diff --git a/changelog.d/6811.bugfix b/changelog.d/6811.bugfix
new file mode 100644
index 000000000000..361f2fc2e816
--- /dev/null
+++ b/changelog.d/6811.bugfix
@@ -0,0 +1 @@
+Fix waking up other workers when remote server is detected to have come back online.
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index 198257414b3f..dc563538deb6 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -15,6 +15,7 @@
 # limitations under the License.
 
 import logging
+from typing import Any, Dict
 
 from six.moves import urllib
 
@@ -352,7 +353,9 @@ def get_public_rooms(
         else:
             path = _create_v1_path("/publicRooms")
 
-            args = {"include_all_networks": "true" if include_all_networks else "false"}
+            args = {
+                "include_all_networks": "true" if include_all_networks else "false"
+            }  # type: Dict[str, Any]
             if third_party_instance_id:
                 args["third_party_instance_id"] = (third_party_instance_id,)
             if limit:
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index d8cf9ed299f6..125eadd796ef 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -18,6 +18,7 @@
 import functools
 import logging
 import re
+from typing import Optional, Tuple, Type
 
 from twisted.internet.defer import maybeDeferred
 
@@ -267,6 +268,8 @@ class BaseFederationServlet(object):
                 returned.
     """
 
+    PATH = ""  # Overridden in subclasses, the regex to match against the path.
+
     REQUIRE_AUTH = True
 
     PREFIX = FEDERATION_V1_PREFIX  # Allows specifying the API version
@@ -347,9 +350,6 @@ async def new_func(request, *args, **kwargs):
 
             return response
 
-        # Extra logic that functools.wraps() doesn't finish
-        new_func.__self__ = func.__self__
-
         return new_func
 
     def register(self, server):
@@ -824,7 +824,7 @@ async def on_POST(self, origin, content, query):
         if not self.allow_access:
             raise FederationDeniedError(origin)
 
-        limit = int(content.get("limit", 100))
+        limit = int(content.get("limit", 100))  # type: Optional[int]
         since_token = content.get("since", None)
         search_filter = content.get("filter", None)
 
@@ -971,7 +971,7 @@ async def on_POST(self, origin, content, query, group_id, room_id, config_key):
         if get_domain_from_id(requester_user_id) != origin:
             raise SynapseError(403, "requester_user_id doesn't match origin")
 
-        result = await self.groups_handler.update_room_in_group(
+        result = await self.handler.update_room_in_group(
             group_id, requester_user_id, room_id, config_key, content
         )
 
@@ -1422,11 +1422,13 @@ async def on_GET(self, origin, content, query, room_id):
     On3pidBindServlet,
     FederationVersionServlet,
     RoomComplexityServlet,
-)
+)  # type: Tuple[Type[BaseFederationServlet], ...]
 
-OPENID_SERVLET_CLASSES = (OpenIdUserInfo,)
+OPENID_SERVLET_CLASSES = (
+    OpenIdUserInfo,
+)  # type: Tuple[Type[BaseFederationServlet], ...]
 
-ROOM_LIST_CLASSES = (PublicRoomList,)
+ROOM_LIST_CLASSES = (PublicRoomList,)  # type: Tuple[Type[PublicRoomList], ...]
 
 GROUP_SERVER_SERVLET_CLASSES = (
     FederationGroupsProfileServlet,
@@ -1447,17 +1449,19 @@ async def on_GET(self, origin, content, query, room_id):
     FederationGroupsAddRoomsServlet,
     FederationGroupsAddRoomsConfigServlet,
     FederationGroupsSettingJoinPolicyServlet,
-)
+)  # type: Tuple[Type[BaseFederationServlet], ...]
 
 
 GROUP_LOCAL_SERVLET_CLASSES = (
     FederationGroupsLocalInviteServlet,
     FederationGroupsRemoveLocalUserServlet,
     FederationGroupsBulkPublicisedServlet,
-)
+)  # type: Tuple[Type[BaseFederationServlet], ...]
 
 
-GROUP_ATTESTATION_SERVLET_CLASSES = (FederationGroupsRenewAttestaionServlet,)
+GROUP_ATTESTATION_SERVLET_CLASSES = (
+    FederationGroupsRenewAttestaionServlet,
+)  # type: Tuple[Type[BaseFederationServlet], ...]
 
 DEFAULT_SERVLET_GROUPS = (
     "federation",
diff --git a/synapse/replication/tcp/client.py b/synapse/replication/tcp/client.py
index fc06a7b0536d..02ab5b66eab7 100644
--- a/synapse/replication/tcp/client.py
+++ b/synapse/replication/tcp/client.py
@@ -31,6 +31,7 @@
     Command,
     FederationAckCommand,
     InvalidateCacheCommand,
+    RemoteServerUpCommand,
     RemovePusherCommand,
     UserIpCommand,
     UserSyncCommand,
@@ -210,6 +211,9 @@ def send_user_ip(self, user_id, access_token, ip, user_agent, device_id, last_se
         cmd = UserIpCommand(user_id, access_token, ip, user_agent, device_id, last_seen)
         self.send_command(cmd)
 
+    def send_remote_server_up(self, server: str):
+        self.send_command(RemoteServerUpCommand(server))
+
     def await_sync(self, data):
         """Returns a deferred that is resolved when we receive a SYNC command
         with given data.
diff --git a/synapse/server.pyi b/synapse/server.pyi
index 07314030473a..90347ac23eb0 100644
--- a/synapse/server.pyi
+++ b/synapse/server.pyi
@@ -2,8 +2,8 @@ import twisted.internet
 
 import synapse.api.auth
 import synapse.config.homeserver
+import synapse.crypto.keyring
 import synapse.federation.sender
-import synapse.federation.transaction_queue
 import synapse.federation.transport.client
 import synapse.handlers
 import synapse.handlers.auth
@@ -17,6 +17,7 @@ import synapse.handlers.room_member
 import synapse.handlers.set_password
 import synapse.http.client
 import synapse.notifier
+import synapse.replication.tcp.client
 import synapse.rest.media.v1.media_repository
 import synapse.server_notices.server_notices_manager
 import synapse.server_notices.server_notices_sender
@@ -27,6 +28,9 @@ class HomeServer(object):
     @property
     def config(self) -> synapse.config.homeserver.HomeServerConfig:
         pass
+    @property
+    def hostname(self) -> str:
+        pass
     def get_auth(self) -> synapse.api.auth.Auth:
         pass
     def get_auth_handler(self) -> synapse.handlers.auth.AuthHandler:
@@ -97,3 +101,9 @@ class HomeServer(object):
         pass
     def get_reactor(self) -> twisted.internet.base.ReactorBase:
         pass
+    def get_keyring(self) -> synapse.crypto.keyring.Keyring:
+        pass
+    def get_tcp_replication(
+        self,
+    ) -> synapse.replication.tcp.client.ReplicationClientHandler:
+        pass
diff --git a/tox.ini b/tox.ini
index 1d946a02ba74..88ef12bebd32 100644
--- a/tox.ini
+++ b/tox.ini
@@ -179,6 +179,7 @@ extras = all
 commands = mypy \
             synapse/api \
             synapse/config/ \
+            synapse/federation/transport \
             synapse/handlers/ui_auth \
             synapse/logging/ \
             synapse/module_api \