule.

Usual firewalls on Linux:

```
ufw
firewalld
```

**3. Troubleshoot PPPoE**

dae does not support PPPoE yet. We are working on it. However, binding to LAN for other machines should work fine.

### Binding to LAN but bad DNS in other machines

To verify:

```
curl -i 1.1.1.1
curl -i google.com
```

If the first line has a response and the second line doesn't, check whether port `53` is occupied by others on dae's machine.

```
netstat -ulpen|grep 53
# or
# lsof -i:53 -n
```

If does, stop the service process or change its listening port from 53 to others.

### Common troubleshooting