Scenario 1: Multiple cache administration at multiple POP sites

Implementation requirements

In this scenario, a telecommunications company, Company XYZ, uses global configuration files to administer 55 appliances installed to service Web and streaming requests at multiple POP sites over a geographic area that spans multiple time zones.

Advantages of multiple-cache configuration

The primary reasons for implementing multiple-cache management at Company XYZ are

To minimize the task of administering individual appliances locality
To avoid conflicting configuration settings among multiple appliances
To simplify the task of appliance vendor support

The configurations for all appliances run by Company XYZ are stored and accessible at a single location.

Multiple cache architecture

The multiple-cache configuration of Company XYZ is designed to minimize the number of settings that are made to each appliance's local.cfg file.

Running configuration versus local configuration

appliances always store the running configuration and, after a reboot, load the last running configuration, rather just using the settings specified in the local.cfg file.

Therefore, a configuration scheme that specifies the default gateway, DNS server, and time-zone configuration in a global configuration file rather than the in local.cfg file presents no problem even though default gateway, DNS server, and time-zone configuration are necessary to local appliance reboot operations.

Global configuration file types

At the central administration site, the administrator creates and maintains the global configuration files shown in the following table on a centralized FTP server.

Sample global configuration file	Contents
common.cfg	Settings common to all appliances.
pop_name.cfg	Settings specific to each POP (one file for each POP site).
http.cfg	Settings to configure HTTP. This file is used by most appliances in the company.
streaming.cfg	Settings to configure RTSP- and MMS- based streaming. Only select appliances at each POP use this file.

Global configuration file assignment

One of the Company XYZ appliances at the POP BBB has the following config.admin.config.list option setting entered into its local.cfg file:

config.admin.config.list = \\

default.cfg

ftp://30.30.30.30//nc/5.0.1/common.cfg

ftp://30.30.30.30//nc/5.0.1/pop_bbb.cfg

ftp://30.30.30.30//nc/5.0.1/http.cfg

ftp://30.30.30.30//nc/5.0.1/streaming.cfg

local.cfg

\\

Contents of the common.cfg file

The common.cfg file contains settings common to all appliances at Company XYZ. Comment lines are prepended by #.

#!Config V5.300

# Allow scrolling after pressing <RETURN>

config.cli.show_chunk = 15

# IP Forwarding for troublesome sites

config.transparency.bypass_ip.addrs = \\

1.1.1.1

2.2.2.2

3.3.3.3

4.4.4.4

5.5.5.5

\\

config.transparency.bypass_ip.enable = on

# SNMP

config.snmp.auth_traps.hosts = \\

200.1.1.1

204.2.2.2

\\

config.snmp.enable = on

# Autosupport

config.autosupport.from = netcache@someone.net.mx

config.autosupport.recipients.note = \\

netcache@someone.net.mx

autosupport@netapp.com

\\

config.autosupport.recipients.full = \\

autosupport@netapp.com

netcache@someone.net.mx

\\

config.autosupport.mailhosts = 1.2.3.4

config.autosupport.enable = on

# Messages Log File

config.system.logs.period = 360

config.system.logs.trigger = size

config.system.logs.max_size = 1999

config.system.logs.technique = rotate

# Time Server

config.system.timed.servers = 2.3.4.5

config.system.timed.proto = rdate

config.system.timed.max_skew = 1h

config.system.timed.enable = on

# DNS

config.system.dns.domain_tree_search_enable = off

config.system.dns.domainname = someone.net.mx

# AdminList Refresh Activity

# Refresh every day at midnight

config.admin.config.refresh.sched_type = daily

config.admin.config.refresh.schedule = 0

config.admin.config.refresh.trigger = scheduled

# Avoid to CONNECT through appliances on

Port 25

!25

\\

# Change GUI password to <something>

config.auth.users = admin:!@#$%^&*()

Configuration refresh settings

To more easily control the time of configuration refreshes, the administrator moves the configuration refresh schedule settings to the common.cfg file.

Contents of the POPname.cfg file

Each POP-specific configuration file at Company XYZ contains the following information:

WCCP router list
Default gateway
DNS name servers
Time zone

#!Config V5.300

config.wccp.routers = \\

10.1.1.1

20.2.2.2

\\

config.system.timezone = America/Mexico_City

config.system.gateways.ip = 10.1.1.2.2

config.system.dns.nameservers = \\

10.11.11.11

10.12.12.12

10.13.13.13

\\

#

#config.transparency.bypass_ip.addrs += \\

#10.11.12.13

#\\

WCCP router configuration

WCCP routers are specified in the POP-specific configuration files. Because the POP-specific files are listed after the common file, the WCCP features are not enabled in the common file.

Note
If you want to enable DNS caching service on the appliance, a better strategy might be to list the POP-specific configuration file first, or to provide a pre and post version. By providing a pre and post version, you can specify WCCP routers early in the pre file and then specify local "additions" to common configurations in the post file.

Contents of the http.cfg file

The http.cfg file contains settings specific to Company XYZ's Web appliances.

#!Config V5.300

config.http.ports = 80

config.http.transparency = on

config.wccp.http.enable = on

config.http.default_max_age = 2592000

config.http.req_lastmod = on

config.http.logs.access.format = \\

x-localtime time-taken c-ip x-transaction bytes cs-method cs-uri x-
username x-hiercode rs(Content-Type) x-note

\\

Contents of the streaming.cfg file

The streaming.cfg file contains settings specific to Company XYZ's streaming appliances.

#!Config V5.300

config.rtsp.transparency = on

config.rtsp.enable = on

config.mms.transparency = on

config.mms.enable = on

config.wccp.rtsp.service_number_udp = 5

config.wccp.rtsp.service_number_tcp = 4

config.wccp.rtsp.enable = on

config.wccp.mms.service_number_udp = 3

config.wccp.mms.service_number_tcp = 2

config.wccp.mms.enable = on

Cache installation procedure

The administrators install each new appliance at Company XYZ with the following steps:

Physically install each appliance on its rack.
Boot the appliance.
Carry out the setup and installation procedures, which include installing license codes.
Clear most local configuration settings on each appliance with the CLI config -z command.
Set the global configuration file sources for each appliance using the set config.admin.config.list command and option at the CLI console for that appliance.
Clear the default gateway and DNS name server settings from the local.cfg file of each appliance by using the following clear commands in the CLI console for that appliance:
```
clear config.system.gateways.ip
```
```
clear config.system.dns.nameservers 
```

Multiple-cache change control

To ensure smooth application of the global configuration changes to the appliances at Company XYZ, the following precautions are taken:

Modifications to the local.cfg file at each appliance are forbidden.
An appliance in a lab environment is normally used for testing new configurations.
If it is necessary to test a modification on a production system, the administrator carries out the following actions:
- The administrator adds the modification to one of the POP configuration files and then loads the configuration on one of the appliances at that POP.
- If the results are acceptable after an observation period (minutes or hours, depending on the situation), the administrator introduces the modification into the common.cfg file.

Modification example modification

The administrator at Company XYZ wanted to add a particular IP address to the forwarding list that was specified in the common.cfg file.

The following setting was added to the configuration file for POP BBB:
```
config.transparency.bypass_ip.addrs += \\

132.55.55.10

\\
```
The administrator executed the config -n command on one of the appliances in POP bbb.

After the administrator verified that this setting solved a particular issue, this change was removed from the pop_bbb.cfg file and the IP address was added to the common.cfg file.