This section describes how the GRM server uses GRM domain information. It also provides information to help you decide whether specifying optional filtering criteria would be beneficial for your organization.
Note
Network Appliance recommends that you do not use domain filtering unless you must handle circumstances such as those listed in When you might want to set domain filters.
One step in configuring a GRM server is to identify GRM domains. GRM domains are fully qualified domain names (FQDNs) or DNS domains for which the GRM server is directing content requests. For a GRM DNS server, these FQDNs and domains are a subset of the authoritative domains maintained by the DNS server that can rewrite the host name. For a GRM L7 server, these FQDNs and domains are the CDN domains for which you want the server to redirect requests.
For each GRM domain that you identify, you can include optional filtering criteria to constrain the IP addresses that the GRM server will return to a client. The GRM server considers the GRM domain filtering criteria when determining which center and edge caches are eligible to handle the content request.
One GRM server can control multiple CDNs if that server is authoritative for all the domains associated with the CDNs.
Optionally, you can set the following types of policies associated with GRM domains to constrain the IP addresses that the GRM server returns:
Domain filtering is needed only if it is necessary to limit the content served by a particular group or from a particular location. See When you might want to set domain filters.
By specifying FQDNs for specific hosts within domains that the GRM server handles, you can set up the GRM server to evaluate policies that are set at the host level before evaluating the policies that are set at the GRM domain level.
Setting domain filters is optional. You can set GRM domain filters for the following:
You can set up protocol filtering for your domains for one or more of the following protocols:
You can use the following location filters, by themselves or in combination, to set up filtering on location:
Protocol, location, and group filters work together, as described in the following examples:
You might want to set domain filtering criteria in the circumstances discussed in the following paragraphs.
Assume that an edge group in the domain includes some edge caches that provide service only for streaming protocols (RTSP and MMS) and other edge caches that provide service only for HTTP.
If no protocol filtering is set then
Creating one GRM domain that filters on streaming protocols and another GRM domain that filters on Web protocols would ensure that only the IP addresses of caches that can handle the requested protocol would be returned.
If you need to restrict the locations to which content requests can be sent, for example, because of service agreements or political issues, you could create a GRM domain with filtering criteria on location. Then, when the GRM DNS server receives a DNS query for that domain, it returns only the IP addresses of caches that match the filtering criteria that you set up. Similarly, when the GRM L7 server receives a client request for the domain, it returns only IP addresses of caches that match the filtering criteria you set up.
When you set your domain filter, if you need to restrict the data centers or edge groups to which content requests can be sent, you can identify the center groups, edge groups, or both to which the requests can be sent.
The following table shows examples of filters set in the GRM domain configuration and whether the filters match characteristics identified for a particular center or edge cache.
Note
For center and edge caches, NetCache automatically determines the protocols that the cache handles. You do not have to enter protocol information when you define your center and edge caches in the GRM server configuration.
Copyright © 1994-2002, Network Appliance, Inc. All rights
reserved.
Part No. 210-00374
File: grmcom11.htm
Last updated: 11/12/02 17:45:08