[Need- Help] (NAT at Home) vs (NAT in Business) ?

[pvanvu]

HI eveyone ,
I just realized that when I use Internet at home , and the (Modem,AP,Router) was provided by ISP , I don't need to config NAT , or anything else , just plug in the cable , or use wireless to access to the Internet . SO I have a few questions still confusing :

1) Is NAT already pre-configured on home (Modem , AP ,Roter) ?

2) Even in school , when I practiced on Cisco devices , Just using E-cable to connect the Internet without configuring NAT
-> Is NAT already pre-configured on school Routers ?

3) I learned about Cisco network , but I have never met any situation about configuring NAT on a real Network ( I think they were already pre-configured before ) , so I don't have any experience about this , so my questions :
-> In what case should we configure a NAT on a Network ?
( from a Brand new Network ? )
( Or to Public Server only ? )
( Or only used in Big Business with huge Network ? ) ,

4) no need to config NAT on home Network , or small Business Network , because the Router provided by ISP is already pre-configured ?


Thanks

 

[MtnMan]

You have a very limited understanding of NAT (maybe), but you questions lead me to believe you really don't know how it works, or you could answer your own questions.

 

[Gryz]

HI eveyone ,
I just realized that when I use Internet at home , and the (Modem,AP,Router) was provided by ISP , I don't need to config NAT , or anything else , just plug in the cable , or use wireless to access to the Internet .

You do realize that there is not one type of NAT ? There are a dozen or so. The type of NAT most of us use at home is one of the simplest forms of NAT.

1) Is NAT already pre-configured on home (Modem , AP ,Roter) ?

It is the router that does NAT. Not an (internal or external modem). Not the WiFi attach-point.

Your router is partially pre-configured, and partially does auto-configuration.
NAT is enabled by default. (Which is imo something different from pre-configured). And some assumptions are made. E.g. your DSL or cable interface are the "outside interface" and your ethernet and WiFi are the "inside interface". By default there is a private address range (rfc1918) configured on your internal interface. And your external interface does DHCP to get its IP address, or uses PPP to get its IP address. The NAT these routers use is 1-to-many, also called PAT of NATP. Your router is a DHCP server on the inside network. Etc, etc. With these settings, your router becomes plug-and-play without additional configuration required.

2) Even in school , when I practiced on Cisco devices , Just using E-cable to connect the Internet without configuring NAT
-> Is NAT already pre-configured on school Routers ?

A "school router" is not a technical term.
No idea what you mean, and no idea how those routers at your school are configured.
Most likely the admin(s) of your school have done some extra configuration on them. Depends on the size of your school, and what your school wants to support. E.g. if you have a 1000 people accessing the Internet at rougly the same time, 1 public IP address (with 65k portnumbers) is not enough. Then you need few-to-many NAT, not 1-to-many NAT.

3) I learned about Cisco network , but I have never met any situation about configuring NAT on a real Network ( I think they were already pre-configured before ) , so I don't have any experience about this , so my questions :
-> In what case should we configure a NAT on a Network ?
( from a Brand new Network ? )
( Or to Public Server only ? )
( Or only used in Big Business with huge Network ? )

Read this:
https://en.wikipedia.org/wiki/Network_address_translation
https://en.wikipedia.org/wiki/Carrier-grade_NAT
https://en.wikipedia.org/wiki/NAT64

Basically whenever you have a situatiion where you do something more complex, or on a bigger scale, then a one-family-at-home situation, your probably need to configure NAT. This means schools, medium and large businesses, ISPs, etc.

4) no need to config NAT on home Network , or small Business Network , because the Router provided by ISP is already pre-configured ?

Small home-routers do some auto-configuration. And the default values of configuration are already so that your router becomes plug-and-play. Your ISP does very little extra configuration (what I would call pre-configuration).

 

[JackMDS]

The nature of the use is so that the default config. of Entry level Router.NAT fits most of Entry level users/Home/SOHO/Small Buisness

Big business with few Networks and other special Global demands needs more configuration but otherwise NAT is NAT.

What one have to concentrate on is the nature and demands of his/her system, then choose the right hardware and not vise versa.

The confusion around all Internet/Network issues comes from ignorance and false marketing.

Users do not get it that Combo Wireless Modem/Router is a Plastic Box that includes Modem, Routing circuits/NAT, Wired switch, and Access Point (Wireless switch). While the three are in same box and connect one to the other each one is an Independent Entity that has its own function.



😎

 

[pvanvu]

You do realize that there is not one type of NAT ? There are a dozen or so. The type of NAT most of us use at home is one of the simplest forms of NAT.

It is the router that does NAT. Not an (internal or external modem). Not the WiFi attach-point.

Your router is partially pre-configured, and partially does auto-configuration.
NAT is enabled by default. (Which is imo something different from pre-configured). And some assumptions are made. E.g. your DSL or cable interface are the "outside interface" and your ethernet and WiFi are the "inside interface". By default there is a private address range (rfc1918) configured on your internal interface. And your external interface does DHCP to get its IP address, or uses PPP to get its IP address. The NAT these routers use is 1-to-many, also called PAT of NATP. Your router is a DHCP server on the inside network. Etc, etc. With these settings, your router becomes plug-and-play without additional configuration required.

A "school router" is not a technical term.
No idea what you mean, and no idea how those routers at your school are configured.
Most likely the admin(s) of your school have done some extra configuration on them. Depends on the size of your school, and what your school wants to support. E.g. if you have a 1000 people accessing the Internet at rougly the same time, 1 public IP address (with 65k portnumbers) is not enough. Then you need few-to-many NAT, not 1-to-many NAT.

Read this:
https://en.wikipedia.org/wiki/Network_address_translation
https://en.wikipedia.org/wiki/Carrier-grade_NAT
https://en.wikipedia.org/wiki/NAT64

Basically whenever you have a situatiion where you do something more complex, or on a bigger scale, then a one-family-at-home situation, your probably need to configure NAT. This means schools, medium and large businesses, ISPs, etc.

Small home-routers do some auto-configuration. And the default values of configuration are already so that your router becomes plug-and-play. Your ISP does very little extra configuration (what I would call pre-configuration).

Thank Gryz a lot , I got it now
BTW , you are always my Hero , my Savior ()🙂
:thumbsup::thumbsup::thumbsup:

The nature of the use is so that the default config. of Entry level Router.NAT fits most of Entry level users/Home/SOHO/Small Buisness

Big business with few Networks and other special Global demands needs more configuration but otherwise NAT is NAT.

What one have to concentrate on is the nature and demands of his/her system, then choose the right hardware and not vise versa.

The confusion around all Internet/Network issues comes from ignorance and false marketing.

Users do not get it that Combo Wireless Modem/Router is a Plastic Box that includes Modem, Routing circuits/NAT, Wired switch, and Access Point (Wireless switch). While the three are in same box and connect one to the other each one is an Independent Entity that has its own function.



😎

Thank JackMDS a lot
I got it now :thumbsup::thumbsup::thumbsup:
()🙂