I need the default password for ProCurve J4900B

there is no default password on an HP switch. You can clear the password on a switch by powering on a switch and make sure it is done booting (you should see all the port light up for a short time in order down the switch when it is booted) then take a paper clip and press the clear button on the front of the switch. that will clear any password left on the switch

We need more information to answer your question.

HP ProCurve Switch 2600 Series Installation and Getting Started Guide

Page 1-9

ftp://ftp.hp.com/pub/networking/software/59908821-0904.pdf

Clear Button

This button is used for these purposes:

Deleting Passwords - When pressed by itself for at least one second, the button deletes any switch console access passwords that you may have configured. Use this feature if you have misplaced the password and need console access.

HP 2626 do not have a default IP address, you have to set the IP address on an enterprise class business switch. You can find the manual for your switch at http://www.hp.com

There is no default password. If a password is set you either need to know it or have physical access to the switch

This link should tell you the answer. http://h30499.www3.hp.com/t5/Switches-Hubs-Modems-Legacy-ITRC/Clear-password-in-Procurve-2650/td-p/4598369#.U0sRNfldUok

There should be no default IP address on a 2626 switch. HP Procurve switches are setup by default to get an IP address by DHCP. To execute the factory default reset on the switch, perform these steps:

1. Using pointed objects, simultaneously press both the Reset and Clear buttons on the front of the switch.
2. Continue to press the Clear button while releasing the Reset button.
3. When the Self Test LED begins to blink, release the Clear button. The switch will then complete its self test and begin operating with its configuration restored to the factory default settings.
   

Be aware, using these instructions will wipe out any configuration you have on the switch

Good Luck

Hi,

check out the HP website. HP has a lot of very good resources for all of their products. here is the link:
http://www.hp.com/rnd/support/manuals/2650_6108.htm

hope I could help you out on this.

What do you need it configured to support? Multiple subnets? VoIP support?
Here's an example to support 2 subnets, VLAN 1 Data and VLAN 2 Voice. This switch is the VLAN router for the site and it is also the default gateway for all the devices on the network.

show running-config

Running configuration:

; J4899A Configuration Editor; Created on release #H.10.50

hostname "HP 2650 dot 11 layer 3"
snmp-server contact "Your contact info here"
snmp-server location "Server Rack - Upper Switch"
time timezone -5
time daylight-time-rule Continental-US-and-Canada
interface 49
name "Uplink to HP2650 port 49 - 192.168.105.12"
flow-control
exit
interface 50
name "Uplink to HP2650 port 49 - 192.168.105.13"
flow-control
exit
ip routing
timesync sntp
snmp-server community "public" Unrestricted
vlan 1
name "Data"
untagged 1-46
ip address 192.168.105.11 255.255.255.0
ip helper-address 10.50.3.2
tagged 49-50
no untagged 47-48
exit
vlan 2
name "Voice"
untagged 47-48
ip address 10.50.3.11 255.255.255.0
ip helper-address 10.50.3.2
tagged 1-46,49-50
exit
ip route 0.0.0.0 0.0.0.0 192.168.105.1
spanning-tree Always turn on Spanning Tree
spanning-tree priority 0 This switch is the master Spanning Tree operator.
password manager
password operator

operate a factory reset to make sure it is hardware Fault: press reset and clear simultaneously for 3 good seconds then release Clear, when Switch fault and ports start flashing let go of Reset button. If Fault Light still on, contact HP Support.
BE WARNED, this operation will remove passwords and configuration.