3Com OfficeConnect 3CP4144 Cli User's Manual

Also see for OfficeConnect 3CP4144: Get started guide Release note Technical support How to set up

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6-10 C HAPTER 6: M ANUAL SETUPStatic NAT port mappings or the NAT default address need to be configured whenan application will initiate a TCP or UDP connection from the public network. If apublic accessible Server resides on a privately addressed LAN, static ports can bedefined for the applications they are running. For example, TCP port 80 for a WebServer and TCP port 21 for an FTP server can be statically assigned. The NATdefault address can be used with or instead of static port assignments, and is setto the private address of a workstation on the local LAN. If an incoming IP datapacket is received on a WAN port and there is no existing dynamic or static portmapping, the packet will be translated using the NAT default address.Configuring NAT Typically, NAT only needs to be enabled or disabled for a remote site connection.n Use the following command to configure NAT in a VC profile:set vc nat enableAs stated in the above overview, it is sometime necessary to configure theWorkstation default address. This field should be set to the private address of aworkstation on the local LAN. If a data packet is received on the WAN port and aport mapping does not exist, the frame will be translated using the Workstationdefault address.n Use the following command to set this field:set vc nat_default_address Static port configurations map a public port to a private IP address/port. Both TCPand UDP static ports can be defined. Remote sites can have multiple static portsdefined. If static ports and the Workstation Default Address are defined, the staticports take precedence.n Static ports are defined for TCP and UDP ports with the following commands:add nat tcp vc public_port private_address private_port add nat udp vc public_port private_address private_port Note: Typically the private and public port numbers are configured for the samevalue (i.e. 21 for an FTP Server). However, you can map multiple public portnumbers to the same private port number. For example, if you want to support aWeb Server on the LAN and be able to manage your OfficeConnect Remote 812with the Web Browser, you would define 2 static ports for the Web Server (TCPport 80). Configure your LAN Server with public port 80, private port 80, and theprivate address of the LAN Server. Configure yourocr812 manager with public port8080, private port 80 and the private address equal to the ethernet port IPaddress. To access the ocr812 from a Web Browser, type in: public Address:8080.The value 8080 was chosen for example purposes only, you can use any valuewithin the port number range (i.e. 81).