Столкнулся со следующей проблемой:

Имею Cisco 2811 (10.10.17.29), на ней подняты GRE туннели, необходимо мониторить их состояние.
По snmp получаю информацию о всех интерфейсах, кроме одного туннеля.

То есть на маршрутизаторе:
Router#show snmp mib ifmib ifindex tunnel 900
Interface = Tunnel900, Ifindex = 82

То есть нужный мне туннель 900 имеет индекс 82.

На машине:
root@monitoring:~# snmpget -c public 10.10.17.29 -v 2c 1.3.6.1.2.1.2.2.1.2.82
IF-MIB::ifDescr.82 = No Such Instance currently exists at this OID

При этом "соседний" туннель с индексом 83:
root@monitoring:~# snmpget -c public 10.10.17.29 -v 2c 1.3.6.1.2.1.2.2.1.2.83
IF-MIB::ifDescr.83 = STRING: Tunnel800

Конфиги туннелей

interface Tunnel900
bandwidth 128
ip address 10.22.26.2 255.255.255.252
ip mtu 1500
snmp ifindex persist
keepalive 20 3
tunnel source 172.16.0.118
tunnel destination 172.17.0.1
end

interface Tunnel800
ip address 10.24.26.2 255.255.255.252
ip accounting output-packets
qos pre-classify
keepalive 7 3
tunnel source 10.22.45.2
tunnel destination 10.20.60.30
end

Router#show version
Cisco IOS Software, 2800 Software (C2800NM-ADVSECURITYK9-M), Version 12.4(8), RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2006 by Cisco Systems, Inc.
Compiled Mon 15-May-06 14:54 by prod_rel_team

ROM: System Bootstrap, Version 12.4(1r) [hqluong 1r], RELEASE SOFTWARE (fc1)

Router uptime is 9 weeks, 3 days, 23 hours, 31 minutes
System returned to ROM by power-on
System restarted at 17:36:48 KAMCH Fri Nov 28 2014
System image file is "flash:c2800nm-advsecurityk9-mz.124-8.bin"

This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to
export@cisco.com.

Cisco 2811 (revision 53.51) with 247808K/14336K bytes of memory.
Processor board ID FCZ0951724F
6 FastEthernet interfaces
2 Serial(sync/async) interfaces
8 Low-speed serial(sync/async) interfaces
1 Virtual Private Network (VPN) Module
DRAM configuration is 64 bits wide with parity enabled.
239K bytes of non-volatile configuration memory.
62720K bytes of ATA CompactFlash (Read/Write)

Configuration register is 0x2102

Подскажите, в чем может быть причина?