yes , but not redundancy , i want use two ports as one link , i mean i want Cisco see the 2 ports as one port to get 2 G instead 1 G. 

is this right ?

and im sorry for bad language , im not perfect in English .

Configuration is pretty straightforward on both SWs:

interface Port-channel_you pick the ID

switchport trunk allowed vlan all

switchport mode trunk

!

interface one

switchport trunk allowed vlan all

switchport mode trunk

 channel-group 1 mode active

!

interface two

switchport trunk allowed vlan all

 switchport mode trunk

 channel-group 1 mode active

But I suggest you to prior read some articles about LACP and Cisco port channel as you might damage your current network configuration.

thanks ,

i get this error message :

Command rejected: An interface whose trunk encapsulation is "Auto" can not be configured to "trunk" mode.

i try this steps before but the same error.

Just add switchport trunk encapsulation 802.1q before.

Unfortunately , i do the below steps , but still no any connection between two switches . when i type : show cdp nei   , no any link show !!!  what is this mean ?

Yes , the below is config for L3 switch (3750) for  :

interface Port-channel11
 switchport trunk encapsulation dot1q
 switchport mode trunk

interface GigabitEthernet1/0/21
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 11 mode active
!
interface GigabitEthernet1/0/22
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 11 mode active

if you need other switch config, feel free to tell me that.

Presumably the other switch is configured the same?

Can you post the results of the following:

#show int trunk

#show etherchannel summary

Thanks

Yes, other switch (3850) the same

Wesam_L3#sho int trunk

Port        Mode         Encapsulation  Status        Native vlan
Po1         on           802.1q         trunking      1
Po2         on           802.1q         trunking      1
Po3         on           802.1q         trunking      1
Po4         on           802.1q         trunking      1
Po6         on           802.1q         trunking      1

Port        Vlans allowed on trunk
Po1         1-4094
Po2         1-4094
Po3         1-4094
Po4         1-4094
Po6         1-4094

Port        Vlans allowed and active in management domain
Po1         1,10,20,30,40,50,60,70,80,90,100,200
Po2         1,10,20,30,40,50,60,70,80,90,100,200
Po3         1,10,20,30,40,50,60,70,80,90,100,200
Po4         1,10,20,30,40,50,60,70,80,90,100,200
Po6         1,10,20,30,40,50,60,70,80,90,100,200

Port        Vlans in spanning tree forwarding state and not pruned

Port        Vlans in spanning tree forwarding state and not pruned
Po1         1,10,20,30,40,50,60,70,80,90,100,200
Po2         1,10,20,30,40,50,60,70,80,90,100,200
Po3         1,10,20,30,40,50,60,70,80,90,100,200
Po4         1,10,20,30,40,50,60,70,80,90,100,200
Po6         1,10,20,30,40,50,60,70,80,90,100,200

Wesam_L3#sho etherchannel summary
Flags:  D - down        P - in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

Number of channel-groups in use: 10
Number of aggregators:           10

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(SU)         LACP      Gi1/0/1(P)  Gi1/0/2(P)  Gi1/0/3(P)
                                 Gi1/0/4(P)
2      Po2(SU)         LACP      Gi1/0/5(P)  Gi1/0/6(P)  Gi1/0/7(P)
                                 Gi1/0/8(P)
3      Po3(SU)         LACP      Gi1/0/9(P)  Gi1/0/10(P) Gi1/0/11(P)
                                 Gi1/0/12(P)
4      Po4(SU)         LACP      Gi1/0/15(P) Gi1/0/16(P)
5      Po5(SD)          -
6      Po6(SU)         LACP      Gi1/0/13(P) Gi1/0/14(P)
8      Po8(SD)          -
9      Po9(SD)          -
10     Po10(SD)         -
11     Po11(SD)        LACP      Gi1/0/21(D) Gi1/0/22(D)

Please help you.

Any update

am still waiting

From the last status message, it indicates port-channel 11 is (D) or down.  Can you shut down interface po11 on one of them and re-enable, and report what error messages there may be in the log, as to why the LACP wasn't enabled?

Also, it is odd that you don't get a CDP neighbor on the ports - it's possible you don't have CDP enabled; or there is a physical cabling issue (or SFP issue).  What do you get on gi 1/0/21 and 22 when you so "sh int status gi 1/0/21"?

Firstly the the current status unplug cable because avoid and loop may be accured, cause am in live inviroment , the the CDP is enabled but , the last status the CDP neighbor discover 2 cables , but there is loop or any thing because high ping and disconnection between switches ,

Wesam_L3#sho INTERfaces G1/0/21
GigabitEthernet1/0/21 is down, line protocol is down (monitoring)
  Hardware is Gigabit Ethernet, address is f025.72b7.a415 (bia f025.72b7.a415)
  MTU 1500 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)
  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 3w0d, output 1w2d, 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
     1 packets input, 64 bytes, 0 no buffer
     Received 1 broadcasts (0 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 1 multicast, 0 pause input
     0 input packets with dribble condition detected
     349149443 packets output, 44258136358 bytes, 0 underruns
     0 output errors, 0 collisions, 1 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
Wesam_L3#

port is down now to avoid any loop , this configuration is true ?

if you need any accesss to this switch let me know, i need solve this problem.