Difference between revisions of "NAT Cisco IOS"

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m (Example of static NAT)
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In static NAT The Internal IP address is always translated to the same External IP address, on a one-to-one basis.<br/>
 
In static NAT The Internal IP address is always translated to the same External IP address, on a one-to-one basis.<br/>
 
==== Example of static NAT ====
 
==== Example of static NAT ====
In teh example below, a company has acquired an Internet connection with four additional addresses.
+
In the example below, a company has acquired an Internet connection with four additional addresses 195.181.54.0/29.
 
*Connection Link address to internet 83.90.42.0/30
 
*Connection Link address to internet 83.90.42.0/30
 
**ISP uses 83.90.42.2/30
 
**ISP uses 83.90.42.2/30
 
**Company Router 83.90.42.1/30
 
**Company Router 83.90.42.1/30
 
*The network 195.181.54.0/29 is routed to 83.90.42.1 by the ISP
 
*The network 195.181.54.0/29 is routed to 83.90.42.1 by the ISP
**195.181.54.1/29 is a real IP address the company wants to use to their WEB-server
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*195.181.54.1/29 is a real IP address the company wants to use to their WEB-server
***The companys WEB-server is located on the internal private network on local IP Address 192.168.22.110
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**The companys WEB-server is located on the internal private network on local IP Address 192.168.22.110
**195.181.54.2/29 is a real IP address the company wants to use to their MAIL-server
+
*195.181.54.2/29 is a real IP address the company wants to use to their MAIL-server
***The companys MAIL-server is located on the internal private network on local IP Address 192.168.22.111
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**The companys MAIL-server is located on the internal private network on local IP Address 192.168.22.111
  
 
[[Image:Nat_static_cisco.png|none|400px|thumb|Cisco Static NAT example]]
 
[[Image:Nat_static_cisco.png|none|400px|thumb|Cisco Static NAT example]]

Revision as of 09:00, 7 March 2009

Network Address Translantion

For an explanation of NAT see Wikipedias Network address translation

Cisco NAT

Static NAT

In static NAT The Internal IP address is always translated to the same External IP address, on a one-to-one basis.

Example of static NAT

In the example below, a company has acquired an Internet connection with four additional addresses 195.181.54.0/29.

  • Connection Link address to internet 83.90.42.0/30
    • ISP uses 83.90.42.2/30
    • Company Router 83.90.42.1/30
  • The network 195.181.54.0/29 is routed to 83.90.42.1 by the ISP
  • 195.181.54.1/29 is a real IP address the company wants to use to their WEB-server
    • The companys WEB-server is located on the internal private network on local IP Address 192.168.22.110
  • 195.181.54.2/29 is a real IP address the company wants to use to their MAIL-server
    • The companys MAIL-server is located on the internal private network on local IP Address 192.168.22.111
Cisco Static NAT example
ip nat inside source static 192.168.22.110 195.181.54.1
ip nat inside source static 192.168.22.111 195.181.54.2
!
interface fastethernet 0/0
 description Connected to ISP (Outside)
 ip address 83.90.42.1 255.255.255.252
 ip nat outside
!
interface fastethernet 0/1
 description Local private LAN (Inside)
 ip address 192.168.22.1 255.255.255.0
 ip nat inside

Dynamic NAT

Overloading (Most used)

Overlapping