Tag Archives: network

Allegro nie działa – analiza techniczna (atak DDOS)

Tym razem mała analiza dotycząca aktualnego padu allegro.pl. Serwis nie odpowiada: $ telnet allegro.pl 80 Trying 72.52.5.208… Connected to allegro.pl. Escape character is '^]'. GET / HTTP/1.0 Connection closed by foreign host. Jak widać na załączonym poniżej obrazku obsługę ruchu … Continue reading

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Multicast streaming analysis using tcpdump

If you want to track network problems with IPTV streaming you may take a look at IGMP messages exchange in your network. IGMP is used to register clients for multicast streaming. You may record whole stream using Wireshark of course, … Continue reading

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DHCP command line diagnostics – an aternative to Wireshark

I do prefer small command line utilities over heavy GUI tools and use then whenever possible. Command line has better post-processing possibilities (you can pipe output to other tools) and automation (you can easily script them). Small example of network … Continue reading

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[SOLVED] "too many jobs" mysterious bug in libupnp

One of my responsibilities in current project is analysis of "hard" bugs – problems that are not easily reproducible or the cause is so mysterious that remains unresolved (or worse: resolved – not reproducible) even after few iterations developer <-> … Continue reading

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Monitor Multicast UDP Traffic

Recently I was diagnosing problems with missing multicast data for some system. Multicast send UDP packets from single source to many registered subscribers. IPTV is using this feature to stream video for example. For unicast (1-1) transmissions you can use … Continue reading

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