diff --git a/test/case/ietf_interfaces/lag_basic/test.py b/test/case/ietf_interfaces/lag_basic/test.py
index 9cbd0d25..7bb01045 100755
--- a/test/case/ietf_interfaces/lag_basic/test.py
+++ b/test/case/ietf_interfaces/lag_basic/test.py
@@ -14,9 +14,9 @@ each test step using the `mon` interface.
 from time import sleep, time
 from datetime import datetime
 import infamy
+import infamy.lag
 from infamy.util import parallel, until
 
-
 class DumbLinkBreaker:
     """Encapsulates basic, dumb link-breaking ops over SSH."""
 
@@ -135,7 +135,7 @@ def dut_init(dut, mode, addr):
 
 with infamy.Test() as test:
     with test.step("Set up topology and attach to target DUTs"):
-        env = infamy.Env()
+        env = infamy.Env(edge_mappings=infamy.lag.edge_mappings)
         dut1 = env.attach("dut1", "mgmt")
         dut2 = env.attach("dut2", "mgmt")
 
diff --git a/test/case/ietf_interfaces/lag_basic/topology.dot b/test/case/ietf_interfaces/lag_basic/topology.dot
index 9715914e..b8b7e3ff 100644
--- a/test/case/ietf_interfaces/lag_basic/topology.dot
+++ b/test/case/ietf_interfaces/lag_basic/topology.dot
@@ -28,6 +28,6 @@ graph "lag" {
     host:mon   -- dut1:mon  // Monitor connection to dut2 via dut1
     host:mgmt2 -- dut2:mgmt [requires="mgmt", color=lightgrey]
 
-    dut1:link1 -- dut2:link1 [color=black, fontcolor=black, penwidth=3]
-    dut1:link2 -- dut2:link2 [color=black, fontcolor=black, penwidth=3]
+    dut1:link1 -- dut2:link1 [lag=true, color=black, fontcolor=black, penwidth=3]
+    dut1:link2 -- dut2:link2 [lag=true, color=black, fontcolor=black, penwidth=3]
 }
diff --git a/test/case/ietf_interfaces/lag_failure/test.py b/test/case/ietf_interfaces/lag_failure/test.py
index 315c2236..a5ee002b 100755
--- a/test/case/ietf_interfaces/lag_failure/test.py
+++ b/test/case/ietf_interfaces/lag_failure/test.py
@@ -13,6 +13,7 @@ each failure mode step using the `mon` interface.
 """
 from time import time
 import infamy
+import infamy.lag
 from infamy.netns import TPMR
 from infamy.util import parallel
 
@@ -120,7 +121,7 @@ def dut_init(dut, addr, peer):
 
 with infamy.Test() as test:
     with test.step("Set up topology and attach to target DUTs"):
-        env = infamy.Env()
+        env = infamy.Env(edge_mappings=infamy.lag.edge_mappings)
         dut1 = env.attach("dut1")
         dut2 = env.attach("dut2")
 
diff --git a/test/case/ietf_interfaces/lag_failure/topology.dot b/test/case/ietf_interfaces/lag_failure/topology.dot
index 8b24b884..38ca7b55 100644
--- a/test/case/ietf_interfaces/lag_failure/topology.dot
+++ b/test/case/ietf_interfaces/lag_failure/topology.dot
@@ -28,9 +28,9 @@ graph "lag" {
     host:mon   -- dut1:mon  // Monitor connection to dut2 via dut1
     host:mgmt2 -- dut2:mgmt [requires="mgmt", color=lightgrey]
 
-    dut1:link1 -- host:lb1a  [requires="ieee-mc", color=black, fontcolor=black]
-    host:lb1b  -- dut2:link1 [requires="ieee-mc", color=black, fontcolor=black]
+    dut1:link1 -- host:lb1a  [requires="ieee-mc", lag=true, color=black, fontcolor=black]
+    host:lb1b  -- dut2:link1 [requires="ieee-mc", lag=true, color=black, fontcolor=black]
 
-    dut1:link2 -- host:lb2a  [requires="ieee-mc", color=black, fontcolor=black]
-    host:lb2b  -- dut2:link2 [requires="ieee-mc", color=black, fontcolor=black]
+    dut1:link2 -- host:lb2a  [requires="ieee-mc", lag=true, color=black, fontcolor=black]
+    host:lb2b  -- dut2:link2 [requires="ieee-mc", lag=true, color=black, fontcolor=black]
 }
diff --git a/test/infamy/lag.py b/test/infamy/lag.py
new file mode 100644
index 00000000..7a2cf5b1
--- /dev/null
+++ b/test/infamy/lag.py
@@ -0,0 +1,26 @@
+from . import topology
+
+def edge_mappings(les, pes):
+    """Specialized topology edge mapper for LAG tests
+
+    In addition to the standard provides/requires validation, ensure
+    that for all logical ports marked with a "lag" attribute, the
+    corresponding physical ports are all of the same link type
+    (e.g. "link-10gbase-r").
+
+    """
+    def links_compatible(candidate):
+        seen = None
+        for (le, pe) in candidate:
+            if le.get("lag"):
+                link = set(filter(lambda f: f.startswith("link-"), pe["provides"]))
+                if seen is None:
+                    seen = link
+                elif link != seen:
+                    return False
+
+        return True
+
+    for candidate in topology.edge_mappings(les, pes):
+        if links_compatible(candidate):
+            yield candidate