Security 7-19to go through many checkpoints.n Too much reliance on packet filters can cause too little relianceon other security methods. Filter sets arenot a substitute forpassword protection, effective safeguarding of passwords, callerID, the “must match” option in the answer profile, PAP or CHAP inconnection profiles, callback, and general awareness of how yournetwork may be vulnerable.An approach to using filtersThe ultimate goal of network security is to prevent unauthorizedaccess to the network without compromising authorized access. Usingfilter sets is part of reaching that goal.Each filter set you design will be based on one of the followingapproaches:n That which is not expressly prohibited is permitted.n That which is not expressly permitted is prohibited.It is strongly recommended that you take the latter, and safer,approach to all of your filter set designs.Working with IP filters and filter setsThis section covers IP filters and filter sets. For working with IPX filtersand filter sets, see “IPX filters,” beginning on page 5-11.To work with filters and filter sets, begin by accessing the filter setscreens.Note: Make sure you understand how filters work before attemptingto use them. Read the section “About filters and filter sets,” beginningon page 7-9.MainMenuAdvancedConfig.FilterSets IP
