Hello fellow blog reader, after long gap I'm going to write this thread regarding the basic Juniper command and configuration. I try to include as much as troubleshooting/configuration command during day to day work.
I would like to thank to Srijan pointing the error on LACP command.

1. Set username for login
root@jpudasaini#set system root-authentication encrypted-password
New password:
Retype new password:

root@jpudasaini#set system login user jay full-name jaypudasaini uid 400 class super-user authentication encrypted-password


2. Hostname configuration.
root@switch#set system host-name jpudasaini
root@jpudasaini#

3. Set Tacplus authentication for juniper switch.
root@jpudasaini# set system authentication-order tacplus
root@jpudasaini# set system authentication-order password
root@jpudasaini# set system root-authentication encrypted-password "you password here"
root@jpudasaini# set system tacplus-server 10.10.10.10(your tacplus server IP) secret "your server password here"
root@jpudasaini#set system tacplus-options service-name test

4. Configuration VLAN(Group)
root@jpudasaini#set vlans Cust-Fiber vlan-id 500-550
root@jpudasaini#set vlans Cust-Wireless vlan-id 551-575
    single vlan
root@jpudasaini#set vlans Cust-A vland-id 25

5. Trunk Port Configuration
root@jpudasaini#set interfaces ge-0/0/9 description connect-to-sw2
root@jpudasaini#set interfaces ge-0/0/9 unit 0 family ethernet-switching port-mode trunk
root@jpudasaini#set interfaces ge-0/0/9 unit 0 family ethernet-switching vlan members Cust-Fiber

6. Access Port Configuration
root@jpudasaini#set interfaces ge-0/0/0 description Link-to-sw3
root@jpudasaini#set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode access
root@jpudasaini#set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members 25

7. Port Channel Configuration
root@jpudasaini#set chassis aggregated-devices ethernet device-count 10
root@jpudasaini#set interfaces ae0 description TR-2-Jpudasaini-Sw2
root@jpudasaini#set interfaces ae0 aggregated-ether-options lacp active
root@jpudasaini#set interfaces ae0 unit 0 family ethernet-switching port-mode trunk
root@jpudasaini#set interfaces ae0 unit 0 family ethernet-switching vlan members Cust-Fiber
root@jpudasaini#set interfaces ae0 unit 0 family ethernet-switching vlan members Cust-Wireless

8. Port Channel Assign to the Physical Port
root@jpudasaini#set interfaces ge-0/0/16 description test-sw1
root@jpudasaini#set interfaces ge-0/0/16 ether-options 802.3ad ae0
root@jpudasaini#set interfaces ge-0/0/17 description test-sw1
root@jpudasaini#set interfaces ge-0/0/17 ether-options 802.3ad ae0

9. Configuration management IP for switch.
root@jpudasaini#set interfaces vlan unit 20 family inet address 10.10.10.11/24

10. Configuration snmp.
root@jpudasaini#set snmp name Test-SNMP
root@jpudasaini#set snmp description test-sw2
root@jpudasaini#set snmp location "Jpudasaini-NOC"
root@jpudasaini#set snmp contact "system@jpudasaini.com.np"
root@jpudasaini#set snmp client-list list0 10.10.10.0/24
root@jpudasaini#set snmp community ax3R5vgW authorization read-only
root@jpudasaini#set snmp community ax3R5vgW client-list-name jpudasaini

11. Enable LLDP
root@jpudasaini# set protocols lldp interface all
root@jpudasaini#set protocols lldp-med interface all

12. Configure port as L3
root@jpudasaini#set interface ge-0/0/23 unit 0 family ethernet-switching port-mode trunk
root@jpudasaini#set interface ge-0/0/23 unit 0 family ethernet-switching vlan member 25
root@jpudasaini#set vlan Mgmt vlan-id 25
root@jpudasaini#set vlan Mgmt l3-interface vlan.25
root@jpudasaini#set interface vlan.250 family inet address xxx.xxx.xxx.xxx

13.Rate Limit
 Configure the policer

root@jpudasaini# set firewall policer Policer_2M if-exceeding bandwidth-limit 1M
root@jpudasaini# set firewall policer Policer_2M if-exceeding burst-size-limit 2k
root@jpudasaini# set firewall policer Policer_2M then discard

Configure the firewall filter

root@jpudasaini# set firewall family ethernet-switching filter Limit term 1 then accept
root@jpudasaini# set firewall family ethernet-switching filter Limit term 1 then policer Poicer_2M

Apply filter on interface (can be any interface as required)

root@jpudasaini# set interface ge-0/0/24.0 family ethernet-switching filter input Limit

Note: Remember that EX series switches apply rate limit only on ingress. 

Command:
interface fa0/2
switchchport mode access
switchport access vlan 30
switchport protected

Sometime I need to analyze network traffic from remote switch. Thus RSPAN is life saver. Go to the site and capturing the packets and analyze the packets is very time consuming. So here a small tutorial which explain how to configure packets with RSPAN.

SW1(This is the remote switch, Which is the source for our packets.)

sw1(config)#vlan 444
sw1(config-vlan)#remote-span
sw1(config)#monitor session 1 source interface Fa1/0/1 - 16
sw1(config)#monitor session 1 destination remote vlan 444



SW2(The destination switch where you going sniff the packets send my remote switch on case sw1.)
sw2(config)#vlan 444
sw2(config-vlan)#name RSPAN_VLAN
sw2(config-vlan)#remote-span

sw2(config)#monitor session 1 destination interface Gi0/17
sw2(config)#monitor session 1 source remote vlan 444

Now you can capture remote packets in port 17.

All these tutorial tested on cisco 3750 switch.

Step1:
Fist of all create tftp server in one of the updated IOS switch.
sw2(config)#tftp-server c2950-i6k2l2q4-mz.121-22.EA14.bin

Step2:
Then go to the remote switch where you want to upgrade IOS with new version.

sw1#copy tftp: flash:
Address or name of remote host [100.100.255.47]?
Source filename [100.100.255.47]? c2950-i6k2l2q4-mz.121-22.EA14.bin
Destination filename [c2950-i6k2l2q4-mz.121-22.EA14.bin]?
Accessing tftp://100.100.255.47/c2950-i6k2l2q4-mz.121-22.EA14.bin...
Loading c2950-i6k2l2q4-mz.121-22.EA14.bin from 100.100.255.47 (via Vlan2): !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[OK - 3722814 bytes]

3722814 bytes copied in 143.124 secs (26011 bytes/sec)

Step3.
Check your copied IOS in the switch.

sw1(config)#do dir flash:
Directory of flash:/

    2  -rwx         864  Mar 01 1993 05:45:31 +05:45  vlan.dat
    3  -rwx       13499  Sep 23 2014 22:17:39 +05:45  config.text
    4  -rwx        1952  Sep 23 2014 22:17:39 +05:45  private-config.text
    5  -rwx     3722112  Mar 01 1993 07:33:24 +05:45  c2950-i6k2l2q4-mz.121-22.EA12
    6  -rwx        5871  Mar 01 1993 06:18:00 +05:45  sw1-config
    7  -rwx          43  Mar 01 1993 07:37:36 +05:45  env_vars
    8  -rwx     3722814  Sep 24 2014 12:30:41 +05:45  c2950-i6k2l2q4-mz.121-22.EA14.bin
  305  -rwx        5168  Mar 01 1993 08:37:25 +05:45  running-config1
  306  -rwx        1048  Sep 23 2014 22:17:39 +05:45  multiple-fs

7741440 bytes total (263680 bytes free)

Step5.
Verify the IOS if corrupted while copying form remote system to the destination system.

sw1#verify /md5 flash:c2950-i6k2l2q4-mz.121-22.EA14.bin
.............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................Done!
verify /md5 (flash:c2950-i6k2l2q4-mz.121-22.EA14.bin) = 8d3250ee253b81b7fe2762e281773fbc

Step6.
Now boot system

sw1(config)#boot system c2950-i6k2l2q4-mz.121-22.EA14.bin

Step7.
Write into the memory, otherwise your system may not boot from the new IOS or if you removed working IOS you system may not found any IOS.

sw1#wr memory
Building configuration...
[OK]

sw1#reload
System configuration has been modified. Save? [yes/no]: y
Building configuration...
[OK]

Step8.
Now check your system boot from new IOS

sw1#sh ver | inc image
System image file is "flash:/c2950-i6k2l2q4-mz.121-22.EA14"
Proceed with reload? [confirm]

How to recover extra space in 2950 switch.

In case you may have little space in switch, your new IOS have "3722814" size and switch only left "2220544" bytes free, in my case I don't need html file so I delete it form the switch.
sw1#dir flash:
Directory of flash:/

    2  -rwx     3722112  Apr 08 2013 11:13:12 +05:45  c2950-i6k2l2q4-mz.121-22.EA12
    3  -rwx         796  Mar 01 1993 05:45:28 +05:45  vlan.dat
    4  drwx        4224  Mar 14 2008 11:52:14 +05:45  html
   79  -rwx        1048  Sep 23 2014 17:05:12 +05:45  multiple-fs
   81  -rwx       12534  Sep 23 2014 17:05:12 +05:45  config.text
   83  -rwx        1958  Sep 23 2014 17:05:12 +05:45  private-config.text

7741440 bytes total (2220544 bytes free)

sw1#delete /f /r flash:html
Delete filename [html]? 

This tutorial assumed you already create Hotspot in your router. If you don't know how to create a hotspot in Mikrotik router, click here and create the Hotspot. .

After successfully creating the hotspot server go to "Files" Menu of  the main Window of Mikrotik router Copy "hotspot" folder into your PC.

1. The following instructions appear:
  The system has been interrupted prior to initializing the
   flash filesystem.  The following commands will initialize
   the flash filesystem, and finish loading the operating
   system software:
       flash_init
       load_helper
       boot
   switch:

2. Now follow the following command

switch: flash_init
switch: dir flash
switch: rename flash:config.text flash:config.old
switch: boot

3. Enter "n" at the prompt to start the setup program

--- System Configuration Dialog ---
   At any point you may enter a question mark '?' for help.
   Use ctrl-c to abort configuration dialog at any prompt.
   Default settings are in square brackets '[]'.
   Continue with configuration dialog? [yes/no]: n

    !--- Press Return or Enter.
 
    Switch>
 
    !--- The Switch> prompt is displayed.

      switch>en
      switch#

4. Type rename flash:config.old flash:config.text to rename the configuration file with its original name.

    Switch#rename flash:config.old flash:config.text
                Destination filename [config.text]
    Switch#

5. Copy the configuration file into memory

       Switch#copy flash:config.text system:running-config

6. Change the password


      Switch#configure terminal
      Switch(config)#no enable secret
      Switch(config)#enable secret Cisco
      Switch(config)#end

7. Write the into the memory.

          Switch#write memory
                 Building configuration...
                 [OK]
        Switch#

To reset password of  2970 Switch, power off the switch and press MODE button then power it on, take a look at the SYS led when it glows green leave the mode button. To recover the password click here.

Now your are in switch: prompt mode.
switch: flash_init
switch: dir flash:

switch: delete flash:config.text
switch: delete  flash:vlan.dat