@eunicemeukieje, Greetings,   Actually, I faced such a problem, and I have searched everywhere! but I wasn't lucky enough to find such an issue solved anywhere, I have found some suggestion from a Cisco Employee through "Cisco Learning Network" website, and he was suggesting Replacing  the switch! as a result, the one who issued that problem replaced it!!!!!!! I couldn't believe that it can happen!    Anyway, and without any more prolongation, I have fixed it, and I would like to share my experience in order to point others to the hardware limitations as well!    The Solution was simply to open the body of the switch itself, and to plug out the console port wire from the switch board, then power the switch on, and again turn it of, and finally plug in the console wire back, when you power the switch, the console input will work prefect!    Note: you can check the disassembly process and procedures photos as attached!    The conclusion, is some time you need to assume some hardware limitations when you pass all the usual software troubleshooting procedures!    Thanks, and wishing to be useful and helpful for those who suffer the same issue, or even to be added as an additional experience to the people who like to learn!    Please don't forget to rate all helpful responses and mark solutions!  It will be so nice from you! Bst Rgds, Andrew Khalil ... View more

@ciscogeek2017 Greetings,  In addition to the reply of @balaji.bandi i would like to add that In you case you should use the off mode, and as a result you will not find any traffic related to the vtp in your network.   Please don’t forget to rate all helpful responses and mark solutions!  Bst Rgds, Andrew Khalil   ... View more

@102, Greetings,   To redirect web traffic to a different port, issue the  ip nat inside source  { static {tcp   local-ip local-port global-ip global-port   } [extendable]  command or the  ip nat outside source  { static tcp  global-ip global-port local-ip local-port} [ extendable ] command in global configuration mode, depending on whether a web server is available on the inside or outside network. This command creates a permanent extended translation entry in the NAT table, which includes the protocol and port information. To define the NAT inside and outside interfaces, issue the   ip nat   inside   command and the   ip nat outsidecommand under the interfaces.   For example, a web server with address 192.168.1.1, available on the inside network, is configured to listen on Transmission Control Protocol (TCP) port 8080. The users belonging to the inside network access this server using the configured port number. The same web server is accessed from the outside network using the same IP address, but the standard TCP port is 80. This output shows how the relevant configuration on the NAT router appears:   interface Ethernet0 ip address 192.168.1.100 255.255.255.0 ip nat inside !--- Designated as the NAT inside interface. interface Serial0 ip address 10.1.1.1 255.255.255.0 ip nat outside !--- Designated as the NAT outside interface. ip nat inside source static tcp 192.168.1.1 8080 192.168.1.1 80 extendable !--- The above line configures a static NAT mapping for the web server 192.168.1.1, which is available on the inside network.   This command translates the TCP source port number 8080 to 80 for all traffic going from the inside to the outside network. In turn, this configuration translates the destination port number from TCP 80 to 8080 for traffic going from the outside to the inside network.   Please don't forget to rate helpful responses and mark solutions! Bst Rgds, Andrew Khalil ... View more

@networkchef, Greetings, I would prefer that you check this link: https://community.cisco.com/t5/networking-documents/reading-and-understanding-the-ospf-database/ta-p/3145995   It should answer all your questions deeply!   Please don't forget to rate all helpful responses and mark solutions! Bst Rgds, Andrew Khalil ... View more

@networkchef Happy to help dear!  Please don't forget to mark solutions!  Bst Rgds, Andrew Khalil ... View more

@giangle please share us all the configuration of both switches, otherwise it so difficult to troubleshoot!   Please don't forget to rate all helpful responses and mark solutions! Bst Rgds, Andrew Khalil ... View more

@networkchef, Greetings, They are not related ))) and it's not what I meant!   but let me explain it in a chronological sequence! Let's imagine that we are creating (just now) a lab contains 3 routers and 1 switch, when we connect the 3 routers (int g0/0) to the switch (int f0/1, f0/2, f0/3), there is nothing in the mac-address table of the switch, as by default the routers interfaces are still down and none of the routers sent anything to the switch yet! Once you issue #no shutdown, for the int g0/0 of R1, R2 and R3, and then go to the switch and issue #show mac address-table, you shouldn't find any mac addresses!  Once you ping from R1 which for example has the IP add 10.1.1.1 to the IP 10.1.1.2 (this IP address is given to R2 and R3) so, the router send ARP packet to resolve the mac add of the device that has this IP (at this moment the mac address of R1 is recorded in the mac address table of the switch corresponding to the int f0/1 ) and the switch floods this messages to all its ports, the one who answers first, will be considered the active one (and usually f0/2 will answers before f0/3 because it gets the packets first). That's why R2 will reply for the ICMP while R3 not! The most interesting that if you shutdown R2, and ping again from R1, R3 will not reply, as R1 knows the mac address that represent the IP address 10.1.1.2, to make it replying, you can ping 10.1.1.1 from R3, by this way R1 will learn that the mac address of R3 is representing 10.1.1.2 and next time you ping from R1, R3 will reply!   I hope it's clear, you can test it using real devices or packet tracer, I prefer packet tracer to see the packets during the process and to filter what packets you would like to monitor!    Please don't forget to RATE any helpful responses and MARK solutions! Bst Rgds, Andrew Khalil    ... View more

@networkchef, Greetings, Actually it depends, if R3 sends traffic first so the ping from R1 to 12.0.0.2 will go to R3 not R2. But if it didn't send traffic never while R2 is connected to a lower interface id (like f0/2 is lower than f0/3) so it will reply for the ARP first and then the ping goes to the R2 all time instead of R3.   Please don't forget to rate helpful responses and mark solutions! Bst Rgds, Andrew Khalil ... View more