2. In what cases would you find it useful to use the ‘cc’, ‘bcc’ and ‘reply all’ functions of email?

CC (Carbon Copy):
The ‘cc’ email function is useful when an email being sent to a recipient may also hold some informational value, or interest, though most likely to a lesser extent than that of the main recipient. Including your own email address (whether it be the same as the sending address or otherwise) can be useful as a form of reminder.

BCC (Blind Carbon Copy):
One of the most clever aspects of email is the ‘bcc’ function although it probably isn’t used as commonly as the ‘cc’ function. This ‘blind’ function allows a recipient to be included but without other recipients knowing. There are two situations where this is particularly useful; when sending to a large volume of recipients it is good netiquette to hide everyone’s addresses using this method, and when dealing with sensitive situations where it is a good idea to include a hidden recipient (perhaps a superior staff member or co-worker in a work situation) who is then aware of the situation and how you have handled it.

Reply All:
The ‘reply all’ function is especially useful for when a group email has been sent out but omits an essential detail which must then be sent to all original recipients. This function is also useful if emails are being used to organise a meeting or gathering, since the recipients can reply to all and everyone then knows who will be attending, or not.

1. What information about a user’s email, the origin of a message, and the path it took, can you glean from an email message?

To most people, an email contains the usual information displayed by your average email application; sender, receiver, subject, message body, and so on, yet each email contains much more data.

Each email message contains metadata known as “headers”, containing information such as the IP addresses involved in the email “transaction”, the type of content included (for example, plain text, multipart or by attachment type) and the original arrival time to name a few.

Tip: Microsoft Outlook 2007 allows you to view the email headers by right-clicking an email in your Inbox and selecting Message Options. By looking at the header data you can gather an idea as to where it originated from.

An example of email headers (addresses censored)

Email headers are not immune to hackers. I have had to take precautions when writing code for websites (primarily PHP) to ensure steps are taken to prevent hackers (and botnets) from injecting false headers into email messages. Many website forms actually send the data you submit via email, and if the data is not validated correctly, a window of opportunity presents itself to hackers who can then insert additional headers and/or content. For example, a poorly designed form may have the potential to deliver spam to thousands (or more) of email addresses by a hacker who injects a header containing additional email addresses. I’ve simplified the scenario but it gives you an idea of the vulnerabilities that can be present. An example and detailed explanation of PHP header injection can be found here.

Traceroute provides a fascinating insight into the paths which internet page queries take via various paths around the globe.

Interestingly, a recent edition of The Age reported that several underwater telephone and internet cables had been damaged, prompting me to think that this would impact on the traceroute results, especially since one of the cables links 33 countries (The Age, 2008).

TraceRoute to 134.7.179.53 [curtin.edu.au]

Hop  (ms)  (ms)  (ms)     IP Address  Host name
1  11  6  6    72.249.0.65    -
2  7  6  6    209.249.122.73  209.249.122.73.available.above.net
3  7  6  6    64.125.26.213  ge-2-0-0.mpr2.dfw2.us.above.net
4  12  13  11    64.125.26.134  so-1-1-0.mpr4.iah1.us.above.net
5  42  42  42    64.125.25.18  so-1-1-0.mpr4.lax9.us.above.net
6  44  43  42    64.124.200.234    -
7  193  192  193     202.158.194.157  so-4-0-0.bb1.b.syd.aarnet.net.au
8  214  223  233     202.158.194.33  so-2-0-0.bb1.a.mel.aarnet.net.au
9  223  223  222     202.158.194.17  so-2-0-0.bb1.a.adl.aarnet.net.au
10 25 254  249     202.158.194.5  so-0-1-0.bb1.a.per.aarnet.net.au
11  250  250  249     202.158.198.178  gigabitethernet0.er1.curtin.cpe.aarnet.net.au
12  251  250  249     202.158.198.186  gw1.er1.curtin.cpe.aarnet.net.au
13  Timed out  Timed out  Timed out         -
14  Timed out  Timed out  Timed out         -
15  Timed out  Timed out  Timed out         -
16  256  262  257     134.7.179.53  -
Trace complete

Result: The traceroute above indicates 16 hops were taken to travel from the http://network-tools.com site to curtin.edu.au

The average time taken was just over 1.7 seconds. The IP address of the hostname is curtin.edu.au is identified as: 134.7.179.53. I used the Ping utility on the http://network-tools.com site to ping the curtin.edu.au address. This took roughly the same time (averaged over 10 pings) of 253.1 ms.

I attempted to traceroute the curtin.edu.au address from my computer but initially received the following problem:

tracert 134.7.179.53

Tracing route to 134.7.179.53 over a maximum of 30 hops
1     2 ms    <1 ms    <1 ms  mygateway1.ar7 [10.1.1.1]
2    18 ms    17 ms    17 ms  meb4.ba.optusnet.com.au [198.142.129.4]
3    17 ms    17 ms    18 ms  meb4-unk1-447.gw.optusnet.com.au [198.142.57.65]
4    19 ms  mygateway1.ar7 [10.1.1.1]  reports: Destination protocol unreachable.
Trace complete.

It turned out my firewall was preventing a successful traceroute call so after adjusting the firewall settings, a positive traceroute result was achievable.

tracert 134.7.179.53

Tracing route to 134.7.179.53 over a maximum of 30 hops
1    <1 ms    <1 ms    <1 ms  mygateway1.ar7 [10.1.1.1]
2    18 ms    17 ms    17 ms  meb4.ba.optusnet.com.au [198.142.129.4]
3    16 ms    17 ms    17 ms  meb4-unk1-447.gw.optusnet.com.au [198.142.57.65]
4    18 ms    19 ms    19 ms  sun2-ge12-0-0-821.gw.optusnet.com.au [211.29.156.13]
5    18 ms    19 ms    17 ms  sun5-unk8-1.gw.optusnet.com.au [198.142.160.230]
6    18 ms    19 ms    19 ms  61.88.144.117
7   200 ms   202 ms   102 ms  61.88.226.121
8    64 ms    64 ms    63 ms  61.88.226.121
9    64 ms    64 ms    64 ms  AARNET.o6ssc76fe.optus.net.au [61.88.166.134]
10    64 ms    64 ms    64 ms  ge-1-0-3.bb1.a.per.aarnet.net.au [202.158.198.1]
11    63 ms    64 ms    64 ms  gigabitethernet0.er1.curtin.cpe.aarnet.net.au [202.158.198.178]
12    68 ms    65 ms    63 ms  gw1.er1.curtin.cpe.aarnet.net.au [202.158.198.186]
13     *        *        *     Request timed out.
14     *        *        *     Request timed out.
15     *        *        *     Request timed out.
16    65 ms    65 ms    66 ms  134.7.179.53
Trace complete.

The average time taken was less than a second from my computer to curtin.edu.au. The two traceroute calls made the same number of hops, which I found unusual since I thought being in Australia, my computer would take less hops to reach the curtin.edu.au address.

Next time I can’t reach a site, I’ll be using traceroute and/or ping to check whether it’s down or if it’s just me!

Reference:

Web partially restored after cable cut, 21 December 2008, viewed 21 December 2008, <http://www.theage.com.au/news/technology/web/web-partially-restored-after-cable-cut/2008/12/21/1229794224240.html>.

FTP (File Transfer Protocol) is an Internet tool I use daily within my day job. Whilst FTP is a straightforward concept – that is, transferring files to and from a server – it is such a powerful tool that I can only imagine how difficult life would be without it!

I have used FTP clients such as Fetch and Transmit on the Mac platform previously, but my favourite is FireFTP, a Firefox extension that allows you to perform FTP transfers from within the browser. I’ve also written applescripts which upload and download material from FTP sites either automatically or on an ad hoc basis.

For this task I installed the FileZilla client on Windows XP.

The Filezilla Interface

Task: According to the README file located on the FTP site identified in the task: CAPITALIZATION MATTERS.

Telnet was not something I was familiar with prior to this task, although it does appear to be something which I may have unknowingly used back in school when computers networks were still relatively raw.

I decided to undertake this task on a PC running Windows XP and found that it took a little bit of effort to locate a Telnet client. It appears that Vista comes with an install link of some sort to get Telnet set up. Using XP however, I found telnet was accessible using a utility called HyperTerminal – already installed, but I wanted to try telnet using a more “user-friendly” interface. I settled with PuTTY a telnet/SSH client. The interface was surprisingly easy to use, considering I was expecting something quite primitive given the simplicity of the PuTTY website.

Telnet was relatively easy to use. I would actually prefer to use this for my local library since their website can be a little problematic in my experience – unfortunately they don’t appear to offer it (perhaps due to the more secure options now available). The ability to email search results was a handy feature although I’m unsure I would use it in a real life scenario, as was the ability to drill down to in depth details of a particular library item.

The Telnet animation at the address towel.blinkenlights.nl was a clever use of Telnet but in this day of high tech animation it didn’t hold my attention long enough to watch it all the way through. Once upon a time it may have been ground breaking, providing an example of how alternative thinking can cause breakthroughs in technology usage. Innovative thoughts like the blinkenlights example show how not all potential uses for an application are obvious at first look.