> Покажите show int по всей цепочке.
> Покажите show int по всей цепочке.

Многовато получится...

входной маршрутизатор
начало cisco c2911 area 1

show int g 0/2
GigabitEthernet0/2 is up, line protocol is up
  Hardware is CN Gigabit Ethernet, address is 30e4.dbad.6d12 (bia 30e4.dbad.6d12)
  Description: L2Tunn
  MTU 1600 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation 802.1Q Virtual LAN, Vlan ID  1., loopback not set
  Keepalive not set
  Full-duplex, 1000Mb/s, media type is RJ45
  output flow-control is unsupported, input flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:08, output 00:00:03, output hang never
  Last clearing of "show interface" counters 4d00h
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 1 packets/sec
     348917 packets input, 60738463 bytes, 0 no buffer
     Received 11588 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 11588 multicast, 0 pause input
     0 input packets with dribble condition detected
     113940 packets output, 13341549 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     11588 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

далее

show int g 0/2.203 (в сторону потребителя)
GigabitEthernet0/2.203 is up, line protocol is up
  Hardware is CN Gigabit Ethernet, address is 30e4.dbad.6d12 (bia 30e4.dbad.6d12)
  MTU 1600 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation 802.1Q Virtual LAN, Vlan ID  203.
  Keepalive set (10 sec)
  ARP type: ARPA, ARP Timeout 04:00:00
  Last clearing of "show interface" counters never

начало туннеля

show int lo 3
Loopback3 is up, line protocol is up
  Hardware is Loopback
  Description: L2tunnel
  Internet address is 10.11.0.3/32
  MTU 1514 bytes, BW 8000000 Kbit/sec, DLY 5000 usec,
     reliability 255/255, txload 1/255, rxload 0/255
  Encapsulation LOOPBACK, loopback not set
  Keepalive set (10 sec)
  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

выходной интерфейс маршрутизатора:

show int g 0/0
GigabitEthernet0/0 is up, line protocol is up
  Hardware is CN Gigabit Ethernet, address is 30e4.dbad.6d10 (bia 30e4.dbad.6d10)
  Description: cat3750
  Internet address is 192.168.252.34/30
  MTU 1600 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, media type is RJ45
  output flow-control is unsupported, input flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/3 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 2000 bits/sec, 4 packets/sec
  5 minute output rate 12000 bits/sec, 5 packets/sec
     365437516 packets input, 2206605592 bytes, 0 no buffer
     Received 3097634 broadcasts, 0 runts, 0 giants, 0 throttles
     6613 input errors, 0 CRC, 0 frame, 6613 overrun, 0 ignored
     0 watchdog, 3097624 multicast, 0 pause input
     0 input packets with dribble condition detected
     618169933 packets output, 1718299055 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

далее c3750 area 1

show system mtu

System MTU size is 1600 bytes
System Jumbo MTU size is 9000 bytes
Routing MTU size is 1600 bytes

интерфейс в сторону маршрутизатора

show int g 1/0/46
GigabitEthernet1/0/46 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is b8be.bfe4.cd42 (bia b8be.bfe4.cd42)
  Description: c2911
  Internet address is 192.168.252.33/30
  MTU 9000 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:04, output 00:00:01, 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: 0/40 (size/max)
  5 minute input rate 12000 bits/sec, 6 packets/sec
  5 minute output rate 4000 bits/sec, 6 packets/sec
     1616602606 packets input, 2070432497825 bytes, 0 no buffer
     Received 4510864 broadcasts (11 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 4510814 multicast, 0 pause input
     0 input packets with dribble condition detected
     898840653 packets output, 125315319269 bytes, 0 underruns
     0 output errors, 0 collisions, 7 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

исходящий интерфейс в сторону сети

show int g 1/0/49
GigabitEthernet1/0/49 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is b8be.bfe4.cd44 (bia b8be.bfe4.cd44)
  Description: main-fibre
  Internet address is 192.168.252.25/30
  MTU 9000 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not set
  Full-duplex, 1000Mb/s, link type is auto, media type is unsupported
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, 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: 0/40 (size/max)
  5 minute input rate 711000 bits/sec, 639 packets/sec
  5 minute output rate 714000 bits/sec, 632 packets/sec
     17799886662 packets input, 3364607960875 bytes, 0 no buffer
     Received 714950232 broadcasts (299 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 714950217 multicast, 0 pause input
     0 input packets with dribble condition detected
     18081704924 packets output, 4497666809808 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

транзитный c3720 area 2

show sys mtu

System MTU size is 1600 bytes
System Jumbo MTU size is 9000 bytes
Routing MTU size is 1600 bytes

входной инт
show int g 1/0/50
GigabitEthernet1/0/50 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is 64d8.14dd.ce46 (bia 64d8.14dd.ce46)
  Description: main-fibre
  Internet address is 192.168.252.26/30
  MTU 9000 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not set
  Full-duplex, 1000Mb/s, link type is auto, media type is unsupported
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:05, output 00:00:08, 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: 0/40 (size/max)
  5 minute input rate 712000 bits/sec, 630 packets/sec
  5 minute output rate 709000 bits/sec, 636 packets/sec
     6815508972 packets input, 1031691521055 bytes, 0 no buffer
     Received 19712848 broadcasts (23 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 19712837 multicast, 0 pause input
     0 input packets with dribble condition detected
     6584578715 packets output, 997543540736 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

выходной инт.
show int g 1/0/49
GigabitEthernet1/0/49 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is 64d8.14dd.ce45 (bia 64d8.14dd.ce45)
  Description: main-fibre
  Internet address is 192.168.252.22/30
  MTU 9000 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not set
  Full-duplex, 1000Mb/s, link type is auto, media type is unsupported
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, 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: 0/40 (size/max)
  5 minute input rate 4267000 bits/sec, 3366 packets/sec
  5 minute output rate 3890000 bits/sec, 3361 packets/sec
     35260504315 packets input, 4601148229191 bytes, 0 no buffer
     Received 114483165 broadcasts (79 IP multicasts)
     0 runts, 0 giants, 0 throttles
     137 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 114483155 multicast, 0 pause input
     0 input packets with dribble condition detected
     35156527233 packets output, 4595354668857 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

далее cat3750 area 3

входной интерфейс

show int g 1/0/49
GigabitEthernet1/0/49 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is 64d8.14dd.84c5 (bia 64d8.14dd.84c5)
  Description: main-fibre
  Internet address is 192.168.252.21/30
  MTU 9000 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not set
  Full-duplex, 1000Mb/s, link type is auto, media type is unsupported
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:07, output 00:00:01, output hang never
  Last clearing of "show interface" counters 1y4w
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 7417000 bits/sec, 3691 packets/sec
  5 minute output rate 4271000 bits/sec, 3368 packets/sec
     97789041578 packets input, 14849713935046 bytes, 0 no buffer
     Received 421544197 broadcasts (2740 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 421544175 multicast, 0 pause input
     0 input packets with dribble condition detected
     100762695305 packets output, 17730678410557 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

выходной интерфейс
show int g 1/0/43
GigabitEthernet1/0/43 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is 64d8.14dd.84c2 (bia 64d8.14dd.84c2)
  Description: to-c2921
  Internet address is 192.168.252.37/30
  MTU 9000 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters 1y4w
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 1143000 bits/sec, 203 packets/sec
  5 minute output rate 4194000 bits/sec, 548 packets/sec
     6134174680 packets input, 902348165488 bytes, 0 no buffer
     Received 5826685 broadcasts (7 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 5826456 multicast, 0 pause input
     0 input packets with dribble condition detected
     6993520061 packets output, 3010583920378 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

маршрутизатор area 3
входной инт.

show int g 0/1
GigabitEthernet0/1 is up, line protocol is up
  Hardware is CN Gigabit Ethernet, address is c471.fea8.8191 (bia c471.fea8.8191)
  Description: to-c3750
  Internet address is 192.168.252.38/30
  MTU 1600 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 1000Mb/s, media type is RJ45
  output flow-control is unsupported, input flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:03, output 00:00:00, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/12710 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 4306000 bits/sec, 553 packets/sec
  5 minute output rate 1128000 bits/sec, 203 packets/sec
     3289554779 packets input, 317746007 bytes, 0 no buffer
     Received 2473413 broadcasts, 0 runts, 0 giants, 0 throttles
     5054607 input errors, 0 CRC, 0 frame, 5054607 overrun, 0 ignored
     0 watchdog, 2473363 multicast, 0 pause input
     0 input packets with dribble condition detected
     3287603504 packets output, 2195762002 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     1 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

окончание туннеля
show int lo 4
Loopback4 is up, line protocol is up
  Hardware is Loopback
  Description: L2tunnel
  Internet address is 10.14.0.7/32
  MTU 1514 bytes, BW 8000000 Kbit/sec, DLY 5000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation LOOPBACK, loopback not set
  Keepalive set (10 sec)
  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

выходной интерфейс
show int g 0/2.203
GigabitEthernet0/2.203 is up, line protocol is up
  Hardware is CN Gigabit Ethernet, address is c471.fea8.8192 (bia c471.fea8.8192)
  Description: L2tun
  MTU 1600 bytes, BW 100000 Kbit/sec, DLY 100 usec,
     reliability 255/255, txload 10/255, rxload 1/255
  Encapsulation 802.1Q Virtual LAN, Vlan ID  203.
  Keepalive set (10 sec)
  ARP type: ARPA, ARP Timeout 04:00:00
  Last clearing of "show interface" counters never

show int g 0/2
GigabitEthernet0/2 is up, line protocol is up
  Hardware is CN Gigabit Ethernet, address is c471.fea8.8192 (bia c471.fea8.8192)
  MTU 1600 bytes, BW 100000 Kbit/sec, DLY 100 usec,
     reliability 255/255, txload 10/255, rxload 1/255
  Encapsulation 802.1Q Virtual LAN, Vlan ID  1., loopback not set
  Keepalive not set
  Full-duplex, 100Mb/s, media type is RJ45
  output flow-control is unsupported, input flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 20w1d, output 00:00:00, 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: 0/40 (size/max)
  5 minute input rate 1000 bits/sec, 2 packets/sec
  5 minute output rate 4103000 bits/sec, 363 packets/sec
     1608706588 packets input, 676636949 bytes, 0 no buffer
     Received 43 broadcasts, 0 runts, 0 giants, 0 throttles
     1144468873 input errors, 0 CRC, 0 frame, 1144468873 overrun, 0 ignored
     0 watchdog, 37 multicast, 0 pause input
     0 input packets with dribble condition detected
     1556471707 packets output, 667676332 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets
     16 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     2 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

все, дальше к потребителю