Managed cisco catalyst switch

[hackedoff]

hi

i have a couple of Cisco Catalyst 2950 series managed switches at work.
we fitted a couple of 8 port serial device managers which plug straight into the switches. the problem we have is that the switch is seeing the 8 different ports with 8 different IP address, when in fact they need to be seen as 1 IP.

i know that if we had an unmanaged switch or hub this wouldnt be a problem and that it IS possible to change a setting or sumthing on the managed switch to resolve the issue. thing is nobody can work out/remember what to do!!!

anyone had this before and any ideas? gonna dig out the guide tomorrow, but not sure what im quite looking for yet!!

thanks