Hiroshi Takada (Computer Engineering & Consulting, Ltd.)
Masayuki Okada (Japan Network Information Center (JPNIC))


Telecommunication carriers are exposed to various kinds of attacks all the time and there is a wide range of countermeasures depending on the attack. In the past, viruses and worms would not only threaten end users, but also cause traffic congestion making the network unstable for all users. Network link becoming congested has been a regular occurrence.

As a counter-measure for these problems, we come up with solutions such as filtering certain communications. However in the past we have had a basic rule to follow in Japan - privacy of communications. So, it was difficult for telecommunication carriers to filter out certain communications.

For now, we're allowed to take measures, especially if it's clearly regarded as a legitimate action based on reasons such as consensus building between telecommunication carriers and the administration of communication.

As well-known examples, there are measures taken against spam mail such as OP25B, and more recently measures related to UDP/123 have been taken to prevent NTP attacks.

This time I would like to focus on IP53B, which is being taken to prevent attacks using DNS (Port 53) - Recently DNS (Port 53) is beginning to be used as a stepping stone. I would like to exchange information about influences which are particular to port 53, what kinds of people are affected and so on.

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Last-modified: (201d)