Exam 350-401 topic 1 question 905 discussion

To allow Internet users to access the web server on HTTP port 80 when the web server is configured to listen only on TCP port 8080, you need to create a static Network Address Translation (NAT) rule that translates incoming requests on port 80 to port 8080 on the web server. The correct command to achieve this is: C. `ip nat inside static tcp 10.1.1.100 8080 172.16.1.3 80` Here's a breakdown of the command: - `ip nat inside static tcp`: This specifies a static NAT translation for TCP traffic on the inside interface. - `10.1.1.100 8080`: This is the local address of the web server and the port it's listening on (8080). - `172.16.1.3 80`: This is the public address (on the outside interface) and the port that will be used for incoming traffic (80). So, the command translates requests coming to `172.16.1.3` on port `80` to `10.1.1.100` on port `8080`, effectively allowing the web server to receive HTTP requests on port 80.

ip nat inside static tcp 10.1.1.100 8080 172.16.1.3 80

All options are wrong command syntax. ---------------------------- INET(config)#ip nat inside static tcp 10.1.1.100 8080 10.1.1.100 80 ^ % Invalid input detected at '^' marker. ---------------------------- The correct command syntax is as follows C. ip nat inside source static tcp 10.1.1.100 8080 172.16.1.3 80 Cisco exam question writers should review the questions they create.

none of this makes sense... internet users are outside using port 80... they have to be translated from OUTSIDE to and then to use port 8080.. the answer is D

C is correct since we want to allow external users to access the internal web server on port 80 while the server listens on port 8080, the inside NAT rule is appropriate.

IMHO, the only valid explanation of this mess is that while we are "outside" we still not in the "internet" which implies that internet SNAT/DNAT is happening in an other device not showing in the diagram and therefor we are using private space of 172.16... This reduce the question to tcp port redirection and, in that case answer will be C.

In the exibit 3. Redirect TCP Traffic to Another TCP Port or Address part the scenario is the same and the nat is applied to inside. There is a note under the config which goes: Note: The configuration description for the static NAT command indicates any packet received in the inside interface with a source address of 172.16.10.8:8080 is translated to 172.16.10.8:80. This also implies that any packet received on the outside interface with a destination address of 172.16.10.8:80 has the destination translated to 172.16.10.8:8080. The server is still listening and http requests are received from outside but this note is pretty explanatory. https://www.cisco.com/c/en/us/support/docs/ip/network-address-translation-nat/13772-12.html#toc-hId--521872001

D. is incorrect, I think. There is no appropriate outside static NAT option in the given answers. For the outside static NAT, the command should that; "ip nat outside static tcp 172.16.1.3 80 10.1.1.100 8080", I think.

The correct answer is "С", tested on eve-ng

D, 'ip nat outside static tcp 10.1.1.100 80 10.1.1.100 8080', This command means that TCP traffic coming from the outside network to port 80 of IP address 10.1.1.100 will be redirected to port 8080 of the same IP address.

answers doesn't make sense in my opinion

I think its D. The server only listens on 8080 while users from internet send traffic to port 80 First Command: ip nat inside static tcp 10.1.1.100 8080 10.1.1.100 80 ip nat inside: This means the translation is applied for traffic originating from the inside network (private network) going out to the outside network (public network). The translation is from port 8080 on the internal host to port 80 on the external side. Second Command: ip nat outside static tcp 10.1.1.100 80 10.1.1.100 8080 ip nat outside: This means the translation is applied for traffic originating from the outside network (public network) coming in to the inside network (private network). The translation is from port 80 on the external side to port 8080 on the internal host. I think the question is referring to the latter... let me know if the understanding is incorrect

All answers are kinda wrong as Internet users won't be able to access the internal IP without that being NATted too. But C would also allow internal users to access the server on port 80.

This command effectively maps incoming TCP traffic on port 8080 to the web server's port 80, allowing external users to access the web server on the standard HTTP port 80.