Catalyst 6009 switch - NAT

[scrimmy]

We use a Cisco Catalyst 6009 switch to run our network divided into 10 VLANS and are planning to replace some of our servers - about 20 servers in all.
Each server has up to 500 users logged onto them using telnet sessions.
In order to make the transition appear seamless to the end users and to have a back-out plan in place, is it possible for the Catalyst to translate/redirect the original telnet target IP address to the IP address of the new server?
I think you can use NAT but I have no idea how to configure it.
If this were possible what would the effect be on the CPU’s load of the Catalyst?

WS-C6009 Software, Version NmpSW: 5.5(2)
example VLAN config:
conf t
interface vlan 8
ip address 172.30.8.250 255.255.255.0
ip directed-broadcast
no ip redirects
standby 1 priority 140 preempt
standby 1 ip 172.30.8.1
standby 2 priority 110 preempt
standby 2 ip 172.30.8.2
no shut
exit
router ospf 100
network 172.30.8.0 0.0.0.255 area 0
exit

A server with an IP address of 193.39.1.1 is to be replaced with a server with an IP address of 172.31.1.1

Many thanks for any help.

 

[wdugger]

This would not be a feature of the switch but a feature of the MSFC or MSM, depending on when you purchased the switch.

You should be able to do it with NAT but if you are using MLS it will not work. The link below should help you get started on the right road. Once you look at the link and get an idea of the concept let me know and I will help you out.

http://www.cisco.com/warp/customer/556/2.html

It might be better to use a secondary IP address's.

 

[scrimmy]

Hi, thanks for the tip, but I am still getting nowhere fast.

The old server is 172.30.50.230
The new server is 172.30.51.230
Configs are:
interface Vlan50
ip address 172.30.50.250 255.255.255.0
no ip redirects
ip directed-broadcast
ip nat inside
!
interface Vlan51
ip address 172.30.51.250 255.255.255.0
no ip redirects
ip directed-broadcast
ip nat outside

ip nat inside source static 172.30.51.230 172.30.50.230

RouterA#sh ip nat statistics
Total active translations: 1 (1 static, 0 dynamic; 0 extended)
Outside interfaces:
Vlan51
Inside interfaces:
Vlan50
Hits: 127 Misses: 0
Expired translations: 0
Dynamic mappings:

RouterA#sh ip nat translations
Pro Inside global Inside local Outside local Outside global
--- 172.30.50.230 172.30.51.230 --- ---

RouterA#traceroute 172.30.50.230

Type escape sequence to abort.
Tracing the route to 172.30.50.230

1 172.30.51.230 4 msec 4 msec 4 msec

ping and traceroute work fine, but the telnet traffic is not redirected to the new server.
I have also tried the following commands
ip nat inside source static tcp 172.30.51.230 23 172.30.50.230 23
and
ip nat inside source static tcp 172.30.51.230 1723 172.30.50.230 1723
But this makes no difference