diff --git a/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Driver.c b/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Driver.c
index b3a877c9ef..18be21846d 100644
--- a/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Driver.c
+++ b/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Driver.c
@@ -297,6 +297,7 @@ Ip4CreateService (
     //
     IpSb->MaxPacketSize -= NET_VLAN_TAG_LEN;
   }
+  IpSb->OldMaxPacketSize = IpSb->MaxPacketSize;
   IpSb->MacString = NULL;
 
   *Service = IpSb;
diff --git a/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Input.c b/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Input.c
index d888e18e4c..75333b82ef 100644
--- a/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Input.c
+++ b/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Input.c
@@ -510,20 +510,11 @@ Ip4IpSecProcessPacket (
   
   if (mIpSec == NULL) {
     gBS->LocateProtocol (&gEfiIpSecProtocolGuid, NULL, (VOID **) &mIpSec);
-    if (mIpSec != NULL) {
-      //
-      // Save the original MTU
-      //
-      IpSb->OldMaxPacketSize = IpSb->MaxPacketSize; 
+    if (mIpSec == NULL) {
+      goto ON_EXIT;
     }
   }
 
-  //
-  // Check whether the IPsec protocol is available.
-  //
-  if (mIpSec == NULL) {
-    goto ON_EXIT;
-  }
   //
   // Check whether the IPsec enable variable is set.
   //