Illegal dhcp (DHCP Snooping )

Question

hi,
in my network , where there is a dhcp (i use dhcp relay on my layer 3 switch),
often someone connect a pc with a service of dhcp service active , and this produces a problem.
i read in cisco.com and i find the documentation about how to fix this problem.
DHCP Snooping is the solution.
The release on my cisco 6509 with msfc2 not support this feature.
WHAT DO YOU THINK ABOUT IT ?
HAVE YOU A LINK WITH AN EXAMPLE OF ALTERNATIVE METHODS?
Thanks
FC

Answer 1

my version are:
IOS (tm) MSFC2 Software (C6MSFC2-JSV-M), Version 12.1(11b)E4
in CAT OS
WS-C6509 Software, Version NmpSW: 7.6(8)
Step 1. (Permit DHCP response from host 1.2.3.4). "set security acl ip SERVER permit udp host 1.2.3.4 any eq 68"
Step 2. (Deny DHCP responses from any other host). "set security acl ip SERVER deny udp any any eq 68"
Step 3. (Permit other IP traffic). "set security acl ip SERVER permit any any"
Step 4.(Commit the VACL)."commit security acl SERVER"
Step 5.(Map the VACL to VLAN 10 for example). "set security acl map SERVER 10"
WHAT DO YOU THINK ABOUT MY CONFIGURATION?
Thanks
FC