diff --git a/neutron/common/exceptions.py b/neutron/common/exceptions.py
index 68c73f50bb..63ff13894d 100644
--- a/neutron/common/exceptions.py
+++ b/neutron/common/exceptions.py
@@ -178,12 +178,6 @@ class NoNetworkAvailable(ResourceExhausted):
                 "No tenant network is available for allocation.")
 
 
-class AlreadyAttached(Conflict):
-    message = _("Unable to plug the attachment %(att_id)s into port "
-                "%(port_id)s for network %(net_id)s. The attachment is "
-                "already plugged into port %(att_port_id)s")
-
-
 class SubnetMismatchForPort(Conflict):
     message = _("Subnet on port %(port_id)s does not match "
                 "the requested subnet %(subnet_id)s")
diff --git a/neutron/plugins/nicira/common/exceptions.py b/neutron/plugins/nicira/common/exceptions.py
index c18102440f..0c34010406 100644
--- a/neutron/plugins/nicira/common/exceptions.py
+++ b/neutron/plugins/nicira/common/exceptions.py
@@ -48,12 +48,6 @@ class NvpNoMorePortsException(NvpPluginException):
                 "Maximum number of ports reached")
 
 
-class NvpPortAlreadyAttached(q_exc.Conflict):
-    message = _("Unable to plug an interface into the port %(port_id)s "
-                "for network %(net_id)s. This interface is already plugged "
-                "into port %(att_port_id)s")
-
-
 class NvpNatRuleMismatch(NvpPluginException):
     message = _("While retrieving NAT rules, %(actual_rules)s were found "
                 "whereas rules in the (%(min_rules)s,%(max_rules)s) interval "