NAT/PAT sessions

[omendieta77]

Hi,

I'm designing a network for ISP, and I would like to know if a 7600 or 12000 router can handle NAT/PAT for 50000 clients. The thing is that we want to save public IP addresses, so we assign private addresses to the residential routers, and we will translate them in the Internet Gateway. I would like to know if one of those routers can handle such traffic and NAT/PAT sessions.

[paolo bevilacqua]

Hi, actually you did not mentioned the speed of the link to the internet. That is the most important factor in choosing a router.

Consider each NAT entry is about 312 bytes, so for example with 1 GB or RAM you can support like 3 millions of simultaneous translations. See:

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_q_and_a_item09186a00800e523b.shtml

Note: currently broadband users take in serious consideration the availability of public Vs private addresses when choosing a broadband service, so do not rule out that you will need to handle public addresses at least as a premium service.

Please rate post if it helps!

[is66rlhntadm]

Ya if your building an ISP I would highly recommend getting more real IP's as (at least here) you'd lose alot of customers that want real (aka public) IPs

[aamestica]

Hi, i work in a Celular company from Chile, and i have a problem with a NAT/PAT, realy the problem is not with a NAT/PAT, the problem is when 10000 user consulting some webpage like www.google.cl; when this happens www.google.cl take this consulting how a attack, beacause 10000 user consulting the same webpage with the same IP address. This problem you will have too, how resolve this?.

I have a 128 real IP, but the NAT/PAT complete the 65000 port the first IP en then follow with the second IP.

Thanks,

Atte

Andrés Améstica U

CCNA