704 CHAPTER 17: USING 3COM NETWORK DIRECTOR ON A MULTI-S ITE NETWORKIssues and Techniques when Configuring the Retry/TimeoutHierarchyWhen configuring the Retry/Timeout hierarchy in a multi-site networkthere are various issues to look out for, and techniques that may beemployed to address them:■ Before starting to configure the retry/timeout hierarchy, it is importantto correctly identify the local and remote sites with regards to the PCthat 3Com Network Director is running on. Where possible, each siteshould be identified by the IP subnets that are unique to that site.■ If your network is configured such that the IP addresses within asubnet are allocated to different sites and the numbers of retries andtimeout periods that you have determined for these sites differ thenyou will be unable to override the whole map settings at the subnetlevel such that you satisfy the requirements of the different sites. Forexample, you may have allocated an IP range from within a particularsubnet for use by dial-in users, while the remainder of the subnet is inuse by the local site.■ In order to cope with this situation you will need to first determineone site to treat as the home of the subnet. In the example givenabove, this would likely be the local site. The numbers of retries andtimeout periods for the subnet should be configured appropriate forthe site that you select as the home of the subnet. Having done thisyou will then need to override the subnet settings for each device thatis on that subnet, but that is not located at the local site.It is only really necessary to override the subnet settings for a devicewhere the device is not located at the home site of the subnet if youintend to monitor or manage that device. In the example given aboveyou may decide that, as they will likely be user’s PCs, you will not monitoror manage any of the discovered dial-in devices on the subnet, in whichcase it would not be necessary to override the subnet settings for thosedevices.Routers and layer-3 switches inherit their settings from the whole mapsettings, not from the subnets that they are members of. As a result, inorder to configure the correct settings for all devices at a site you willneed to apply the settings not only to each subnet that covers that site,but also to each router and layer-3 switch that is located at that site.If you have determined that the appropriate numbers of retries andtimeout periods for a large number of remote sites are identical then it
