[ipv6hackers] Scanning for IPv6 addresses embedding TCP/UDP service ports

Fabian Wenk fabian at wenks.ch
Sun Mar 17 20:51:44 CET 2013

Hello Jim

On 17.03.2013 18:53, Jim Small wrote:
> One more goof I made:
>> In regards to port 137, I'm pretty sure it only runs on UDP for name service
>> resolution.  But of course there may be exceptions.  Here is my recollection
>> of the legacy NetBIOS ports/services:
>> UDP/137 - WINS or NetBIOS Name Server
>> UDP/138 - NetBIOS datagram service
>> TCP/139 - NetBIOS session service
> Looking at this in context it doesn't make any sense to look
> for NetBIOS services in IPv6.  NetBIOS is an IPv4-only
> protocol that Microsoft has been trying to phase out for
> years.  There are no plans to extend it to IPv6 - IPv4 is the
> end of the road.  So scanning for it with v6 tools doesn't
> make sense.

Interesting, my Samba 3.6.12 installation on FreeBSD is also 
listening on IPv6 for TCP/139 and TCP/145:

fabian at superman:~ $ netstat -an | egrep "139|445"
tcp4       0      0 *.139            *.*               LISTEN
tcp4       0      0 *.445            *.*               LISTEN
tcp6       0      0 *.139            *.*               LISTEN
tcp6       0      0 *.445            *.*               LISTEN
fabian at superman:~ $

But for the UDP/137 and UDP/138 ports it is only listening on IPv4.


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