diff --git a/Lib/test/sha256.pem b/Lib/test/sha256.pem
index 01878e9..d488e6d 100644
--- a/Lib/test/sha256.pem
+++ b/Lib/test/sha256.pem
@@ -1,33 +1,129 @@
+# Certificate chain for https://sha256.tbs-internet.com
+ 0 s:/C=FR/postalCode=14000/ST=Calvados/L=CAEN/street=22 rue de Bretagne/O=TBS INTERNET/OU=0002 440443810/OU=sha-256 production/CN=sha256.tbs-internet.com
+   i:/C=FR/ST=Calvados/L=Caen/O=TBS INTERNET/OU=Terms and Conditions: http://www.tbs-internet.com/CA/repository/OU=TBS INTERNET CA/CN=TBS X509 CA SGC
 -----BEGIN CERTIFICATE-----
-MIIFxzCCA6+gAwIBAgIJALnlnf5uzTkIMA0GCSqGSIb3DQEBCwUAMEsxCzAJBgNV
-BAYTAkRFMRcwFQYDVQQKEw5zY2hva29rZWtzLm9yZzEjMCEGCSqGSIb3DQEJARYU
-aGFubm9Ac2Nob2tva2Vrcy5vcmcwHhcNMTAwMTI3MDAyMTI1WhcNMjAwMTI1MDAy
-MTI1WjBLMQswCQYDVQQGEwJERTEXMBUGA1UEChMOc2Nob2tva2Vrcy5vcmcxIzAh
-BgkqhkiG9w0BCQEWFGhhbm5vQHNjaG9rb2tla3Mub3JnMIICIjANBgkqhkiG9w0B
-AQEFAAOCAg8AMIICCgKCAgEApJ4ODPwEooMW35dQPlBqdvcfkEvjhcsA7jmJfFqN
-e/1T34zT44X9+KnMBSG2InacbD7eyFgjfaENFsZ87YkEBDIFZ/SHotLJZORQ8PUj
-YoxPG4mjKN+yL2WthNcYbRyJreTbbDroNMuw6tkTSxeSXyYFQrKMCUfErVbZa/d5
-RvfFVk+Au9dVUFhed/Stn5cv+a0ffvpyA7ygihm1kMFICbvPeI0846tmC2Ph7rM5
-pYQyNBDOVpULODTk5Wu6jiiJJygvJWCZ1FdpsdBs5aKWHWdRhX++quGuflTTjH5d
-qaIka4op9H7XksYphTDXmV+qHnva5jbPogwutDQcVsGBQcJaLmQqhsQK13bf4khE
-iWJvfBLfHn8OOpY25ZwwuigJIwifNCxQeeT1FrLmyuYNhz2phPpzx065kqSUSR+A
-Iw8DPE6e65UqMDKqZnID3dQeiQaFrHEV+Ibo0U/tD0YSBw5p33TMh0Es33IBWMac
-m7x4hIFWdhl8W522u6qOrTswY3s8vB7blNWqMc9n7oWH8ybFf7EgKeDVtEN9AyBE
-0WotXIEZWI+WvDbU1ACJXau9sQhYP/eerg7Zwr3iGUy4IQ5oUJibnjtcE+z8zmDN
-pE6YcMCLJyLjXiQ3iHG9mNXzw7wPnslTbEEEukrfSlHGgW8Dm+VrNyW0JUM1bntx
-vbMCAwEAAaOBrTCBqjAdBgNVHQ4EFgQUCedv7pDTuXtCxm4HTw9hUtrTvsowewYD
-VR0jBHQwcoAUCedv7pDTuXtCxm4HTw9hUtrTvsqhT6RNMEsxCzAJBgNVBAYTAkRF
-MRcwFQYDVQQKEw5zY2hva29rZWtzLm9yZzEjMCEGCSqGSIb3DQEJARYUaGFubm9A
-c2Nob2tva2Vrcy5vcmeCCQC55Z3+bs05CDAMBgNVHRMEBTADAQH/MA0GCSqGSIb3
-DQEBCwUAA4ICAQBHKAxA7WA/MEFjet03K8ouzEOr6Jrk2fZOuRhoDZ+9gr4FtaJB
-P3Hh5D00kuSOvDnwsvCohxeNd1KTMAwVmVoH+NZkHERn3UXniUENlp18koI1ehlr
-CZbXbzzE9Te9BelliSFA63q0cq0yJN1x9GyabU34XkAouCAmOqfSpKNZWZHGBHPF
-bbYnZrHEMcsye6vKeTOcg1GqUHGrQM2WK0QaOwnCQv2RblI9VN+SeRoUJ44qTXdW
-TwIYStsIPesacNcAQTStnHgKqIPx4zCwdx5xo8zONbXJfocqwyFqiAofvb9dN1nW
-g1noVBcXB+oRBZW5CjFw87U88itq39i9+BWl835DWLBW2pVmx1QTLGv0RNgs/xVx
-mWnjH4nNHvrjn6pRmqHZTk/SS0Hkl2qtDsynVxIl8EiMTfWSU3DBTuD2J/RSzuOE
-eKtAbaoXkXE31jCl4FEZLITIZd8UkXacb9rN304tAK92L76JOAV+xOZxFRipmvx4
-+A9qQXgLhtP4VaDajb44V/kCKPSA0Vm3apehke9Wl8dDtagfos1e6MxSu3EVLXRF
-SP2U777V77pdMSd0f/7cerKn5FjrxW1v1FaP1oIGniMk4qQNTgA/jvvhjybsPlVA
-jsfnhWGbh1voJa0RQcMiRMsxpw2P1KNOEu37W2eq/vFghVztZJQUmb5iNw==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+-----END CERTIFICATE-----
+ 1 s:/C=FR/ST=Calvados/L=Caen/O=TBS INTERNET/OU=Terms and Conditions: http://www.tbs-internet.com/CA/repository/OU=TBS INTERNET CA/CN=TBS X509 CA SGC
+   i:/C=SE/O=AddTrust AB/OU=AddTrust External TTP Network/CN=AddTrust External CA Root
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
+ 2 s:/C=SE/O=AddTrust AB/OU=AddTrust External TTP Network/CN=AddTrust External CA Root
+   i:/C=US/ST=UT/L=Salt Lake City/O=The USERTRUST Network/OU=http://www.usertrust.com/CN=UTN - DATACorp SGC
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
+ 3 s:/C=US/ST=UT/L=Salt Lake City/O=The USERTRUST Network/OU=http://www.usertrust.com/CN=UTN - DATACorp SGC
+   i:/C=US/ST=UT/L=Salt Lake City/O=The USERTRUST Network/OU=http://www.usertrust.com/CN=UTN - DATACorp SGC
+-----BEGIN CERTIFICATE-----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 -----END CERTIFICATE-----
diff --git a/Lib/test/support.py b/Lib/test/support.py
index 3353053..5dd8017 100644
--- a/Lib/test/support.py
+++ b/Lib/test/support.py
@@ -623,6 +623,7 @@
     default_errnos = [
         ('ECONNREFUSED', 111),
         ('ECONNRESET', 104),
+        ('EHOSTUNREACH', 113),
         ('ENETUNREACH', 101),
         ('ETIMEDOUT', 110),
     ]
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
index 38ad140..bb38890 100644
--- a/Lib/test/test_ssl.py
+++ b/Lib/test/test_ssl.py
@@ -228,7 +228,7 @@
         # NOTE: https://sha256.tbs-internet.com is another possible test host
         remote = ("sha2.hboeck.de", 443)
         sha256_cert = os.path.join(os.path.dirname(__file__), "sha256.pem")
-        with support.transient_internet("sha2.hboeck.de"):
+        with support.transient_internet("sha256.tbs-internet.com"):
             s = ssl.wrap_socket(socket.socket(socket.AF_INET),
                                 cert_reqs=ssl.CERT_REQUIRED,
                                 ca_certs=sha256_cert,)