Différences

Ci-dessous, les différences entre deux révisions de la page.

--- cours:bat4:netipws:ipudptcpsummary [2018/03/07 11:13] – [Internet and Transport Protocols : Key Ideas] tigli
+++ cours:bat4:netipws:ipudptcpsummary [2018/03/20 14:45] (Version actuelle) – [Internet Communications and Protocol : Key Ideas] tigli
@@ Ligne 11: / Ligne 11: @@
   * Routing table on each router provided a way to know which interface to use to send data to a give IP adress.
   * In such a hierarchy, every set of IP adresses consists in : a netid part and a hostid part : <netdid>|<hostid>
+|||
+|||
+{{:cours:bat4:netipws:capture_netid_subnetid_hostid.jpg?400 |}}
   * a subnet is a subset of adresses in this hierarchy : <netid>|<subnetid>|<hostid>
   * a network mask allows to specify the number of bits of the netid. All the bits corresponding to the netid are equal to 1 and the other to 0. Thus for 167.145.134.32/18 (the means 18 bits to code the netid), the mask is 255.255.192.0.
   * For each network, size of subnetid + size of hostid  = 32 - size of netid. Be careful, <netid>|0..0 and <netid>|1..1 are use respectively to indentify the corresponding network and the broadcast adress (to send data to all the interfaces of the <netid> network at the same time).
-  * So, for each network coded on k bits, a maximum of 2^(32-k-1) adresses are available for hosts.
+  * So, for each network coded on k bits, a maximum of 2^(32-k) - 2 adresses are available for hosts.
 === Exercices :  ===
   * How many interfaces has your PC ? (use ipconfig or ifconfig commands according to your OS : linus, MacOS, Windows)
-  * What is the IP adress for Wifi ? What is the mask of the corresponding network ? What is the list of IP adresses on this network ?
+  * What is the mask of the corresponding network ? What is the list of IP adresses on this network ?
 === Advanced Exercice : ===
@@ Ligne 27: / Ligne 33: @@
   * What are the different adresses of these networks ? their network mask ?
   * What maximum of host adresses can I set in each appartment ? (6)
-  * The router of the building is connected to ISDN optic fiber on the interface A (MAC address :
-====  Transport Protocols : Key Ideas ====
+=== Routing Table Example ===
-||
+  * The router of the building is connected to ISDN optic fiber on the interface A (MAC address : 00:11:22:33:44:55). The other interfaces are connected to separated ethernet networks :
-  * Because one internet interface can be used to send and receive multiple data simultaneously (from and for multiple software applications on a same interface of a smartphone, a PC, a TV ...), transport potocols are just above IP to dispatch these communications.
+     * Interface B : 01:2B:45:56:78:ED
-  * On each
+     * Interface C : 01:2B:45:22:88:AF
+     * Interface D : 01:2B:45:21:68:75
+     * Interface E : 01:2B:45:12:27:33
+     * Interface F : 01:2B:45:A4:34:28
+     * Interface G : 01:2B:45:11:18:27
+  * Each Interface B to G is obviously connected to each appartment.
+** The routing table of the router is then :  **
+|Interface|Mac Address|IP address of the network| Mask of the Nerwork|
+|A|00:11:22:33:44:55|Gateway*||
+|B|01:2B:45:56:78:ED|145.134.235.200|255.255.255.248|
+|C|01:2B:45:22:88:AF|145.134.235.208|255.255.255.248|
+|D|01:2B:45:21:68:75|145.134.235.216|255.255.255.248|
+|E|01:2B:45:12:27:33|145.134.235.224|255.255.255.248|
+|F|01:2B:45:A4:34:28|145.134.235.232|255.255.255.248|
+|G|01:2B:45:11:18:27|145.134.235.240|255.255.255.248|
+// ** (*) Gateway means all the other IP Addresses ...   ** //
+  * If you use route command (route -print on Windows), you can see the routing table of your computer .... a litle bit more complex, isn't it ?
+** Comments **
+  * using calc application on your PC in programmer mode (see upper left menu), try an AND operator between different hostids of different sunbets and the last byte of the mask ...
+  * Ex. : 203 AND 248, gives 200 ; 219 AND 248 gives 216.
+  * When you do same thing between 145.134.235.216 and 255.255.255.248 byte after byte what is the result? ... do you understand?
+  * This is the simplest operation to determine as quickly as possible which is the network the IP address belong to and what is the corresponding interface to use.
+=== ConceptDraw and Network Layout on the floor ===
+  * Each appartment is then equiped with a main Ethernet plug (on which we can plug a switch to distribute internet connection through ethernet to all the other ethernet plugs of the appartment.
+<note important>
+Everything is now defined  to design a Network Layout on the floors of the building with conceptdraw , isn't it ?
+</note>