Duplicated GenericIPAddressField validation errors with ModelSerializer and protocol

[HansAarneLiblik]

Hi!

I'm using GenericIPAddressField with explicit protocol as IPv4 (Also reproduces with IPv6) and ModelSerializer. If the input is not an valid IpAddress, DRF generates duplicate(ish) errors.

Repro

from django.db import models
from rest_framework.serializers import ModelSerializer


class A(models.Model):
    address = models.GenericIPAddressField(protocol="IPv4")  # Also reproduces with `IPv6`

    class Meta:
        app_label = "main"

class ASerializer(ModelSerializer[A]):
    class Meta:
        model = A
        fields = "__all__"


ser = ASerializer(data={'address': 'not an ip address'})
ser.is_valid(raise_exception=True)

Result

rest_framework.exceptions.ValidationError: {'address': [
    ErrorDetail(string='Enter a valid IPv4 address.', code='invalid'), 
    ErrorDetail(string='Enter a valid IPv4 or IPv6 address.', code='invalid')
]}

The second error message is incorrect

Thanks!

• Raised initially as discussion - Can't, it gets deleted automatically - https://groups.google.com/g/django-rest-framework/c/eNNq1UYeww4
• This is not a feature request suitable for implementation outside this project. Please elaborate what it is:
  • other type of bug fix
• I have reduced the issue to the simplest possible case.

[Daksh2000]

Hi @HansAarneLiblik , Can I take this issue ?

[HansAarneLiblik]

Sure, I don't mind!

[Daksh2000]

Hi @HansAarneLiblik ,
I have raised a PR , #9647
Please share your views on it.

[NikeGunn]

Issue Analysis and Suggestion: Duplicate Validation Errors on GenericIPAddressField

Summary

When using GenericIPAddressField(protocol="IPv4") in a Django model along with a DRF ModelSerializer, submitting an invalid IP address triggers two error messages:

• Enter a valid IPv4 address.
• Enter a valid IPv4 or IPv6 address.

The second message is incorrect, since the model explicitly restricts the protocol to IPv4 only.

---

Why this happens

Internally, DRF generates its own set of validators on top of Django’s GenericIPAddressField. It appears that DRF incorrectly adds a general-purpose IPv4/IPv6 validation even when the model is explicitly restricted to a single protocol (like IPv4 or IPv6).

---

Suggestion for the Author

The serializer field generated for GenericIPAddressField should properly respect the protocol restriction from the model. DRF should only apply validators that match the defined protocol.
Specifically:

• If protocol="IPv4", only IPv4 validation errors should occur.
• If protocol="IPv6", only IPv6 validation errors should occur.
• The generic "IPv4 or IPv6" validation should not be applied when the model field is restricted.

---

Temporary Workaround

You can manually override the serializer field to avoid the issue:

from rest_framework import serializers

class ASerializer(serializers.ModelSerializer):
    address = serializers.IPAddressField(protocol="IPv4")  # Explicitly set the correct protocol

    class Meta:
        model = A
        fields = "__all__"