Posts Tagged ‘hp’

 

HP Procurve MSM422 / MAP-625 clients flow the dhcp server [solved]

A client was using the HP Procurve MSM422 / MAP-625 MultiService Access Point (wifi). It was being used in a rather crowded wifi environment and the problem was the wifi clients keept reconnecting and renegotioating so often that the DHCP server was overflowed, sometimes with DHCP requests every few seconds. They had been struggling with the problem for a couple of months and the focus was aimed at the DHCP requests.

It turned out that the problem was not in the DHCP negotiation at all, but was caused by the wireless clients that keept losing connection and each time when they reconnected a DHCP request was sent.

The client was misinformed, that 5 GHz band was prohibited in the country where it was set up (which is acutally not). So both radios (radio 1 and 2) where set to 2,4 GHz where radio 1 was set to 802.11n/b/g and radio 2 with 802.11b/g.

Furthermore, for radio 2 the value of the Antenna gain was set to the maximum which is 29 dBi in an attempt to boost the maximum power out of the system. However, this field works the opposite. In order to be regulatory compliant and not emit more than the allowed power, this field informs the system that it is connected to an antenna with 29 dBi gain, so to not emit illegal levels of power (output power + antenna gain), the system will reduce the actual output power (i.e. the power input to the antenna) by 29 dBi. But the system was using the internal antennas which, I guess, has more or less no antenna gain. This caused the system to actually emit -29 dBi, i.e. a very weak wifi signal.

The low power output made it hard for the wifi clients to “hear” the access point, which caused them constantly to lose connection and when reconnecting, they were sending a DHCP request, hogging down the DHCP server.

Solution:

  • Radio 1 was configured to use the 5 GHz band. This band is much less crowded than the 2,4 GHz band and the bandwidth is better, so when a client has the possibility, it is preferred if it can use the 5 GHz band.
  • Radio 2 was configured to use Internal Antenna with 0 dBi antenna gain.

Settings used when the problem was solved like this (click on the image to enhance it):

HP Procurve MSM422 MAP-625

HP Procurve MSM422 MAP-625

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Posted by on May 31st, 2017 No Comments

HP Compaq 6910p builtin 3G modem driver for Ubuntu

From Ubuntu 11.04 and onward there is no need for a driver to use the builtin 3G (WWAN) modem in the HP Compaq 6910p laptop computer. But by default the modem is soft blocked even though the radio lamp is on. The rfkill utility can be used to enable it:

$ rfkill list
0: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
1: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
2: hp-wifi: Wireless LAN
Soft blocked: no
Hard blocked: no
3: hp-bluetooth: Bluetooth
Soft blocked: no
Hard blocked: no
4: hp-wwan: Wireless WAN
Soft blocked: yes
Hard blocked: no

Enable it with rfkill unblock 4

$ rfkill unblock 4
$ rfkill list
0: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
1: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
2: hp-wifi: Wireless LAN
Soft blocked: no
Hard blocked: no
3: hp-bluetooth: Bluetooth
Soft blocked: no
Hard blocked: no
4: hp-wwan: Wireless WAN
Soft blocked: no
Hard blocked: no

Now click on the network manager icon in the top right bar of the screen and Activate mobile broadband and off you go!

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Posted by on August 12th, 2012 No Comments

Compaq HP 6910p with builtin 3G/GSM modem and Windows 7

A while ago I decided to start fresh with my HP Compaq 6910p laptop so I installed a new harddisk and Windows 7. My 6910p has an internal 3G/GSM modem (HS2300). When visiting the HP Support & Drivers page for the 6910p and Windows 7 I discovered there are no drivers or software for this 3G modem under Windows 7.

However, it turns out that both the driver and the connection manager for Vista works in Windows 7.

Download and install:

  1. HP WWAN Broadband Wireless drivers
  2. HP WWAN Connection Manager
  3. HP Broadband Wireless Client for Vodafone (or if there is one for your provider, pick that one instead)

If your 3G/GSM provider is Vodafone you’re done now. In my case I use the Swedish provider Tre (3). To use the Vodafone Connection Manager with another provider you must find out your providers APN and what number to dial (normally *99#). For Tre in Sweden the APN is "bredband.tre.se".

To use the connection manager with another provider just edit the connection profile that was installed by default and change (if necessary) the number to dial and the APN. To use Tre in Sweden the profile should look like this:

 

 

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Posted by on March 3rd, 2011 4 Comments