Why does my new ISR4331 router have two different images installed?

[rweir0001]

We just bought a Cisco ISR4331 router and there appears to be both IOS and IOS XE software on it. The boot path is for the IOS XE image file, but why are there two different images? Is it normal for these model of routers to come with both an IOS and IOS XE image? If the boot path is for the IOS XE image, when it is time to upgrade the software, should I just upgrade to another IOS XE version? My old 1941 router only has an IOS image so I am a little confused.

This is from the sho version command on the 4331 router:

Router#sho vers
Cisco IOS XE Software, Version 03.13.04.S - Extended Support Release
Cisco IOS Software, ISR Software (X86_64_LINUX_IOSD-UNIVERSALK9-M), Version 15.4(3)S4, RELEASE SOFTWARE (fc3)

System image file is "bootflash:/isr4300-universalk9.03.13.04.S.154-3.S4-ext.SPA.bin"

[Mark Malone · Accepted solution]

Hi

actually ios-xe image name includes the ios equivalent version in its file name , if you type dir as below example 3.16.2 is the ios-xe and the equivalent In ios is 15.5.3, theres only 1 image that's just the way Cisco have named them

Full file name

 isr4300-universalk9.03.16.02.S.155-3.S2-ext.SPA.bin

Directory of bootflash:/

   11  drwx            16384  Mar 22 2016 20:58:30 +00:00  lost+found
128513  drwx             4096   May 4 2016 16:53:03 +00:00  .prst_sync
224897  drwx             4096  Mar 22 2016 20:59:01 +00:00  .installer
32129  drwx             8192   Jul 8 2016 10:36:44 +00:00  tracelogs
   13  -rwx              480  Mar 22 2016 20:59:12 +00:00  tracelogs.807
144577  drwx             4096   May 4 2016 16:53:15 +00:00  core
321281  drwx             4096  Mar 22 2016 21:22:21 +00:00  .rollback_timer
   14  -rw-               30   Jul 8 2016 09:31:20 +00:00  throughput_monitor_params
   15  -rw-        470602752   May 4 2016 16:46:55 +00:00  isr4300-universalk9.03.16.02.S.155-3.S2-ext.SPA.bin

[rweir0001]

Thanks, Mark!