diff --git a/components/schemas/containers/config/ContainerNetwork.yml b/components/schemas/containers/config/ContainerNetwork.yml
index 51b85429..f40bdc31 100644
--- a/components/schemas/containers/config/ContainerNetwork.yml
+++ b/components/schemas/containers/config/ContainerNetwork.yml
@@ -24,7 +24,7 @@ properties:
       - "null"
     description: Custom network routes applied to the container's instances.
     items:
-      $ref: ./network/NetworkRoute.yml
+      $ref: ./network/NetworkRouteConfig.yml
   hostname:
     type: string
     description: The hostname for the given container.
diff --git a/components/schemas/containers/config/network/NetworkRoute.yml b/components/schemas/containers/config/network/NetworkRoute.yml
deleted file mode 100644
index 38d3ebcd..00000000
--- a/components/schemas/containers/config/network/NetworkRoute.yml
+++ /dev/null
@@ -1,18 +0,0 @@
-title: NetworkRoute
-type: object
-description: A single network route directing traffic for a destination network.
-required:
-  - destination
-  - gateway
-properties:
-  destination:
-    description: The destination network, in CIDR notation, that this route matches.
-    oneOf:
-      - $ref: ../../../Cidr.yml
-      - type: "null"
-  gateway:
-    description: The IP address that traffic matching the destination is forwarded to.
-    $ref: ../../../IpAddress.yml
-  interface:
-    type: string
-    description: The name of the network interface this route is bound to.
diff --git a/components/schemas/containers/config/network/NetworkRouteConfig.yml b/components/schemas/containers/config/network/NetworkRouteConfig.yml
new file mode 100644
index 00000000..680b08d4
--- /dev/null
+++ b/components/schemas/containers/config/network/NetworkRouteConfig.yml
@@ -0,0 +1,44 @@
+title: NetworkRouteConfig
+type: object
+description: A single network route directing traffic for a destination network.
+required:
+  - destination
+  - source
+  - ensure_source_exists
+  - gateway
+properties:
+  destination:
+    description: The destination network, in CIDR notation, that this route matches.
+    oneOf:
+      - $ref: ../../../Cidr.yml
+      - type: "null"
+  source:
+    description: >-
+      The source network, in CIDR notation, that this route applies to.
+    oneOf:
+      - $ref: ../../../Cidr.yml
+      - type: "null"
+  ensure_source_exists:
+    type: boolean
+    description: >-
+      When true, the source address is verified to exist on the host before
+      this route is applied.
+  family:
+    description: The IP protocol family this route applies to.
+    oneOf:
+      - type: string
+        enum:
+          - ipv4
+          - ipv6
+      - type: "null"
+  gateway:
+    description: The IP address that traffic matching the destination is forwarded to.
+    $ref: ../../../IpAddress.yml
+  nexthops:
+    type: array
+    description: Additional next hops for this route, used for multipath (ECMP) routing.
+    items:
+      $ref: ./NetworkRouteConfigNexthop.yml
+  interface:
+    type: string
+    description: The name of the network interface this route is bound to.
diff --git a/components/schemas/containers/config/network/NetworkRouteConfigNexthop.yml b/components/schemas/containers/config/network/NetworkRouteConfigNexthop.yml
new file mode 100644
index 00000000..94b80890
--- /dev/null
+++ b/components/schemas/containers/config/network/NetworkRouteConfigNexthop.yml
@@ -0,0 +1,17 @@
+title: NetworkRouteConfigNexthop
+type: object
+description: A single next hop for a multipath network route.
+required:
+  - gateway
+properties:
+  gateway:
+    description: The IP address of this next hop's gateway.
+    $ref: ../../../IpAddress.yml
+  hop_weight:
+    description: >-
+      The relative weight of this next hop when distributing traffic across
+      multiple next hops.
+    oneOf:
+      - type: integer
+        format: int64
+      - type: "null"
diff --git a/stackspec/schema/StackSpecContainerConfigNetwork.yml b/stackspec/schema/StackSpecContainerConfigNetwork.yml
index 271ff39c..2300505b 100644
--- a/stackspec/schema/StackSpecContainerConfigNetwork.yml
+++ b/stackspec/schema/StackSpecContainerConfigNetwork.yml
@@ -38,11 +38,61 @@ properties:
                 - $ref: ../../components/schemas/Cidr.yml
                 - type: "null"
                 - $ref: StackVariable.yml
+            source:
+              description: >-
+                The source network, in CIDR notation, that this route applies to.
+                Used for source-based (policy) routing.
+              oneOf:
+                - $ref: ../../components/schemas/Cidr.yml
+                - type: "null"
+                - $ref: StackVariable.yml
+            ensure_source_exists:
+              description: >-
+                When true, the source address is verified to exist on the host
+                before this route is applied.
+              oneOf:
+                - type: boolean
+                - $ref: StackVariable.yml
+            family:
+              description: The IP protocol family this route applies to.
+              oneOf:
+                - type: string
+                  enum:
+                    - ipv4
+                    - ipv6
+                - type: "null"
+                - $ref: StackVariable.yml
             gateway:
               description: The IP address that traffic matching the destination is forwarded to.
               oneOf:
                 - $ref: ../../components/schemas/IpAddress.yml
                 - $ref: StackVariable.yml
+            nexthops:
+              description: Additional next hops for this route, used for multipath routing.
+              oneOf:
+                - type: array
+                  items:
+                    title: NetworkRouteNexthop
+                    type: object
+                    description: A single next hop for a multipath network route.
+                    required:
+                      - gateway
+                    properties:
+                      gateway:
+                        description: The IP address of this next hop's gateway.
+                        oneOf:
+                          - $ref: ../../components/schemas/IpAddress.yml
+                          - $ref: StackVariable.yml
+                      hop_weight:
+                        description: >-
+                          The relative weight of this next hop when distributing
+                          traffic across multiple next hops.
+                        oneOf:
+                          - type: integer
+                            format: int64
+                          - type: "null"
+                          - $ref: StackVariable.yml
+                - $ref: StackVariable.yml
             interface:
               description: The name of the network interface this route is bound to.
               oneOf: