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Cisco Bug: CSCvu53797 - TRACK SR 688567427 : source loopback gets removed from flow-exporter, after reload. (Old 685779766)

Last Modified

Sep 19, 2020

Products (1)

  • Cisco ASR 1000 Series Aggregation Services Routers

Known Affected Releases

17.1.1

Description (partial)

Symptom:
na

Conditions:
summary:


ISSUE :
When the "source loopback" is configured under "netflow exporter", it gets removed after reload.
Analysis:
 >> Issue is too intermittent.
 >> currently issue does not occur at all either in ASR or CSR.
 >> customer says earlier issue used to occur every time they used to upgrade the the image to 17.1.1, in their ASRs.
 >> Now, customer has upgraded all its ASRs to 17.2.1 , but they dont see the issue in 17.2.1 at all.
 >> Soon they will be migrating to 17.3.1 EFT.
 
 Therefore after many discussions(internal and external) we have decided to share a debug image of EFT 17.3.1, to troubleshoot this issue, in future if it occurs.
 
 
++++++++++++++++++++++++++ Customer Evidence LOGs:++++++++++++++++++++++++++
 
 
 >> Before reload config:::::::::
 
 !
flow exporter NETFLOW-EXPORT-MAP
 destination 138.187.58.1
 source Loopback0              >>>>>>    source loopback 0 in flow-exporter.
 transport udp 9991
 template data timeout 30
 option interface-table
 option vrf-table
 option sampler-table
!
!
 
 >> After reload config:::::::::
 
 
++ After RELOAD, this error pops up :
source Loopback0                               
                ^
% Invalid input detected at '^' marker.

++ Flow exporter without "source loopback" after RELOAD.
!
!
flow exporter NETFLOW-EXPORT-MAP      >>>>>    No source loopback 0 in flow-exporter.
 destination 138.187.58.1
 transport udp 9991
 template data timeout 30
 option interface-table
 option vrf-table
 option sampler-table
!
!
------------------ show clock ------------------

20:38:41.519 MET Fri Jan 3 2020

------------------ show version ------------------
Cisco IOS XE Software, Version 17.01.01
Cisco IOS Software [Amsterdam], ASR1000 Software (X86_64_LINUX_IOSD-UNIVERSALK9-M), Version 17.1.1, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2019 by Cisco Systems, Inc.
Compiled Fri 22-Nov-19 03:43 by mcpre

Cisco IOS-XE software, Copyright (c) 2005-2019 by cisco Systems, Inc.
All rights reserved.  Certain components of Cisco IOS-XE software are
licensed under the GNU General Public License ("GPL") Version 2.0.  The
software code licensed under GPL Version 2.0 is free software that comes
with ABSOLUTELY NO WARRANTY.  You can redistribute and/or modify such
GPL code under the terms of GPL Version 2.0.  For more details, see the
documentation or "License Notice" file accompanying the IOS-XE software,
or the applicable URL provided on the flyer accompanying the IOS-XE
software.

ROM: IOS-XE ROMMON
mpa06ro1010olt uptime is 5 weeks, 1 day, 5 hours, 0 minutes
Uptime for this control processor is 5 weeks, 1 day, 5 hours, 3 minutes
System returned to ROM by Reload Command at 15:33:51 MET Thu Nov 28 2019
System restarted at 15:38:15 MET Thu Nov 28 2019
System image file is "bootflash:asr1000-universalk9.17.01.01.SPA.bin"
Last reload reason: Reload Command

 

++++++++++++++++++++++++++TAC's CALO LAB LOCAL TEST:(showing config sequence does not matter)++++++++++++++++++++++++++

Test Results from my local lab done on ASR1002-X:
(below test shows that even if loopback interface is not there, the flow-exporter contains the "source loopback" config).
This test is just to demonstrate that even if the "flow-exporter" config comes first in config (and by that time "loopback interface" config doesn't exist), even then this absence of "source loopback" under "flow exporter", should not occur.) and let's suppose due to remote config loading, the loopback config does not gets copied.
Hardware used (in my local lab): ASR10002-X
Image used : asr1002x-universalk9.16.05.01b.SPA.bin
Config before RELOAD:
lac(config)#do sh run | in Loop
source Loopback0.                                                                                           <<<<<<<<<<<    Flow-exporter
interface Loopback0
bgp router-id interface Loopback0.                                                                          <<<<<<<<<<<    BGP
ip nat log translations flow-export v9 udp destination 138.187.58.10 9991 source Loopback0.         <<<<<<<<<<<    NAT
lac(config)#
lac(config)#no int lo0                                                                                        <<<<<<<<<<< REMOVED THE LOOPBACK
lac(config)#do write                                                                                          <<<<<<<<<<< SAVED the config after removing the loopback interface.

++  Here we can check there was no interface before reload:
lac(config)#do sh ip int br
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet0/0/0   192.168.0.1     YES NVRAM  up                    up
GigabitEthernet0/0/1   unassigned      YES NVRAM  down                  down
GigabitEthernet0/0/2   unassigned      YES NVRAM  up                    up
GigabitEthernet0/0/3   unassigned      YES NVRAM  up                    up
GigabitEthernet0/0/4   unassigned      YES NVRAM  down                  down
GigabitEthernet0/0/5   unassigned      YES NVRAM  down                  down
GigabitEthernet0       10.197.175.245  YES NVRAM  up                    up
Virtual-Access1        unassigned      YES unset  down                  down
Virtual-Access2        unassigned      YES unset  up                    up
Virtual-Template1      unassigned      YES unset  down                  down
lac(config)#
++ And here we could see that the "router-id" config from BGP got removed just after I removed the "int loopback" config (even before reload), but we do still see the NAT and "flow exporter" config....
lac(config)#do sh run | s r b
router bgp 6500
bgp log-neighbor-changes
lac(config)#do sh run | s expor
flow exporter ABCD
flow exporter asb
source Loopback0
ip nat log translations flow-export v9 udp destination 138.187.58.10 9991 source Loopback0.
lac(config)#
++ Config sequence where we could see that before reload, the "interface loopback" config was configured after the "flow exporter"....
lac#sh run | in Loo
source Loopback0
ip nat log translations flow-export v9 udp destination 138.187.58.10 9991 source Loopback0
lac#sh ip int br
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet0/0/0   192.168.0.1     YES NVRAM  up                    up
GigabitEthernet0/0/1   unassigned      YES NVRAM  down                  down
GigabitEthernet0/0/2   unassigned      YES NVRAM  up                    up
GigabitEthernet0/0/3   unassigned      YES NVRAM  up                    up
GigabitEthernet0/0/4   unassigned      YES NVRAM  down                  down
GigabitEthernet0/0/5   unassigned      YES NVRAM  down                  down
GigabitEthernet0       10.197.175.245  YES NVRAM  up                    up
Loopback0              unassigned      YES unset  up                    up
Virtual-Access1        unassigned      YES unset  down                  down
Virtual-Access2        unassigned      YES unset  up                    up
Virtual-Template1      unassigned      YES unset  down                  down
lac#
lac#

!
!
!
!
!
flow exporter ABCD
!
!
flow exporter asb
source Loopback0
!
!
!
bba-group pppoe global
virtual-template 1
!
!
!
interface Loopback0
no ip address
!
interface GigabitEthernet0/0/0
ip address 192.168.0.1 255.255.255.0
negotiation auto
!
NOW I did reload::
++ After reload , I could see that the interface loopback was created because of the "flow exporter " config, even if the config was not there for that interface... (Notice that the IP is not there)
lac(config)#do reload
The following license(s) are transitioning, expiring or have expired.
Features with expired licenses may not work after Reload.
Feature: throughput_10g                 ,Status: transition, Period Left: 8  wks 2  days
Proceed with reload? [confirm]
*Mar  3 15:18:36.571: %SYS-5-RELOAD: Reload requested by console. Reload Reason: Reload Command.Mar  3 15:18:54.765 R0/0: %PMAN-5-EXITACTION: Process manager is exiting: process exit with reload chassis code
lac>en
Password:
lac#
lac#
lac#sh run | in Loo
source Loopback0.                                                                             >>>>>>> FLOW EXPORTER config still there with Loopback source..
interface Loopback0
ip nat log translations flow-export v9 udp destination 138.187.58.10 9991 source Loopback0
lac#sh ip int br
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet0/0/0   192.168.0.1     YES NVRAM  up                    up
GigabitEthernet0/0/1   unassigned      YES NVRAM  down                  down
GigabitEthernet0/0/2   unassigned      YES NVRAM  up                    up
GigabitEthernet0/0/3   unassigned      YES NVRAM  up                    up
GigabitEthernet0/0/4   unassigned      YES NVRAM  down                  down
GigabitEthernet0/0/5   unassigned      YES NVRAM  down                  down
GigabitEthernet0       10.197.175.245  YES NVRAM  up                    up
Loopback0              unassigned      YES unset  up                    up                   >>>>>>> NO IP ADDreSS.(gets automatically configured)
Virtual-Access1        unassigned      YES unset  down                  down
Virtual-Access2        unassigned      YES unset  up                    up
Virtual-Template1      unassigned      YES unset  down                  down
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