Hi,
NAT Feature Support on Catalyst Switches:
Catalyst 6500/6000?CatOS1 with Cisco IOS? Software on MSFC2/MSFC2/MSFC3
All versions
Catalyst 6000?CatOS (MSM3)
No support
Catalyst 6500/6000?Cisco IOS system software
All versions
Catalyst 5500/5000 (RSM) 4
Cisco IOS Software Releases 11.2(P),11.3(T), 12.0, 12.0T, 12.1, 12.1T
Catalyst 5500/5000 (RSFC5)
Cisco IOS Software Release 12.1
Catalyst 4500/4000?CatOS (WS-X4232-L3)
No support/no plans
Catalyst 4500/4000?Cisco IOS Software (Supervisor Engine II+/III/IV/V)
No support currently6
Configuring NAT:
http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a008044eddc.html
BR,
Bjornarsb