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Without a DNS server #4

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Expand Up @@ -38,6 +38,8 @@ First, we need a subdomain that we can use to receive incoming DNS requests. In
log4jdnsreq 3600 IN NS log4jchecker.northwave.nl.
```

[Note that installing a server is not stricly necessary, see "Without a DNS server".]

We now set up a BIND DNS server on a Debian system using `apt install bind9` and add the following to the `/etc/bind/named.conf.options` file:

```
Expand All @@ -59,6 +61,16 @@ logging {
```
Don't forget to restart BIND using `systemctl restart bind9`. Check if the logging works by performing a DNS query for `xyz.log4jdnsreq.northwave.nl`. One or more queries should show up in `/var/log/named/query.log`.

### Without a DNS server

You can also do without a DNS server. Just run `tcpdump` on the machine where the domain name is delegated. An example on the machine of IP address `2001:db8::beef`:

```
tcpdump -n dst host 2001:db8::beef and dst port 53
```

`tcpdump` will display the DNS requests received.

## Running the script

Install any Python dependencies using `pip install -r requirements.txt`. Edit the script to change the following line to the DNS zone you configured:
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