diff --git a/test/case/infix_containers/container_bridge.py b/test/case/infix_containers/container_bridge.py
index 9e7f95b8..2b4caa95 100755
--- a/test/case/infix_containers/container_bridge.py
+++ b/test/case/infix_containers/container_bridge.py
@@ -89,15 +89,8 @@ with infamy.Test() as test:
         url = infamy.Furl(URL)
 
         with infamy.IsolatedMacVlan(hport) as ns:
-            connectivity = ns.runsh(f"""
-            ip link set iface up
-            ip addr add {OURIP}/24 dev iface
-
-            ping -c1 -w5 {DUTIP} || exit 1
-            """)
-            if connectivity.returncode:
-                print(connectivity.stdout)
-                test.fail()
+            ns.addip(OURIP)
+            ns.must_reach(DUTIP)
 
             until(lambda: url.nscheck(ns, "Kilroy was here"), attempts=10)
 
diff --git a/test/case/infix_containers/container_phys.py b/test/case/infix_containers/container_phys.py
index 51794b35..c4f4c576 100755
--- a/test/case/infix_containers/container_phys.py
+++ b/test/case/infix_containers/container_phys.py
@@ -68,15 +68,8 @@ with infamy.Test() as test:
         url = infamy.Furl(URL)
 
         with infamy.IsolatedMacVlan(hport) as ns:
-            connectivity = ns.runsh(f"""
-            ip link set iface up
-            ip addr add {OURIP}/24 dev iface
-
-            ping -c1 -w5 {DUTIP} || exit 1
-            """)
-            if connectivity.returncode:
-                print(connectivity.stdout)
-                test.fail()
+            ns.addip(OURIP)
+            ns.must_reach(DUTIP)
 
             until(lambda: url.nscheck(ns, "It works"), attempts=10)
 
diff --git a/test/case/infix_containers/container_veth.py b/test/case/infix_containers/container_veth.py
index 7f24143b..c6587b87 100755
--- a/test/case/infix_containers/container_veth.py
+++ b/test/case/infix_containers/container_veth.py
@@ -92,15 +92,8 @@ with infamy.Test() as test:
         url = infamy.Furl(URL)
 
         with infamy.IsolatedMacVlan(hport) as ns:
-            connectivity = ns.runsh(f"""
-            ip link set iface up
-            ip addr add {OURIP}/24 dev iface
-
-            ping -c1 -w5 {DUTIP} || exit 1
-            """)
-            if connectivity.returncode:
-                print(connectivity.stdout)
-                test.fail()
+            ns.addip(OURIP)
+            ns.must_reach(DUTIP)
 
             until(lambda: url.nscheck(ns, "It works"), attempts=10)