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Cat 6506 Goes into ROMMON

Jeremy Phillips

I know this is going to sound rediculous but I need a second opinion.  I have a Cat6506.  There were 2 Sup 720 in it for redundancy.  They told me they had problems with this thing in the past needing to go out and reboot the machine.  I need to go out periodically because it goes into ROMMON.  I type boot and it comes back up.  One time though neither one would reboot.  I had to take a third one out there and reconfigure it.  Now it is starting to do the same thing.  One thing I did notice is they never connected it to an UPS.  It is plugged strait into the wall with power going to two outlets.  I am beginning to think there are spikes in the power occurring and this is sending it into ROMMON.  Can someone confirm this?

6 Replies 6

Reza Sharifi
Hall of Fame Expert Hall of Fame Expert
Hall of Fame Expert

Power fluctuation can make the router reboot many time and at some point the router ends up in Rommon mode.

I recommend getting PDU and connecting the PDU to the wall and the switch to the PDU.  If you have redundant power supplies, I recommend getting 2 PDUs (one on each side of the rack) and connect the power supplies to 2 different PDUs.



Just to add, have you checked the boot parameters? When we lost power on our 6509, it keeps going to ROMMON. We installed the 2nd 720, but still booting to ROMMON even with normal reload. Thats when we realized the boot parameters.

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Raju Sekharan
Cisco Employee
Cisco Employee

In addition to checking power isseus at site, Please check the following

1. Check if ithere is any crashinfo present in bootdisk,sup-bootdisk,slvaebootdisk,slave-supbootdisk

2. Also check what is reported in in following outputs

a . remote command switch show nvlog

b.remote command standby-sp show nvlog

3. Check if there is any fabric issues

Show fabric channel-counters

4. Check if the boot parameters are correct

Show bootvar



Thank you both for your replies.  I did check the bootvar and this is what I got:

SSHS-IDF13-6506-195#sho bootvar

BOOT variable =

CONFIG_FILE variable does not exist

BOOTLDR variable =

Configuration register is 0x2102

The nvlog showed that I restarted it, but that was all. The fabric channel-counters did not show any errors.  There is no crashinfo.  Could not get the command to work.

This did lead me to another discussion that showed a link for configuring the boot variable.  Now I have this:

SSHS-IDF13-6506-195#sho bootvar

BOOT variable = disk0:s72033-pk9sv-mz.122-17d.SXB11.bin,12

CONFIG_FILE variable does not exist

BOOTLDR variable =

Configuration register is 0x2102

Standby is not present.

SSHS-IDF13-6506-195#sho run

Building configuration...


boot system disk0:s72033-pk9sv-mz.122-17d.SXB11.bin

I am hoping this will fix this but I still need to get them to purchase a new PDU for this switch.

You need Boot system command for the router  to boot from disk0

I have seen "boot system disk0:s72033-pk9sv-mz.122-17d.SXB11.bin" giving troubles some times

it is better to use like this

boot system flash disk0:s72033-pk9sv-mz.122-17d.SXB11.bin


Jeremy Phillips

I will do that tomorrow. Thank you.

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