diff --git a/data/grid5000/sites/nancy/network_equipments/sgraphene1.json b/data/grid5000/sites/nancy/network_equipments/sgraphene1.json
index 2d9e2cad8b9a865ce18f920e6e3cb025204e107e..990e942da31a2bf7bdb446692ab80192361ee77a 100644
--- a/data/grid5000/sites/nancy/network_equipments/sgraphene1.json
+++ b/data/grid5000/sites/nancy/network_equipments/sgraphene1.json
@@ -153,7 +153,7 @@
     }
   ],
   "model": "3com 4510G",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/data/grid5000/sites/nancy/network_equipments/sgraphene2.json b/data/grid5000/sites/nancy/network_equipments/sgraphene2.json
index d9b3bdbbc59caa0018954aada8f4f48a5f7fe2be..66fd11d96be300442f0fb509d0899ac7c2c6c969 100644
--- a/data/grid5000/sites/nancy/network_equipments/sgraphene2.json
+++ b/data/grid5000/sites/nancy/network_equipments/sgraphene2.json
@@ -138,7 +138,7 @@
     }
   ],
   "model": "3com 4510G",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/data/grid5000/sites/nancy/network_equipments/sgraphene3.json b/data/grid5000/sites/nancy/network_equipments/sgraphene3.json
index 260746ae829ecd1cc913a4753c84beea50e90c65..81bda9d71075b9e647d8a8e168f9db1f612224b5 100644
--- a/data/grid5000/sites/nancy/network_equipments/sgraphene3.json
+++ b/data/grid5000/sites/nancy/network_equipments/sgraphene3.json
@@ -123,7 +123,7 @@
     }
   ],
   "model": "3com 4510G",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/data/grid5000/sites/nancy/network_equipments/sgraphene4.json b/data/grid5000/sites/nancy/network_equipments/sgraphene4.json
index 05456a5ac3de6ebaf8dec951ce36411345e691d6..3eb0ae02138f5c2af750ed46611447d04df48fba 100644
--- a/data/grid5000/sites/nancy/network_equipments/sgraphene4.json
+++ b/data/grid5000/sites/nancy/network_equipments/sgraphene4.json
@@ -150,7 +150,7 @@
     }
   ],
   "model": "3com 4510G",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/data/grid5000/sites/nancy/network_equipments/sgriffon1.json b/data/grid5000/sites/nancy/network_equipments/sgriffon1.json
index 0ca5dbedd7f6c6410d1e86551067d542c54de4c5..e99b7e0a8b407ef3c72e8ad12b8705c960c555cc 100644
--- a/data/grid5000/sites/nancy/network_equipments/sgriffon1.json
+++ b/data/grid5000/sites/nancy/network_equipments/sgriffon1.json
@@ -162,7 +162,7 @@
     }
   ],
   "model": "3com 4500g",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/data/grid5000/sites/nancy/network_equipments/sgriffon2.json b/data/grid5000/sites/nancy/network_equipments/sgriffon2.json
index d64dfdc3002fa17a9733e245992b1f09b80adf4b..ce2a6071b66ad47c661e2a35008a5210916b29e8 100644
--- a/data/grid5000/sites/nancy/network_equipments/sgriffon2.json
+++ b/data/grid5000/sites/nancy/network_equipments/sgriffon2.json
@@ -159,7 +159,7 @@
     }
   ],
   "model": "3com 4500g",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/data/grid5000/sites/nancy/network_equipments/sgriffon3.json b/data/grid5000/sites/nancy/network_equipments/sgriffon3.json
index 550b4009f411f9ce8bce495ec3e31449478b204b..8f97b0aa388c7c01bccfe3256a244213b1f2948d 100644
--- a/data/grid5000/sites/nancy/network_equipments/sgriffon3.json
+++ b/data/grid5000/sites/nancy/network_equipments/sgriffon3.json
@@ -162,7 +162,7 @@
     }
   ],
   "model": "3com 4500g",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/data/grid5000/sites/nancy/network_equipments/stalc1.json b/data/grid5000/sites/nancy/network_equipments/stalc1.json
index 5f5032fd99879f2f7d161bad60444e3a3a8e1c93..dda7e866ee0221d4e06fb09c1a62322d31265f55 100644
--- a/data/grid5000/sites/nancy/network_equipments/stalc1.json
+++ b/data/grid5000/sites/nancy/network_equipments/stalc1.json
@@ -181,7 +181,7 @@
     }
   ],
   "model": "3com 4500G",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/data/grid5000/sites/nancy/network_equipments/stalc2.json b/data/grid5000/sites/nancy/network_equipments/stalc2.json
index 16775448abd61c793bdb40b53e26ddad8ceedaf6..cf60b4f9401b5ccc296110833ff0ead73ae34b88 100644
--- a/data/grid5000/sites/nancy/network_equipments/stalc2.json
+++ b/data/grid5000/sites/nancy/network_equipments/stalc2.json
@@ -179,7 +179,7 @@
     }
   ],
   "model": "3com 4500G",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/data/grid5000/sites/nancy/network_equipments/stalc3.json b/data/grid5000/sites/nancy/network_equipments/stalc3.json
index 9f16a45ff4ca19f84f1618128b78600474efaa34..d045e71d902cd03b602fab00a206a5ebde632fe4 100644
--- a/data/grid5000/sites/nancy/network_equipments/stalc3.json
+++ b/data/grid5000/sites/nancy/network_equipments/stalc3.json
@@ -159,7 +159,7 @@
     }
   ],
   "model": "3com 4500G",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/data/grid5000/sites/nancy/network_equipments/stalc4.json b/data/grid5000/sites/nancy/network_equipments/stalc4.json
index 7c05c50a8138b6cae0c44c4afa78cca720ea4e71..4be673683f084c204e874531079ed9a8f004b63a 100644
--- a/data/grid5000/sites/nancy/network_equipments/stalc4.json
+++ b/data/grid5000/sites/nancy/network_equipments/stalc4.json
@@ -129,7 +129,7 @@
     }
   ],
   "model": "3com 4500G",
-  "mtu": null,
+  "mtu": 9216,
   "routes": {
 
   },
diff --git a/generators/input/sites/nancy/net-links/sgraphene1.yaml b/generators/input/sites/nancy/net-links/sgraphene1.yaml
index d7e2b9e65ff56bf51c2fbdf5ba918acbf1ff2172..1633e7c17be45645180f9fdc3cfaa5f1043865a2 100644
--- a/generators/input/sites/nancy/net-links/sgraphene1.yaml
+++ b/generators/input/sites/nancy/net-links/sgraphene1.yaml
@@ -4,6 +4,7 @@ sgraphene1:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan-interface%VLANID%
     "vlan1":
diff --git a/generators/input/sites/nancy/net-links/sgraphene2.yaml b/generators/input/sites/nancy/net-links/sgraphene2.yaml
index 39f3f274632b53652d4c5e8d7ef8d847dfb039e3..a33b533c760410d20d348f55776a5ab80a61d882 100644
--- a/generators/input/sites/nancy/net-links/sgraphene2.yaml
+++ b/generators/input/sites/nancy/net-links/sgraphene2.yaml
@@ -4,6 +4,7 @@ sgraphene2:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan-interface%VLANID%
     "vlan1":
diff --git a/generators/input/sites/nancy/net-links/sgraphene3.yaml b/generators/input/sites/nancy/net-links/sgraphene3.yaml
index d6814a5803ab649a3345ecbfcafd7263dfd6ac3a..5f8bceaca00999c8beaa926c92d8d37bca439cce 100644
--- a/generators/input/sites/nancy/net-links/sgraphene3.yaml
+++ b/generators/input/sites/nancy/net-links/sgraphene3.yaml
@@ -4,6 +4,7 @@ sgraphene3:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan-interface%VLANID%
     "vlan1":
diff --git a/generators/input/sites/nancy/net-links/sgraphene4.yaml b/generators/input/sites/nancy/net-links/sgraphene4.yaml
index 0a76ee6c374e4407c709f7373aa1c0a404ad7f8f..5946b6ba92f5d531586870e4bd7896fc5bd1b45f 100644
--- a/generators/input/sites/nancy/net-links/sgraphene4.yaml
+++ b/generators/input/sites/nancy/net-links/sgraphene4.yaml
@@ -4,6 +4,7 @@ sgraphene4:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan-interface%VLANID%
     "vlan1":
diff --git a/generators/input/sites/nancy/net-links/sgriffon1.yaml b/generators/input/sites/nancy/net-links/sgriffon1.yaml
index 2ac8db29c2dcfaaa9ae7644e318cf1b71d6e71f5..7d96dba7e551ed6e46a5ef897116aa979e1a865c 100644
--- a/generators/input/sites/nancy/net-links/sgriffon1.yaml
+++ b/generators/input/sites/nancy/net-links/sgriffon1.yaml
@@ -4,6 +4,7 @@ sgriffon1:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan-interface%VLANID%
     "vlan1":
diff --git a/generators/input/sites/nancy/net-links/sgriffon2.yaml b/generators/input/sites/nancy/net-links/sgriffon2.yaml
index adf340e9967f637959b826086c37e7a8c7bbb494..01752e502c25d8c47cf84a883d1037c228bcdf1d 100644
--- a/generators/input/sites/nancy/net-links/sgriffon2.yaml
+++ b/generators/input/sites/nancy/net-links/sgriffon2.yaml
@@ -4,6 +4,7 @@ sgriffon2:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan-interface%VLANID%
     "vlan1":
diff --git a/generators/input/sites/nancy/net-links/sgriffon3.yaml b/generators/input/sites/nancy/net-links/sgriffon3.yaml
index e5b0cb669c842d4f5115a8a0d561f6ba795f089d..da96dad5b312ef0b7de362710e2e7419deb5c07b 100644
--- a/generators/input/sites/nancy/net-links/sgriffon3.yaml
+++ b/generators/input/sites/nancy/net-links/sgriffon3.yaml
@@ -4,6 +4,7 @@ sgriffon3:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan-interface%VLANID%
     "vlan1":
diff --git a/generators/input/sites/nancy/net-links/stalc1.yaml b/generators/input/sites/nancy/net-links/stalc1.yaml
index 1e281b5c541052415d4df29c80171e3270b16842..77a66403b862b80ad29f6bd5ccc1eb64086d7530 100644
--- a/generators/input/sites/nancy/net-links/stalc1.yaml
+++ b/generators/input/sites/nancy/net-links/stalc1.yaml
@@ -4,6 +4,7 @@ stalc1:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan-interface%VLANID%
     "vlan1":
diff --git a/generators/input/sites/nancy/net-links/stalc2.yaml b/generators/input/sites/nancy/net-links/stalc2.yaml
index ee102c1539b7989469a113802e535e3ea9c96a2f..9d8afd9cb7b1de04791987c7e58d990bc827fe7d 100644
--- a/generators/input/sites/nancy/net-links/stalc2.yaml
+++ b/generators/input/sites/nancy/net-links/stalc2.yaml
@@ -4,6 +4,7 @@ stalc2:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan-interface%VLANID%
     "vlan1":
diff --git a/generators/input/sites/nancy/net-links/stalc3.yaml b/generators/input/sites/nancy/net-links/stalc3.yaml
index 6b6309e270e3e9a0499a268b32dd05ef623ef0d6..19318419e921dd51b182c4045575a8c91308d114 100644
--- a/generators/input/sites/nancy/net-links/stalc3.yaml
+++ b/generators/input/sites/nancy/net-links/stalc3.yaml
@@ -4,6 +4,7 @@ stalc3:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan-interface%VLANID%
     "vlan1":
diff --git a/generators/input/sites/nancy/net-links/stalc4.yaml b/generators/input/sites/nancy/net-links/stalc4.yaml
index d98fad5dec6ed9d8dd04a719a6475157e45abbc5..11a98335aa369d706d411c07b4fd6185e8b11913 100644
--- a/generators/input/sites/nancy/net-links/stalc4.yaml
+++ b/generators/input/sites/nancy/net-links/stalc4.yaml
@@ -4,6 +4,7 @@ stalc4:
   kind: switch
   site: nancy
   snmp_community: public
+  mtu: 9216
   vlans:
     naming_pattern: Vlan%VLANID%
     "vlan100":