Question about networking in the real world
When routing to the internet do you configure a default route to the ISP's router or do you have create the static route and NAT it?
Comments
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networker050184
Mod Posts: 11,962 Mod
Not sure exactly what you are asking, but unless you use a dynamic protocol (usually BGP when connecting to the internet) you will need a static default route to the internet NAT or not.An expert is a man who has made all the mistakes which can be made. -
sizeon
Member Posts: 321
My question is do you need to NAT even though you have a default route to the ISP router? -
JeanM
Member Posts: 1,117
Depends on the config? But most likely your local office/branch would be behind edge/asa and then nat/pat ? Is that what you are asking?2015 goals - ccna voice / vmware vcp. -
sizeon
Member Posts: 321
But why do you need NAT when the ISP router is on premise? wouldnt you just configure a static route for the next hop ip which is the ISP router? And the ISP router will NAT for you?
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networker050184
Mod Posts: 11,962 Mod
Depends on the config. Ask the ISP.An expert is a man who has made all the mistakes which can be made.
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ccnxjr
Member Posts: 304 ■■■□□□□□□□
Depends on your setup.
Will people on the local LAN require access to anything outside?
Is your local lan using private IPs ?
If users on your local lan are using private ip addresses, and require access to the public internet , there will need to be a nat mapping the inside IP's and ports to a public IP/port on your router (or gateway or whatever device actually has a public IP)
This is a common setup.
However, if all the nodes within your network have public IP addresses, then no NAT is required.
Less common (but not unusual).
The deal with NAT/PAT is that you only have one(or just a few) publicly routable IP address and it has to serve the needs of several private IP addressed nodes.
It's generally the responsibility of the business /end user to have a NAT/PAT solution, as the ISP will just give you a public IP address and it's up to you to decide how to use it.
Thats why for small business/homes they'll also supply a router that's already configured to automatically perform NAT/PAT for any devices connected to the "LAN" ports.
If every device that requires public internet access has a publicly routable IP address , then NAT/PAT it isn't needed.
Which is one of the benefits of migrating to IPv6 , substantial amounts of publicly routeable IP addresses! -
sizeon
Member Posts: 321
Thanks, this answered my question.Depends on your setup.
Will people on the local LAN require access to anything outside?
Is your local lan using private IPs ?
If users on your local lan are using private ip addresses, and require access to the public internet , there will need to be a nat mapping the inside IP's and ports to a public IP/port on your router (or gateway or whatever device actually has a public IP)
This is a common setup.
However, if all the nodes within your network have public IP addresses, then no NAT is required.
Less common (but not unusual).
The deal with NAT/PAT is that you only have one(or just a few) publicly routable IP address and it has to serve the needs of several private IP addressed nodes.
It's generally the responsibility of the business /end user to have a NAT/PAT solution, as the ISP will just give you a public IP address and it's up to you to decide how to use it.
Thats why for small business/homes they'll also supply a router that's already configured to automatically perform NAT/PAT for any devices connected to the "LAN" ports.
If every device that requires public internet access has a publicly routable IP address , then NAT/PAT it isn't needed.
Which is one of the benefits of migrating to IPv6 , substantial amounts of publicly routeable IP addresses!
