It had been a while since I had messed with wireless. But since I just brought a fancy new antenna, it was time to investigate some exciting new stuff. Well, as with most things I find exciting they usually end up costing me heaps of time 
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Once I had setup the new antenna I wanted to have a look at the performance difference, which is a bit flaky from the network manager. But I noticed as I started messing with some commands something happened which was unexpected. I started getting the dreaded “wireless dropout” that occurs infrequently at about 20 second intervals just to piss me off. I tried to retrace my steps to find out what I had changed and ended up spending a whole day looking for the solution. It turns out that with the “cool” new commands that I had learned to do things like:
- restart the network interfaces
- lift the interfaces up and down
- list other networks in my area and
- finally, one to show the status of my own network
Even though it was nice to be able to type a few words and have the interfaces restart afresh I was leaning toward this being the problem. Then, I remembered that orignally when I was having these sorts of problems in the begining, I downloaded an app called Wicd! This was the solution for my problems orignally and funnily enough did the same again 
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Well, there were some good things to come from this “journey”?? Not sure what they were, but here is a list of the commands that I found and are pretty handy! Also, remember Wicd might also be a simple solution for you?
Show status of “my” wireless interface: ‘iwconfig ath0‘
xxxxxxxx@HAL:~$ iwconfig ath0
ath0 IEEE 802.11g ESSID:"xxxxx" Nickname:""
Mode:Managed Frequency:2.442 GHz Access Point: 00:xx:xx:xx:xx:8B
Bit Rate:36 Mb/s Tx-Power:18 dBm Sensitivity=1/1
Retry:off RTS thr:off Fragment thr:off
Power Management:off
Link Quality=58/70 Signal level=-36 dBm Noise level=-94 dBm
Rx invalid nwid:52311 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
Show list of all wireless broadcasts within range: ‘iwlist ath0 scan‘
xxxxxxxx@HAL:~$ iwlist ath0 scan
ath0 Scan completed :
Cell 01 - Address: 00:xx:xx:xx:xx:8B
ESSID:"xxxxx"
Mode:Master
Frequency:2.442 GHz (Channel 7)
Quality=59/70 Signal level=-36 dBm Noise level=-95 dBm
Encryption key:on
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
48 Mb/s; 54 Mb/s
Extra:bcn_int=100
IE: IEEE 802.11i/Encryption here 
Group Cipher : TKIP
Pairwise Ciphers (1) : TKIP
Authentication Suites (1) : PSK
Cell 02 - Address: 00:xx:xx:xx:xx:78
ESSID:"xxxxx"
Mode:Master
Frequency:2.442 GHz (Channel 7)
Quality=28/70 Signal level=-67 dBm Noise level=-95 dBm
Encryption key:on
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
48 Mb/s; 54 Mb/s
Extra:bcn_int=100
IE: IEEE 802.11i/Encryption here
Group Cipher : TKIP
Pairwise Ciphers (1) : TKIP
Authentication Suites (1) : PSK
Restart all network interfaces
xxxxxxxx@HAL:~$ sudo /etc/init.d/networking restart
. So I did some reading and it turns out that the fastest and most used is PPTP for remote connections. However, IpSec seems to be the obvious choice for bridging locations such as office_1 to office_2. The security features of PPTP are not that strong, due to the high level of abstraction before the encryption takes place. IpSec is a much lower and “raw” layer which has much stronger security features, but suffers on speed because of this.
