NAT overload pool size

[KENT EITZMANN]

This question involves a basic NAT overload setup using a 6500/Sup720 with native IOS. The plan is to have student

wireless traffic (using private IP's) PAT'd to public IP(s) as it is routed to the Internet.

Since I don't have any large scale NAT experience I have a question ...

- If I have 500-1000+ concurrent web users, will one overload IP be enough ? If not, any real world experiences

on how big my overload pool should be ?

Thanks

[Simon Darlington]

I just came across this yesterday in my CCIE written studies.

Each inside global IP can support 65,000 concurrent tcp and udp flows (source Odom CCIE Written Exam Cert Guide)

HTH

[lee.reade]

Hi,

Just to add, PAT is Port Address Translation, so your limiting factor would be how many ports can tcp/udp support and that is 65535.

HTH

LR

[lamav]

The 65,000 number is true, in theory, but in reality, engineers who have actually tested this in a controlled environment estimate that the real number is about 4,000 -- and even then it depends on CPU strength, memory availability and allocation, and probably a few other factors.

HTH

Victor