SOAP messages being sent from op-node to EL

[emlautarom1]

At Nethermind we're running op-node together with the Nethermind client, and from time to time both OP and Base nodes send SOAP messages for an unrelated protocol: TR-069

An example of messages that we might receive is the following:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<soap_env:Envelope
xmlns:soap_env="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:soap_enc="http://schemas.xmlsoap.org/soap/encoding/"
xmlns:cwmp="urn:dslforum-org:cwmp-1-2">
<soap_env:Body>
<cwmp:Inform>
<DeviceId>
<Manufacturer>DISCOVERYSERVICE</Manufacturer>
<OUI>DISCOVERYSERVICE</OUI>
<ProductClass>DISCOVERYSERVICE</ProductClass>
<SerialNumber>SdvKJzhzwN</SerialNumber>
</DeviceId>
<Event soap_enc:arrayType="cwmp:EventStruct[1]">
<EventStruct>
<EventCode>M ScheduleInform</EventCode>
<CommandKey />
</EventStruct>
</Event>
</cwmp:Inform>
</soap_env:Body>
</soap_env:Envelope>

It's not clear to us why we're getting these kind of messages but they cause issues since we're expecting all request to be JSON objects, thus failing during deserialization.

The original issue and more details are available in NethermindEth/nethermind#8015 (comment)