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New Member

How can my network access the Internet?

Hi all,


All in GNS3 lab scenario I created.

Hope anybody can shed light on this matter.  I have for example a multi area OSPF domain.  Like all of my remote sites are in area x, y, and z and all connects to area 0, in the area 0 I have this ASBR 7200 that has an EBGP peer to R1 (ISP) that connects to R2 and R2 connects to R3, which in turn R3 connects back to my ASBR 7200.


I would like to know how can I reach all of the BGP subnets being advertised by R1 (basically the internet) from my remote sites in area x, y and z?  As you can see in the topology I am using obviously RFC 1918 addresses on my network and I used all public IP addresses on the BGP routers.  I would like to know how I can reach all those for example all 500,000 routes in order for my remote sites to access the internet?  I can't redistribute BGP into my OSPF (since it will break).  I tried configuring the subnets on my remote sites on the ASBR 7200 using network command, and the BGP routers can see those subnets, but inside my network I cannot see the subnet that I have created in R3 (pretending it's an internet site).  What seems to be missing in my config in the ASBR?


Please any inputs gladly appreciated.


Please remove configuration in 3RD_PARTY-7200-ASBR router, I would like to know how can my local sites see loopback in R3 without redistribution into OSPF...

 redistribute bgp 65535 subnets


Is it required that all sites

Is it required that all sites have the 500,000 routes? If not how about injecting an default ospf route sending all traffic to R1?

New Member

Yes, I have done that, as not

Yes, I have done that, as not to do redistribution, thanks for that advice, but my next question is how can the RFC 1918 addresses access the ISP's or internet?  It seems I need to do NAT'ting on the RFC 1918 and point it to the f0/0 and ser3/0 interfaces since those IP addresses are seen by R1, R2 and R3.  Would that be the next course of action?

Yes you will need to NAT at

Yes you will need to NAT at some point to go from private to public address space. Here is a basic configuration if you are interested:

interface F8

ip nat inside

interface G0

ip nat outside

ip access-list standard NAT

ip nat inside source list NAT interface G0 overload

New Member

Hi, I did that, unfortunately

Hi, I did that, unfortunately NAT is not translating in my GNS3 lab topology...

Could you take a look what is missing since I can't seem to translate my local subnets in order for it to access the R1, R2, R3.  The subnet is not in the RIB of my remote sites router....NY-3640, TX-7200 or LA-3745.  I can ping the ip adress from R1, but I can't seem to ping the from NY-3640, TX-7200 or LA-3745, also the ip nat translation is not showing.


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