Lerouteur Raleigh est configuré avec la fonction PAT. Quelles sont les deux configurations à modifier si le réseau privé migre vers un réseau ? (Choisissez deux réponses.) L’adresse de l’interface E0 L’adresse de l’interface S0 L’instruction access-list L’interface NAT externe L’interface NAT interne . Constat Description Valeur maximum 1 correctness of response
CISCO ASA Basic Configuration Examples PAT Pre Old Config********************* Nat inside 1 global outside 1 interface Config - this configuration is called AUTO NAT Static and Global are gone Configuration Steps- Object network inside_net subnet nat inside,outside dynamic interface Dynamic will enable the PAT Show run Object *** will show the subnet Show Run NAT *** Will show the NATOne to One NAT translation Translate an Inside server IP address to an external Global IP address Configuration Steps- Object dmz_webserver host nat dmz,outside static this will enable one to one nat Access-list outside_in permit ip any host Use the inside real IP address not the Public IP, this feature is called REAL IP access-group outside_in in in out Show run Object *** will show the subnet Show Run NAT *** Will show the NATTranslating a single inside object between a multiple interfaces In You can define a translation for an object between a multiple interfaces in just one line. Configuration Steps- Object dmz_webserver host nat inside,any static this will enable access to from any interface Access-list outside_in permit ip any host Use the inside real IP address not the Public IP access-group outside_in in in outPAT for two inside server to one Global IP address Define two inside server to one external IP address with two different services DMZ host http server - FTP server - outside IP interface IP address Configuration Steps- Object network dmz-webserver Host Nat dmz,outside static interface service tcp www www Object network dmz-ftpserver Host Nat dmz,outside static interface service tcp ftp ftp Access-list outside_in permit tcp any host eq www Access-list outside_in permit tcp any host eq ftp access-group outside_in in in outManual NAT – TWICE NAT In Above Example - When an Inside single host access the .com it should be translated to for other traffic it should use an outside IP address using PAT. Configuration Steps- Object network translated-ip Host Object network cisco-dot-com Host Object network inside-net subnet nat inside,outside dynamic interface Dynamic will enable the PAT next create a manual NAT entry , configure it under base configuration mode not under an object inside,outside Source dynamic inside-net translated-ip destination static cisco-dot-com cisco-dot-com Show Run NAT *** Will show the NATPacket Tracer To trace the packet that will match the NAT translationTo check the Static manual NAT - packet-tracer input tcp 4444 80 Above shows the phase 5 NAT will translate the packets to To check the Auto NAT PAT - packet-tracer input tcp 4444 80 Above shows the phase 5 NAT will use auto NAT and translate the packets to – NO NAT - Policy NAT Exception Configure ASA to do not perform nat translations between the branch office and local networks Configuration Steps- Object network vpn-subnets Range Nat inside, outside source static inside-net inside-net destination static vpn-subnets vpn-subnets
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Ce tutoriel vous présente comment configurer un routeur Cisco. Cette configuration est celle de base, autrement dit, entre deux réseaux simplement. Livre complet sur la configuration du routeur Cisco Vous pouvez consulter la vidéo Ou le tutoriel écrit Mon réseau sera celui ci-dessous, donc d’un coté le réseau 1 en et de l’autre le réseau 2 en Ce test est réalisé sur Packet tracer car je n’avais pas de routeur Cisco physique sous la main mais les commandes sont les mêmes d’un routeur Cisco à l’autre. Pour le moment rien n’est configuré, même pas les deux PC, et pour communiquer entre les deux réseaux j’ai le routeur que je vais également devoir configurer. Dans un premier temps, je vais configurer le premier PC, je lui donne le nom de fafa-pc-1 Puis je configure son interface réseau. Je fais la même chose pour le second PC. Je tente un ping de la seconde machine sur la première, on ne sait jamais sur un malentendu. Comme prévu le ping échoue je ne peux pas communiquer avec l’autre réseau, normal le routeur n’est pas configuré. Le réseau ressemble à ceci pour le moment, les noms et interfaces réseaux des deux machines ont étés modifiés. Nous pouvons attaquer le routeur. Je me connecte sur le routeur, des informations m’attendent déjà. Je tape entrée pour que la console apparaisse, à partir de la je modifie le nom de routeur avec la commande hostname, je l’appelle rfafa. Je ne détaille pas les autres commandes qui permettent simplement de naviguer entre les modes du routeur. Maintenant je passe à la pratique, je vais configurer les mots de passes du routeur, par exemple quand je me connecte dessus. Je donne une bannière d’accueil à mon routeur. Ici se sera Bienvenue sur fafa-informatique » Je configure les deux interfaces réseaux du routeur, je fais bien attention à quel interface est sur quel réseau. Après chaque configuration d’interface je l’active avec la commande no shutdown. Mes interfaces sont prêtes. Je sauvegarde ma configuration, on ne sait jamais. Je vérifie que la configuration est bonne. La configuration du routeur apparaît, je peux la faire défiler avec entrée. Je vérifie les réseaux que connaît mon routeur. Je vérifie que les interfaces fonctionnent. Enfin, je vérifie en détail la configuration de mes interfaces. Je peux faire défiler les détail en appuyant sur entrée. En retournant sur mon réseau je constate immédiatement que les petits ronds sont désormais verts. Cela signifie que les connexions fonctionnent. Je vais néanmoins vérifier. Je ping depuis le PC fafa-pc-2 ayant pour IP vers l’interface réseau du routeur se situant dans son réseau. Le ping fonctionne parfaitement. Maintenant, je tente de pinger la machine sur l’autre réseau, ça fonctionne également. Nos deux réseaux peuvent donc communiquer. La première requête du ping n’est pas passée le temps qu’il trouve la route, mais toutes les requêtes passent. On le constate sur le deuxième ping. Ce tutoriel sur la configuration de base d’un routeur Cisco est maintenant terminé.
Step4: Remove the NAT translation from inside source list to outside pool. Gateway(config)# no ip nat inside source list 1 pool public_access overload Step 5: Associate the source list with the outside interface. Gateway(config)# ip nat inside source list 1 interface serial 0/0/1 overload Step 6: Test the PAT configuration. a. From each PC
Network address translation NAT is the process of modifying IP address information in IP packet headers while in transit across a traffic routing are two different types of NATNATStatic NAT The simplest type of NAT provides a one-to-one translation of IP addresses. It is often also referred to as one-to-one NAT. In this type of NAT only the IP addresses, IP header checksum and any higher level checksums that include the IP address need to be changed. The rest of the packet can be left untouched at least for basic TCP/UDP functionality, some higher level protocols may need further translation. Basic NATs can be used when there is a requirement to interconnect two IP networks with incompatible addressing. With static NAT, translations exist in the NAT translation table as soon as you configure static NAT commands, and they remain in the translation table until you delete the static NAT commands.Dynamic NAT Dynamic NAT has some similarities and differences compared to static NAT. Like static NAT, the NAT router creates a one-to-one mapping between an inside local and inside global address and changes the IP addresses in packets as they exit and enter the inside network. However, the mapping of an inside local address to an inside global address happens dynamically. Dynamic NAT sets up a pool of possible inside global addresses and defines matching criteria to determine which inside local IP addresses should be translated with NAT. The dynamic entry stays in the table as long as traffic flows occasionally. With dynamic NAT, translations do not exist in the NAT table until the router receives traffic that requires translation. Dynamic translations have a timeout period after which they are purged from the translation PAT Static PAT translations allow a specific UDP or TCP port on a global address to be translated to a specific port on a local address. Static PAT is the same as static NAT, except that it enables you to specify the protocol TCP or UDP and port for the real and mapped addresses. Static PAT enables you to identify the same mapped address across many different static statements, provided that the port is different for each statement. You cannot use the same mapped address for multiple static NAT statements. With static PAT, translations exist in the NAT translation table as soon as you configure static PAT commands, and they remain in the translation table until you delete the static PAT commands.NAT Overload or PAT It is common to hide an entire IP address space, usually consisting of private IP addresses, behind a single IP address or in some cases a small group of IP addresses in another usually public address space. This type of NAT is called PAT in overload. The dynamic entry stays in the table as long as traffic flows occasionally. With PAT in overload, translations do not exist in the NAT table until the router receives traffic that requires translation. Translations have a timeout period after which they are purged from the translation 1 Static Source NATHow to translate the IP address to the ip the ip nat insideCiscozineconfiginterface fa0/0 Ciscozineconfig-ifip nat insideDefine the ip nat outsideCiscozineconfiginterface fa0/1 Ciscozineconfig-ifip nat outsideDefine the static NAT entryip nat inside source static static NAT, translation exists in the NAT translation table as soon as you configure static NAT command, and it remains in the translation table until you delete the static NAT commandCiscozinesh ip nat translations Pro Inside global Inside local Outside local Outside global - - - CiscozineIf the client sends an ICMP packet or an HTTP request to the web server, the nat table will beCiscozinesh ip nat translations Pro Inside global Inside local Outside local Outside global icmp tcp - - - CiscozineRemember Because the mapped address is the same for each consecutive connection with static NAT, and a persistent translation rule exists, static NAT allows hosts on the destination network to initiate traffic to a translated host if an access list exists that allows it.Example 2 Dynamic Source NATHow to translate the network in the the ip nat insideCiscozineconfiginterface fa0/0 Ciscozineconfig-ifip nat insideDefine the ip nat outsideCiscozineconfiginterface fa0/1 Ciscozineconfig-ifip nat outsideDefine the nat pool used in the NAT translationCiscozineconfigip nat pool dynamic-ip prefix-length 29Define which network will be translatedCiscozineconfigip access-list standard client-list Ciscozineconfig-std-naclpermit the dynamic source NATCiscozineconfigip nat inside source list client-list pool dynamic-ipWith dynamic NAT, translations do not exist in the NAT table until the router receives traffic that requires ip nat translations Ciscozinebut when some packets match the ACL..Ciscozinesh ip nat translations Pro Inside global Inside local Outside local Outside global icmp tcp tcp - - - - - - CiscozineNote If a new packet arrives from yet another inside host, and it needs a NAT entry, but all the pooled IP addresses are in use, the router simply discards the can be checked enabling the “debug ip nat”.Feb 12 1926 NAT translation failed E, dropping packet s= d= user must try again until a NAT entry times out, at which point the NAT function works for the next host that sends a packet. Essentially, the inside global pool of addresses needs to be as large as the maximum number of concurrent hosts that need to use the Internet at the same time—unless we use The main difference between dynamic NAT and a range of addresses for static NAT is that static NAT allows a remote host to initiate a connection to a translated host if an access list exists that allows it, while dynamic NAT does not. You also need an equal number of mapped addresses as real addresses with static 3 Static PATHow to expose two different services on InternetThe Web server is listening on tcp port 80; this server responds on public address from the Internet outside.The SSH server is listening on tcp port 22; this server responds on public address from the Internet outside .Define the ip nat insideCiscozineconfiginterface fa0/0 Ciscozineconfig-ifip nat insideDefine the ip nat outsideCiscozineconfiginterface fa0/1 Ciscozineconfig-ifip nat outsideDefine the static PATThe web server responds on tcp port 80 on the outside’ nat inside source static tcp 80 80The SSH server responds on tcp port 666 on the outside’ interface ; in this case, the real port 22 tcp is translated to the 666 tcp port when a request comes from nat inside source static tcp 22 666Like static NAT, static PAT translation exists in the NAT translation table as soon as you configure static PAT command, and it remains in the translation table until you delete the static PAT ip nat translations Pro Inside global Inside local Outside local Outside global tcp - - tcp - - CiscozineIf an Internet client sends an HTTP request or an SSH Connection on tcp port 666, the nat table will beCiscozinesh ip nat translations Pro Inside global Inside local Outside local Outside global tcp tcp - - tcp tcp - - CiscozineExample 4 PAT – NAT OverloadHow to share an Internet the ip nat insideCiscozineconfiginterface fa0/0 Ciscozineconfig-ifip nat insideDefine the ip nat outsideCiscozineconfiginterface fa0/1 Ciscozineconfig-ifip nat outsideDefine which network will be translatedCiscozineconfigip access-list standard client-list Ciscozineconfig-std-naclpermit the NAT OverloadCiscozineconfigip nat inside source list client-list interface fastethernet0/1 overloadLike dynamic NAT, translations do not exist in the NAT table until the router receives traffic that requires translationCiscozinesh ip nat translations Ciscozinebut when some packets match the ACL..Ciscozineshow ip nat translations Pro Inside global Inside local Outside local Outside global tcp tcp tcp tcp udp udp CiscozineAre there other types of NAT/PAT?The answer is YES! One type of NAT/PAT widely used is the ip nat outside source; this command permits to translate the source address of a packet that enter in the outside’ interface and leave the inside’ simple terms, if you see the first example 1The commandip nat outside source static the to the , so the client must call the ip address to contact the server web and not the particolar type of nat is the ip nat inside destination used when multiple inside devices are identical servers with mirrored content, which from the outside appear to be a single server load define a pool of addresses containing the real hosts’ addresses ending with “type rotary” making the servers available in round-robin fashion. The access list now permits the IP address of the virtual host, what the outside world thinks is the host address. So the virtual host is with the real hosts being through configurationinterface FastEthernet0/0 ip address ip nat inside ! interface FastEthernet0/1 ip address ip nat outside ! ip nat pool real-ip-server prefix-length 24 type rotary ip nat inside destination list 1 pool real-ip-server ! ip route FastEthernet0/1 ! access-list 1 permit translation is not bi-directional in nature. You will have to use a one to one static NAT to accomplish it. A “ip nat inside source static” kind of funtionality can be achieved with the above configuration using a single address in the NAT pool, but that would only work for outside to inside apply nat inside/outside?Typically “ip nat inside” is configured on the interfaces in your local environment which cannot be routed to the Internet typically private range of IP Addresses and and “ip nat outside” on the interface which is connected to the does the router perform NAT?Inside to OutsideIf IPSec then check input access listdecryption – for CET Cisco Encryption Technology or IPSeccheck input access listcheck input rate limitsinput accountingredirect to web cachepolicy routingroutingNAT inside to outside local to global translationcrypto check map and mark for encryptioncheck output access listinspect Context-based Access Control CBACTCP interceptencryptionQueueingOutside to InsideIf IPSec then check input access listdecryption – for CET or IPSeccheck input access listcheck input rate limitsinput accountingredirect to web cacheNAT outside to inside global to local translationpolicy routingroutingcrypto check map and mark for encryptioncheck output access listinspect CBACTCP interceptencryptionQueueingSome useful comandsTo see some statistics about NAT show ip nat statisticsTo see a complete list of the static/dynamic NAT/PAT entries show ip nat translations To clear dynamic nat entry clear ip na translation *To debug NAT debug ip natReferences Configurationd'une route statique. Dans la commande suivante, le réseau à atteindre est le réseau /24 et l'interface utilisée pour joindre le réseau est ethernet 1/0. On peut aussi utiliser l'adresse IP du prochain routeur. R4 (config)#ip route 192.168.2.0 255.255.255.0 ethernet 1/0. R4 (config)#. Autre possibilité: Catégorie Travaux pratique >> TP réseaux Dernière mise à jour 09/08/2010 1451 Ajouté par Mr Mohamed Oweiss HARIGA - Contacter Lectures 25828 Commentaires 0 [ Poster un commentaire ] Note Objectif Configurer une translation d'adresse sur un routeur Cisco.. Le NAT vous permet d’utiliser des adresses IP privées sur votre LAN et de translater ces adresses afin de les rendre accessible depuis un réseau public comme Internet. Le réseau privé est définit sur l’interface intérieure et l’adresse publique sur l'interface extérieure de votre routeur. le NAT statique est une adresse privée unique qui est redirigée, vers une adresse publique unique. La forme la plus utilisée de Nat est un groupe d'adresse privées translaté en une seule et unique adresse publique. Cette forme de Nat est appelée "overloading". Configuration du nat sur un routeur cisco Lectures recommandées sur ce thème Commentaires Aucun commentaire dans la base de données *Poster un commentaire Uniquement les membres peuvent poster des commentaires Haut de page © 2022 Technologue pro, cours électricité électronique informatique © 2007 - 2022 Technologue pro - Ressources pédagogiques pour l'enseignement technologique en Tunisie Usage dans un cadre strictement académiqueTravaux pratique, pour les amateurs et pro de l'informatique, offre de TP réseaux et cours en ligne gratuit Analyse de protocoles, Câblage en Fibre optique, configuration d'un switch, routeur, Agent SNMP, access lists ACLs réseau WiFi modem ADSL .configuration nat et pat cisco pdf
