'bgp bestpath as-path ignore' in ASR 1006

[irfan1729]

Hi all,

I want to configure BGP to ignore as-path for best path selection in  ASR 1006 router . But in BGP configuration mode, It is not listing as-path option. It is showing as unrecognized command.

RTR1(config-router)#bgp bestpath ?
  compare-routerid  Compare router-id for identical EBGP paths
  cost-community    cost community
  igp-metric        igp metric
  med               MED attribute
  prefix-validate   Prefix origin validation
RTR1(config-router)#

IOS version details are as follows:

RTR1#sh ver
Cisco IOS Software, IOS-XE Software (X86_64_LINUX_IOSD-ADVENTERPRISEK9-M), Version 15.2(4)
S, RELEASE SOFTWARE (fc4)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2012 by Cisco Systems, Inc.
Compiled Mon 23-Jul-12 20:02 by mcpre
IOS XE Version: 03.07.00.S
Cisco IOS-XE software, Copyright (c) 2005-2012 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
RTR1 uptime is 31 weeks, 17 hours, 51 minutes
Uptime for this control processor is 31 weeks, 17 hours, 53 minutes
System returned to ROM by reload
System restarted at 23:29:29 IST Sat Apr 6 2013
System image file is "bootflash:/asr1000rp2-adventerprisek9.03.07.00.S.152-4.S.bin"
Last reload reason: PowerOn

Any help would be much appreciated.

Thanks all in advance

[Peter Paluch · Accepted solution]

Irfan,

The command may be hidden but perhaps it can be accepted if you type it in in its entirety. See here, this is a 2691 12.4(15)T13 IOS:

R1(config)#router bgp 1
R1(config-router)#bgp bestpath ?
  compare-routerid  Compare router-id for identical EBGP paths
  cost-community    cost community
  med               MED attribute
R1(config-router)#bgp bestpath as-path ?
% Unrecognized command
R1(config-router)#bgp bestpath as-path ignore ?
% Unrecognized command
R1(config-router)#bgp bestpath as-path ignore 
R1(config-router)#do show run | sec router bgp
router bgp 1
 no synchronization
 bgp log-neighbor-changes
 bgp bestpath as-path ignore
 no auto-summary

Best regards,

Peter

[irfan1729]

Thanks Peter.

That command was hidden. It works now.

But why was that commands hidden ?

Irfan

[Peter Paluch]

Irfan,

My personal opinion: Some commands may be hidden in the IOS if their use is generally discouraged and not meant to be used by common customers but only by TAC engineers to circumvent certain problems or modify a protocol's operation in a way that can make its behavior strongly divergent from the standard. No one is going to take any responsibility for what happens if you use hidden or undocumented commands - and that is why Cisco does not want them to be generally known. It is for both our and Cisco's protection.

There are numerous lists of undocumented IOS commands, e.g.:

http://willy.boerland.com/myblog/book/print/199

http://willy.boerland.com/myblog/the_undocumented_commands

You could certainly use Google to find other similar lists.

Best regards,

Peter