Tag Archives: tcpdump

The IT Detective Agency: Internet Explorer cannot display https web page, part II

Intro They say when it rains it pours. As a harassed It support specialist its tempting to lump all similar-looking problems that come across your desk at the same time in the same bucket. This case shows the shallowness of … Continue reading

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The IT Detective Agency: last letter of attachment name is missing!

Intro Today we bring you an IT whodunit thriller. A user using Lotus Notes informs his local IT that a process that emails SQL reports to him and a few others has suddenly stopped working correctly. The reports either contain … Continue reading

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The IT Detective Agency: intermittent web page not found error

Intro One of the high arts of IT is system integration, and an important off-shoot of this is acquisitions. We are involved in integrating a new location, which, unfortunately, we do not yet have full access to. The local networking … Continue reading

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The IT Detective Agency: ARP Entry OK, PING not Working

Intro Yes, the It detective agency is back by popular demand. This time we’ve got ourselves a thriller involving a piece of equipment – a wireless LAN controller, WLAN – on a directly connected network. From the router we could … Continue reading

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Internet Service Providers Block TCP Port 22 or Do They?

Intro The original premise of this article is that some Internet Service Providers were seen to block TCP port 22, used by ssh and sftp. However, as often happens during active IT investigations, this turns out to be completely wrong. … Continue reading

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Swapping Servers while Preserving IPs – What Might Go Wrong

The Setup I had this experience last week. I needed to swap a virtual server in place of a physical server. I had all the access I needed on both servers to do the necessary network changes, which is how … Continue reading

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