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Day 15 183Figure 15-3Sample IOS Image Filenamec1841-ipbase-mz.123-14.T7.binFeature set - IP Base Version number -12.3(14)T7Platform - Cisco 1841 ISRFile format - m (runs in RAM)z (compressed or “zipped”)File extension -binary executableThe following details each part of the IOS filename shown in Figure 15-3:■■Platform: The first part, c1841, identifies the platform on which the image runs. In thisexample, the platform is a Cisco 1841.Features: The second part, ipbase, specifies the feature set. In this case, ipbase refers to thebasic IP internetworking image. Many feature sets are available:— i: Designates the IP feature set.— j: Designates the enterprise feature set (all protocols).— s: Designates a PLUS feature set (extra queuing, manipulation, or translations).— 56i: Designates 56-bit IPsec DES encryption.— 3: Designates the firewall/IDS.— k2: Designates 3DES IPsec encryption (168 bit).■Type: The third part, mz, indicates where the image runs (m for RAM) and that the image iszip compressed (z). Other possible codes include the following:— f: The image runs from Flash memory.— r: The image runs from ROM.— l: The image is relocatable.— x: The image is mzip compressed.■■Version: The fourth part, 123-14.T7, is the version number.Extension: The final part, bin, is the file extension. The .bin extension indicates that this is abinary executable file.Manage IOS ImagesAs any network grows, storing Cisco IOS Software images and configuration files on the centralTFTP server gives you control over the number and revision level of Cisco IOS images and configurationfiles that must be maintained. Figure 15-4 shows a sample topology with a TFTP server.