ISR G2 Routers - Tunnel Interface

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Mar 29th, 2010
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Does anyone know why there are 3 tunnel interfaces enabled by default? They don't show up on the running config, only shows up when you issue a show ip int brief. I can't seem to remove it at all. It looks like it's not being advertised out anywhere but I still would like to know how to remove it as our global policy uses tunnel0-2 for GRE backup tunnels.



Tunnel0                    172.16.0.1      YES unset  up                    up     
Tunnel1                    172.16.0.1      YES unset  up                    up     
Tunnel2                    172.16.0.1      YES unset  up                    up  


Cisco IOS Software, C2900 Software (C2900-UNIVERSALK9-M), Version 15.0(1)M1, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2009 by Cisco Systems, Inc.
Compiled Wed 02-Dec-09 15:23 by prod_rel_team


ROM: System Bootstrap, Version 15.0(1r)M1, RELEASE SOFTWARE (fc1)


dlt01r uptime is 1 day, 23 hours, 7 minutes
System returned to ROM by power-on
System image file is "flash0:c2900-universalk9-mz.SPA.150-1.M1.bin"



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Cisco CISCO2901/K9 (revision 1.0) with 2576383K/45056K bytes of memory.
Processor board ID FTX140880QM
4 FastEthernet interfaces
2 Gigabit Ethernet interfaces
2 Serial(sync/async) interfaces
1 Channelized E1/PRI port
DRAM configuration is 64 bits wide with parity enabled.
255K bytes of non-volatile configuration memory.
4099032K bytes of ATA System CompactFlash 0 (Read/Write)



License Info:


License UDI:


-------------------------------------------------
Device#   PID                   SN
-------------------------------------------------
*0        CISCO2901/K9          FTX140880QM   




Technology Package License Information for Module:'c2900'


----------------------------------------------------------------
Technology    Technology-package          Technology-package
              Current       Type          Next reboot 
-----------------------------------------------------------------
ipbase        ipbasek9      Permanent     ipbasek9
security      None          None          None
uc            uck9          Permanent     uck9
data          None          None          None


Configuration register is 0x2102

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Paolo Bevilacqua Tue, 03/30/2010 - 10:45
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Perhaps these are leftovers of previous configurations, due to a cosmetic bug.

Richard Bradfield Tue, 07/26/2011 - 20:48
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Did you ever get this problem fixed.

I have exactly the same problem

Plays havoc with our monitoring tool  as these interfaces are always showing up as over 100% utilisation!

johng231 Fri, 07/29/2011 - 10:51
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No. Cisco I think had said it was just part of the new version and there's nothing that can be done to remove them. We just ignored the interfaces and used the next sequence available.

rseiler Wed, 08/17/2011 - 21:06
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This is because you have an WCCP L3 GRE connected device. Recent IOS exposes the actual GRE tunnels that are used, previous releases hid them. This is useful for troubleshooting but a little disconcerning if you are not used to it. This stumped me for awhile, TAC had no idea.


You can get rid of them, however. The same IOS version you are running allows WCCP L2 redirection, which is *much* lower CPU overhead on both the WAE and the router. Just change the WAE configuration to use WCCP L2 for both ingress and egress and the tunnels will go away. Obviously, the WAE has to be L2 adjacent to an interface on the router.


Let me know if I'm on track here or if you are experiencing a completely different issue.


/Rick

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