1 00:00:00,490 --> 00:00:07,960 The Cisco iOS is a single file that a router will load into RAM when it boots up typically from Flash. 2 00:00:08,860 --> 00:00:09,830 In this example, 3 00:00:09,850 --> 00:00:14,200 I've connected to an 1841 router 4 00:00:14,200 --> 00:00:19,560 sow Flash shows us the operating system stored in Flash. Show 5 00:00:19,660 --> 00:00:26,940 version shows us that this is the system file that the router is using. 6 00:00:27,730 --> 00:00:35,440 So the router loaded this image from Flash into RAM and that's the operating system that the router is 7 00:00:35,440 --> 00:00:36,370 currently using. 8 00:00:37,090 --> 00:00:43,480 Now, every operating system has a file system that's used for the organizational files. 9 00:00:43,990 --> 00:00:50,740 An operating system will typically store files in a file system which includes directories and files 10 00:00:50,740 --> 00:00:52,900 within directories. In windows 11 00:00:52,900 --> 00:00:57,390 as an example, you use a backslash to indicate directories. 12 00:00:58,060 --> 00:01:03,520 So as an example, in Windows, you would go to C colon backslash users, 13 00:01:03,910 --> 00:01:13,300 David in my example, desktop to view files on the desktop. Linux uses a forward slash for the directory 14 00:01:13,300 --> 00:01:15,160 structure. On a router 15 00:01:15,160 --> 00:01:18,370 Once again show flash shows us the flash 16 00:01:18,850 --> 00:01:25,390 DIR or DIR also shows us the contents of flash, notice flash colon forward slash. 17 00:01:27,250 --> 00:01:35,530 We also have the make directory option so we could create a directory called Test in Flash. 18 00:01:36,910 --> 00:01:43,690 So now when we use the command DIR we see this directory called test, which is very similar to 19 00:01:43,690 --> 00:01:45,420 what you typically find in Linux. 20 00:01:46,450 --> 00:01:54,370 I could then use the show running command or show running-config command and I could pipe that 21 00:01:55,620 --> 00:01:59,910 and in this case, I could redirect the output to flash 22 00:02:02,410 --> 00:02:10,380 test and then let's push it to a file called showrun.cfg. 23 00:02:11,230 --> 00:02:17,740 So now when I use the command DIR, I see the directory test, that I could use the command DIR 24 00:02:17,750 --> 00:02:19,930 flash test 25 00:02:21,400 --> 00:02:25,960 and we can see the showrun.cfg file stored in that directory. 26 00:02:28,070 --> 00:02:34,100 Notice the show Flash Command not only shows me the root directory but in this case, also shows me 27 00:02:34,100 --> 00:02:38,030 that file in this directory called Test. 28 00:02:39,140 --> 00:02:43,760 So notice DIR versus show Flash. 29 00:02:45,000 --> 00:02:51,180 So if you've used Linux, this is very similar to Linux commands or if you've used CMD in Windows, 30 00:02:51,510 --> 00:02:52,380 it's very similar. 31 00:02:54,210 --> 00:03:01,350 We can read the contents of that file by using the more command, so more flash:/test 32 00:03:02,740 --> 00:03:03,640 / 33 00:03:04,720 --> 00:03:12,280 shrn.cfg and that actually reads the contents of the file in that directory. 34 00:03:13,420 --> 00:03:20,350 So the Cisco iOS provides a feature called the Cisco iOS Integrated File System, or Cisco IFS. 35 00:03:21,010 --> 00:03:26,140 This system allows you to create, navigate and manipulate directories on a Cisco device. 36 00:03:26,770 --> 00:03:30,880 The directories that are available are dependent on the platform that you're using, 37 00:03:31,450 --> 00:03:35,070 file systems that you'll come across include flash memory file contents 38 00:03:35,070 --> 00:03:41,830 as I've demonstrated, you also have network file systems such as TFTP or Trivial File Transfer Protocol, 39 00:03:42,220 --> 00:03:47,230 RCP or Remote Copy and File Transfer Protocol or FTP. 40 00:03:48,460 --> 00:03:55,570 You also have other places where you can write data such as NVRAM, so a Cisco device could have 41 00:03:55,570 --> 00:03:56,780 a USB flash, 42 00:03:57,250 --> 00:03:59,710 It could have flash memory on the motherboard, 43 00:04:00,260 --> 00:04:03,430 it could have RAM, NVRAM and FTP.