diff --git a/testing/btest/Files/mmdb/.gitignore b/testing/btest/Files/mmdb/.gitignore
new file mode 100644
index 0000000000..b4daca1937
--- /dev/null
+++ b/testing/btest/Files/mmdb/.gitignore
@@ -0,0 +1 @@
+testmmdb
diff --git a/testing/btest/Files/mmdb/GeoLite2-ASN.mmdb b/testing/btest/Files/mmdb/GeoLite2-ASN.mmdb
new file mode 100644
index 0000000000..65ade5917e
Binary files /dev/null and b/testing/btest/Files/mmdb/GeoLite2-ASN.mmdb differ
diff --git a/testing/btest/Files/mmdb/GeoLite2-City.mmdb b/testing/btest/Files/mmdb/GeoLite2-City.mmdb
new file mode 100644
index 0000000000..2f375e3bd6
Binary files /dev/null and b/testing/btest/Files/mmdb/GeoLite2-City.mmdb differ
diff --git a/testing/btest/Files/mmdb/README b/testing/btest/Files/mmdb/README
new file mode 100644
index 0000000000..269a36c045
--- /dev/null
+++ b/testing/btest/Files/mmdb/README
@@ -0,0 +1,13 @@
+These .mmdb databases were created with the mmdbwriter from MaxMind [1] for
+testing purposes. See the main.go file. They only contain information about
+LBL's network ranges:
+
+    128.3.0.0/16
+    131.243.0.0/16
+
+Rebuild with:
+
+    go build
+    ./testmmdb
+
+[1] https://github.com/maxmind/mmdbwriter
diff --git a/testing/btest/Files/mmdb/go.mod b/testing/btest/Files/mmdb/go.mod
new file mode 100644
index 0000000000..5aa1c9679c
--- /dev/null
+++ b/testing/btest/Files/mmdb/go.mod
@@ -0,0 +1,11 @@
+module testmmdb
+
+go 1.21.0
+
+require github.com/maxmind/mmdbwriter v1.0.0
+
+require (
+	github.com/oschwald/maxminddb-golang v1.12.0 // indirect
+	go4.org/netipx v0.0.0-20220812043211-3cc044ffd68d // indirect
+	golang.org/x/sys v0.10.0 // indirect
+)
diff --git a/testing/btest/Files/mmdb/go.sum b/testing/btest/Files/mmdb/go.sum
new file mode 100644
index 0000000000..a7e4aa9667
--- /dev/null
+++ b/testing/btest/Files/mmdb/go.sum
@@ -0,0 +1,16 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/maxmind/mmdbwriter v1.0.0 h1:bieL4P6yaYaHvbtLSwnKtEvScUKKD6jcKaLiTM3WSMw=
+github.com/maxmind/mmdbwriter v1.0.0/go.mod h1:noBMCUtyN5PUQ4H8ikkOvGSHhzhLok51fON2hcrpKj8=
+github.com/oschwald/maxminddb-golang v1.12.0 h1:9FnTOD0YOhP7DGxGsq4glzpGy5+w7pq50AS6wALUMYs=
+github.com/oschwald/maxminddb-golang v1.12.0/go.mod h1:q0Nob5lTCqyQ8WT6FYgS1L7PXKVVbgiymefNwIjPzgY=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+go4.org/netipx v0.0.0-20220812043211-3cc044ffd68d h1:ggxwEf5eu0l8v+87VhX1czFh8zJul3hK16Gmruxn7hw=
+go4.org/netipx v0.0.0-20220812043211-3cc044ffd68d/go.mod h1:tgPU4N2u9RByaTN3NC2p9xOzyFpte4jYwsIIRF7XlSc=
+golang.org/x/sys v0.10.0 h1:SqMFp9UcQJZa+pmYuAKjd9xq1f0j5rLcDIk0mj4qAsA=
+golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/testing/btest/Files/mmdb/main.go b/testing/btest/Files/mmdb/main.go
new file mode 100644
index 0000000000..ecad3ea8db
--- /dev/null
+++ b/testing/btest/Files/mmdb/main.go
@@ -0,0 +1,71 @@
+// Create test MaxMind DB database files containing information about
+// just LBL's IPv4 ranges for testing.
+package main
+
+import (
+	"log"
+	"net"
+	"os"
+
+	"github.com/maxmind/mmdbwriter"
+	"github.com/maxmind/mmdbwriter/mmdbtype"
+)
+
+func writeDb(fname, name string, record mmdbtype.Map, nets ...*net.IPNet) {
+	writer, err := mmdbwriter.New(
+		mmdbwriter.Options{
+			DatabaseType: name,
+		},
+	)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, n := range nets {
+		if err = writer.Insert(n, record); err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	fh, err := os.Create(fname)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer fh.Close()
+
+	_, err = writer.WriteTo(fh)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func main() {
+	_, net1, _ := net.ParseCIDR("128.3.0.0/16")
+	_, net2, _ := net.ParseCIDR("131.243.0.0/16")
+
+	// The ASN record.
+	asn_record := mmdbtype.Map{}
+	asn_record["autonomous_system_number"] = mmdbtype.Uint32(16)
+	asn_record["autonomous_system_organization"] = mmdbtype.String("Lawrence Berkeley National Laboratory")
+	writeDb("GeoLite2-ASN.mmdb", "My-ASN-DB", asn_record, net1, net2)
+
+	// The Location record.
+	loc_record := mmdbtype.Map{
+		"country": mmdbtype.Map{
+			"iso_code": mmdbtype.String("US"),
+			"names": mmdbtype.Map{
+				"en": mmdbtype.String("United States"),
+			},
+		},
+		"location": mmdbtype.Map{
+			"latitude":  mmdbtype.Float64(37.75100),
+			"longitude": mmdbtype.Float64(-97.822000),
+		},
+		"city": mmdbtype.Map{
+			"names": mmdbtype.Map{
+				"en": mmdbtype.String("Berkeley"),
+			},
+		},
+	}
+	writeDb("GeoLite2-City.mmdb", "My-City-DB", loc_record, net1, net2)
+}