FEX Switch IOS Recovery Process

IA Switch - 6800IA 2T
Parent Switch - 6807XL

Problem: Lost IOS on IA Switch while adding it to the stack. I’m not exactly sure if it was shipped without an IOS or if I corrupted the IOS while adding it to the FEX stack.

Solution: Pull IA IOS image from parent switch via TFTP

My first reaction to a switch with a corrupted or deleted IOS is to run to the Cisco site, download the correct IOS, and then XMODEM transfer the IOS to the switch via a console/serial cable. So that’s what I set off doing only to be confused by the IOS offerings for the 6800IA switch. It seems they only had IOS versions for the 6T model and not the 2T. Even though I thought it was strange, I downloaded it anyway and attempted the XMODEM transfer.


switch: copy xmodem: flash:c6800-151.2sy4a.bin

File “xmodem:” successfully copied to “flash:c6800-151.2sy4a.bin”

switch: dir

List of filesystems currently registered:

bs[1]: (read-only)
flash[9]: (read-write)
xmodem[10]: (read-only)
null[11]: (read-write)
tftp[12]: (read-only)

switch: dir flash:
Directory of flash:/

2 -rwx 110674304 c6800-151.2sy4a.bin

10368K bytes available (108953K bytes used)

When attempting to boot the new image, I get this error:

switch: boot flash:/c6800-151.2sy4a.bin
Loading "flash:/c6800-151.2sy4a.bin"...flash:/c6800-151.2sy4a.bin: magic number mismatch: bad mzip file

After 3 attempts and 12 hours later, I decided to open a Cisco tac case because the transfer would be successful, but I would receive an error message when trying to boot the new IOS.

The TAC engineer told me that I was trying to install the wrong IOS. This IOS is for the parent 6807XL, not the 6800IA switch. Basically, he told me that I would have to retrieve the client switch IOS from the parent. Once I have the IOS I can install it via xmodem or tftp.

Here is the process:

1. Extract the IA IOS image from the Parent IOS image. Yes, you read that correctly. The IOS running image that is stored on the parent 6807 contains the IOS image for the IA client switches.

nacNcore#dir
Directory of bootdisk:/

1 -rw- 33554432 Jun 3 2016 11:50:38 -05:00 sea_console.dat
2 -rw- 33554432 Jun 3 2016 11:51:28 -05:00 sea_log.dat
4 drw- 0 Jun 3 2016 23:47:54 -05:00 onep
6 -rw- 11422 Jul 12 2016 16:50:22 -05:00 startup-config.converted_vs-20160712-215019
22 -rw- 112 Mar 20 2017 09:16:58 -05:00 info
24 -rw- 3306 Mar 12 2017 13:15:26 -05:00 debuginfo_mini_20170312-181527
25 -rw- 156744824 Mar 21 2017 10:13:36 -05:00 s2t54-ipservicesk9-mz.SPA.154-1.SY1.bin

 

nacNcore#archive tar /xtract microcode:FEX bootdisk:
c6800ia-universalk9-mz.152-4o.E2/ (directory)
extracting c6800ia-universalk9-mz.152-4o.E2/info (693 bytes)
extracting c6800ia-universalk9-mz.152-4o.E2/dc_default_profiles.txt (185024 bytes)
c6800ia-universalk9-mz.152-4o.E2/html/ (directory)
extracting c6800ia-universalk9-mz.152-4o.E2/html/foo.html (0 bytes)
extracting c6800ia-universalk9-mz.152-4o.E2/c6800ia-universalk9-mz.152-4o.E2.bin (18635776 bytes)
extracting info (112 bytes)

A new directory is created in the root of bootdisk:/ which I’ve highlighted in red. This will be where your IA image is located.

2. Copy the IA Client image to bootdisk:/ and give it a DIFFERENT NAME
nacNcore# copy bootdisk:c6800ia-universalk9-mz.152-4o.E2/c6800ia-universalk9-mz.152-4o.E2.NEW

3. Set up the IA Client and Parent for tftp by connecting a cable from the Yellow Mgmt port on the IA Client switch to a port on the Parent Switch. (Make sure whichever port you choose is configured for the vlan that matches the IP address that you’re going to give the Client IA switch) You can choose to use the IA Parent as the TFTP server, or you can copy the file to an external tftp server and use that instead. Again, check the vlan config on the port and make sure that you can reach the tftp server from that vlan.

On the Parent

If you’re using the parent switch as the tftp server, enter the following command:

tftp-server bootdisk:c6800ia-universalk9-mz.152-4o.E2.NEW

On The IA Client
You should be at the switch: prompt. Enter the following commands to prepare the switch:


switch: set IP_ADDR 10.25.254.50/255.255.255.255
switch: set DEFAULT_ROUTER 10.25.254.1

At this point you should be able to test connectivity to the tftp server by pinging it.

4. Copy the IA Client image from the Parent to the Client


switch: copy tftp://10.25.254.100/c6800ia-universalk9-mz.152-4o.E2.NEW flash:c6800ia-universalk9-mz.152-4o.E2.bin

5. Set the boot variable:


switch: BOOT=flash:/c6800ia-universalk9-mz.152-4o.E2.bin

6. Boot the IA switch by executing the boot command.


switch: boot

After doing some digging around, I was able to find this information on the cisco site. Here’s a link to the original.

Field Notice: FN – 63838 – Catalyst 6800 Instant Access Client Switch Fails to Boot During Installation or Upgrade – Image Recovery Required

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