Portchannel не работает

[apache]

Привет, подскажите с проблемой. Заметил что один из линков в свитче не горит, начал копать. Итак есть свитч WS-C2960G-48TC-L, который подлкючен двумя портами:

!
interface GigabitEthernet0/3
 switchport trunk native vlan 999
 switchport mode trunk
 switchport nonegotiate
 channel-group 1 mode on
!
interface GigabitEthernet0/4
 switchport trunk native vlan 999
 switchport mode trunk
 switchport nonegotiate
 channel-group 1 mode on

в стек WS-C3850-24T в 20 е порты:

interface GigabitEthernet1/0/20
 description TO_2960_48
 switchport trunk native vlan 999
 switchport mode trunk
 switchport nonegotiate
 udld port aggressive
 channel-group 1 mode on

interface GigabitEthernet2/0/20
 description TO_2960_48
 switchport trunk native vlan 999
 switchport mode trunk
 switchport nonegotiate
 channel-group 1 mode on

Вот этот линк не горит на 2960:

ILO_SWITCH#sh int gi
ILO_SWITCH#sh int gigabitEthernet 0/3
GigabitEthernet0/3 is down, line protocol is down (notconnect)
  Hardware is Gigabit Ethernet, address is 3cdf.1e69.8503 (bia 3cdf.1e69.8503)
  MTU 1500 bytes, BW 10000 Kbit/sec, DLY 1000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Auto-duplex, Auto-speed, 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 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: 0/40 (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 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 1 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

А это вывод gi1/0/20 с 3850 стэка

CORE_2_3850#sh interfaces gigabitEthernet 1/0/20
GigabitEthernet1/0/20 is down, line protocol is down (notconnect)
  Hardware is Gigabit Ethernet, address is 80e8.6f62.a694 (bia 80e8.6f62.a694)
  Description: TO_2960_48
  MTU 1500 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)
  Auto-duplex, Auto-speed, 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 never, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/2000/0/0 (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, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 1 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

Можете сказать почему линк не горит?

 

[BackTrace]

Везде down кажет. Проблема на физическом уровне. Поменяй патч корд. Посмотри что будет. Либо порт горелый.

 

[apache]

Проверил, черт знает что было. Поставил новый патч корд - тоже самое. Поперетыкал в другие порты потом воткнул обратно и пошло. Может быть грязь или пыль в порту - свитч старенький.
Спасибо!!