[c-nsp] Mysterious tunnel interfaces

Jay Nakamura zeusdadog at gmail.com
Thu Aug 12 13:53:51 EDT 2010


No HIMI.  Other than DMVPN, ZBFW, IOS content filtering, there is
nothing special going on here.  One T1 WIC, that's about it.

On Thu, Aug 12, 2010 at 1:48 PM, Matlock, Kenneth L
<MatlockK at exempla.org> wrote:
> Do you have any HIMI connections between the router, and a switchblade?
>
> Ken Matlock
> Network Analyst
> Exempla Healthcare
> (303) 467-4671
> matlockk at exempla.org
>
>
>
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Jay Nakamura
> Sent: Thursday, August 12, 2010 11:35 AM
> To: cisco-nsp
> Subject: Re: [c-nsp] Mysterious tunnel interfaces
>
> Mystery deepens.
>
> Router#conf t
> Enter configuration commands, one per line.  End with CNTL/Z.
> Router(config)#int tun0
> % This interface cannot be modified
> Router(config)#no int tun0
> % This interface cannot be modified
> Router(config)#int tun2
> % This interface cannot be modified
> Router(config)#int tun3
> % This interface cannot be modified
> Router(config)#^Z
> Router#sh ip pim tunnel
>
> Router#
>
> Nothing in "show run all" for these interfaces.
>
> I don't have multicast configured, or at least I haven't actively
> configured anything for it.  I haven't really had to do anything with
> Multicast so I am not familiar with it.
>
> I do have IOS content filtering installed/configured but I don't think
> that will do this.
>
> I do have ZBFW configured.
>
> I do not have VRF on this router.
>
> Here are some outputs of the interfaces
>
> Router#sh int tunn0
> Tunnel0 is up, line protocol is up
>  Hardware is Tunnel
>  Interface is unnumbered. Using address of Tunnel2 (172.16.0.1)
>  MTU 17912 bytes, BW 100 Kbit/sec, DLY 50000 usec,
>     reliability 255/255, txload 81/255, rxload 1/255
>  Encapsulation TUNNEL, loopback not set
>  Keepalive not set
>  Tunnel source 172.19.128.31
>  Tunnel protocol/transport multi-GRE/IP
>    Key disabled, sequencing disabled
>    Checksumming of packets disabled
>  Tunnel TTL 255, Fast tunneling enabled
>  Tunnel transport MTU 1472 bytes
>  Tunnel transmit bandwidth 8000 (kbps)
>  Tunnel receive bandwidth 8000 (kbps)
>  Last input never, output 17:22:42, output hang never
>  Last clearing of "show interface" counters never
>  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
>  Queueing strategy: fifo
>  Output queue: 0/0 (size/max)
>  5 minute input rate 0 bits/sec, 0 packets/sec
>  5 minute output rate 32000 bits/sec, 2 packets/sec
>     0 packets input, 0 bytes, 0 no buffer
>     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
>     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
>     95997 packets output, 26708838 bytes, 0 underruns
>     0 output errors, 0 collisions, 0 interface resets
>     0 unknown protocol drops
>     0 output buffer failures, 0 output buffers swapped out
> Router#sh int tunn2
> Tunnel2 is up, line protocol is up
>  Hardware is Tunnel
>  Internet address is 172.16.0.1/16
>  MTU 17916 bytes, BW 100 Kbit/sec, DLY 50000 usec,
>     reliability 255/255, txload 1/255, rxload 1/255
>  Encapsulation TUNNEL, loopback not set
>  Keepalive not set
>  Tunnel source 172.16.0.1
>  Tunnel protocol/transport multi-GRE/IP
>    Key disabled, sequencing disabled
>    Checksumming of packets disabled
>  Tunnel TTL 255, Fast tunneling enabled
>  Tunnel transport MTU 1476 bytes
>  Tunnel transmit bandwidth 8000 (kbps)
>  Tunnel receive bandwidth 8000 (kbps)
>  Last input never, output never, output hang never
>  Last clearing of "show interface" counters never
>  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
>  Queueing strategy: fifo
>  Output queue: 0/0 (size/max)
>  5 minute input rate 0 bits/sec, 0 packets/sec
>  5 minute output rate 0 bits/sec, 0 packets/sec
>     0 packets input, 0 bytes, 0 no buffer
>     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
>     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
>     0 packets output, 0 bytes, 0 underruns
>     0 output errors, 0 collisions, 0 interface resets
>     0 unknown protocol drops
>     0 output buffer failures, 0 output buffers swapped out
> Router#sh int tunn3
> Tunnel3 is up, line protocol is up
>  Hardware is Tunnel
>  Interface is unnumbered. Using address of Tunnel2 (172.16.0.1)
>  MTU 17912 bytes, BW 100 Kbit/sec, DLY 50000 usec,
>     reliability 255/255, txload 7/255, rxload 1/255
>  Encapsulation TUNNEL, loopback not set
>  Keepalive not set
>  Tunnel source 172.19.128.31
>  Tunnel protocol/transport multi-GRE/IP
>    Key disabled, sequencing disabled
>    Checksumming of packets disabled
>  Tunnel TTL 255, Fast tunneling enabled
>  Tunnel transport MTU 1472 bytes
>  Tunnel transmit bandwidth 8000 (kbps)
>  Tunnel receive bandwidth 8000 (kbps)
>  Last input never, output 05:17:13, output hang never
>  Last clearing of "show interface" counters never
>  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
>  Queueing strategy: fifo
>  Output queue: 0/0 (size/max)
>  5 minute input rate 0 bits/sec, 0 packets/sec
>  5 minute output rate 3000 bits/sec, 2 packets/sec
>     0 packets input, 0 bytes, 0 no buffer
>     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
>     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
>     111685 packets output, 18723536 bytes, 0 underruns
>     0 output errors, 0 collisions, 0 interface resets
>     0 unknown protocol drops
>     0 output buffer failures, 0 output buffers swapped out
> Router#sh ip int tun0
> Tunnel0 is up, line protocol is up
>  Interface is unnumbered. Using address of Tunnel2 (172.16.0.1)
>  Broadcast address is 255.255.255.255
>  MTU is 17856 bytes
>  Helper address is not set
>  Directed broadcast forwarding is disabled
>  Outgoing access list is not set
>  Inbound  access list is not set
>  Proxy ARP is enabled
>  Local Proxy ARP is disabled
>  Security level is default
>  Split horizon is enabled
>  ICMP redirects are never sent
>  ICMP unreachables are always sent
>  ICMP mask replies are never sent
>  IP fast switching is enabled
>  IP fast switching on the same interface is disabled
>  IP Flow switching is disabled
>  IP CEF switching is enabled
>  IP CEF switching turbo vector
>  IP Null turbo vector
>  VPN Routing/Forwarding "tunnel-group-ivrf"
>  Downstream VPN Routing/Forwarding ""
>  IP multicast fast switching is enabled
>  IP multicast distributed fast switching is disabled
>  IP route-cache flags are Fast, CEF
>  Router Discovery is disabled
>  IP output packet accounting is disabled
>  IP access violation accounting is disabled
>  TCP/IP header compression is disabled
>  RTP/IP header compression is disabled
>  Policy routing is disabled
>  Network address translation is disabled
>  BGP Policy Mapping is disabled
>  Input features: MCI Check
>  Output features: CCE Post NAT Classification, Firewall (firewall component)
>  WCCP Redirect outbound is disabled
>  WCCP Redirect inbound is disabled
>  WCCP Redirect exclude is disabled
> Router#sh ip int tun2
> Tunnel2 is up, line protocol is up
>  Internet address is 172.16.0.1/16
>  Broadcast address is 255.255.255.255
>  Address determined by unknown means
>  MTU is 1476 bytes
>  Helper address is not set
>  Directed broadcast forwarding is disabled
>  Outgoing access list is not set
>  Inbound  access list is not set
>  Proxy ARP is enabled
>  Local Proxy ARP is disabled
>  Security level is default
>  Split horizon is enabled
>  ICMP redirects are never sent
>  ICMP unreachables are always sent
>  ICMP mask replies are never sent
>  IP fast switching is enabled
>  IP fast switching on the same interface is disabled
>  IP Flow switching is disabled
>  IP CEF switching is enabled
>  IP CEF switching turbo vector
>  IP Null turbo vector
>  VPN Routing/Forwarding "tunnel-group-ivrf"
>  Downstream VPN Routing/Forwarding ""
>  Tunnel VPN Routing/Forwarding "tunnel-group-ivrf"
>  IP multicast fast switching is enabled
>  IP multicast distributed fast switching is disabled
>  IP route-cache flags are Fast, CEF
>  Router Discovery is disabled
>  IP output packet accounting is disabled
>  IP access violation accounting is disabled
>  TCP/IP header compression is disabled
>  RTP/IP header compression is disabled
>  Policy routing is disabled
>  Network address translation is disabled
>  BGP Policy Mapping is disabled
>  Input features: MCI Check
>  Output features: CCE Post NAT Classification, Firewall (firewall component)
>  WCCP Redirect outbound is disabled
>  WCCP Redirect inbound is disabled
>  WCCP Redirect exclude is disabled
> Router#sh ip int tun3
> Tunnel3 is up, line protocol is up
>  Interface is unnumbered. Using address of Tunnel2 (172.16.0.1)
>  Broadcast address is 255.255.255.255
>  MTU is 17856 bytes
>  Helper address is not set
>  Directed broadcast forwarding is disabled
>  Outgoing access list is not set
>  Inbound  access list is not set
>  Proxy ARP is enabled
>  Local Proxy ARP is disabled
>  Security level is default
>  Split horizon is enabled
>  ICMP redirects are never sent
>  ICMP unreachables are always sent
>  ICMP mask replies are never sent
>  IP fast switching is enabled
>  IP fast switching on the same interface is disabled
>  IP Flow switching is disabled
>  IP CEF switching is enabled
>  IP CEF switching turbo vector
>  IP Null turbo vector
>  VPN Routing/Forwarding "tunnel-group-ivrf"
>  Downstream VPN Routing/Forwarding ""
>  IP multicast fast switching is enabled
>  IP multicast distributed fast switching is disabled
>  IP route-cache flags are Fast, CEF
>  Router Discovery is disabled
>  IP output packet accounting is disabled
>  IP access violation accounting is disabled
>  TCP/IP header compression is disabled
>  RTP/IP header compression is disabled
>  Policy routing is disabled
>  Network address translation is disabled
>  BGP Policy Mapping is disabled
>  Input features: MCI Check
>  Output features: CCE Post NAT Classification, Firewall (firewall component)
>  WCCP Redirect outbound is disabled
>  WCCP Redirect inbound is disabled
>  WCCP Redirect exclude is disabled
>
>
>
>
> On Thu, Aug 12, 2010 at 9:39 AM, Luan Nguyen <luan at netcraftsmen.net> wrote:
>> I have those ISR2 (M1) as well as ASR1002 running DMVPN and don't have those
>> ghost tunnels.  Must be for some other services such as multicast.
>> Try to remove them with no interface tunnel 0, and I think the router will
>> tell you why you couldn't.
>>
>> Regards,
>>
>> -Luan
>>
>> -----Original Message-----
>> From: cisco-nsp-bounces at puck.nether.net
>> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Jay Nakamura
>> Sent: Wednesday, August 11, 2010 8:53 PM
>> To: cisco-nsp
>> Subject: [c-nsp] Mysterious tunnel interfaces
>>
>> I was working on a ISR 1941 with 15.0(1)M2.  I am running DMVPN on it
>> and using one tunnel interface.  (Tunnel 1).  No other tunnel
>> interfaces are configured on the router.  However when I do "show int
>> summary" I get this;
>>
>> #sh int summary
>>
>>  *: interface is up
>>  IHQ: pkts in input hold queue     IQD: pkts dropped from input queue
>>  OHQ: pkts in output hold queue    OQD: pkts dropped from output queue
>>  RXBS: rx rate (bits/sec)          RXPS: rx rate (pkts/sec)
>>  TXBS: tx rate (bits/sec)          TXPS: tx rate (pkts/sec)
>>  TRTL: throttle count
>>
>>  Interface              IHQ   IQD  OHQ   OQD  RXBS RXPS  TXBS TXPS TRTL
>> ------------------------------------------------------------------------
>> * GigabitEthernet0/0       0     0    0     0  6000    5  6000    5    0
>>  GigabitEthernet0/1       0     0    0     0     0    0     0    0    0
>> * Serial0/0/0              0     0    0     0  3000    3  2000    2    0
>>  NVI0                     0     0    0     0     0    0     0    0    0
>> * Tunnel0                  0     0    0     0     0    0     0    0    0
>> * Tunnel1                  0     0    0    10  1000    2  1000    2    0
>> * Tunnel2                  0     0    0     0     0    0     0    0    0
>> * Tunnel3                  0     0    0     0     0    0     0    0    0
>>
>> I thought may be something got left behind while I was monkeying
>> around in it so I reloaded the router and the tunnel 0,2,3 are still
>> there and it says it's up.   None of those interfaces are in the
>> startup or running-config.
>>
>> What is going on here?  My other routers with similar config on a 1841
>> with 12.4(15)T* doesn't have this issue.  It doesn't seem to be
>> affecting the routing of traffic but it's really bothering me.
>>
>> -Jay
>> _______________________________________________
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>>
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>>
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>> database 5358 (20100811) __________
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>> The message was checked by ESET NOD32 Antivirus.
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>> database 5360 (20100812) __________
>>
>> The message was checked by ESET NOD32 Antivirus.
>>
>> http://www.eset.com
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>> database 5360 (20100812) __________
>>
>> The message was checked by ESET NOD32 Antivirus.
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>
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