What are these specific port numbers for

[Sean]

Hi

Our local ISP just informed me that they are going to block ports,
137, 138, 139 & 445

could someone please explain the use and importance of these ports?

Thanks

 

[Kim Rubeck Jensen]

netbios-ns 137/tcp NETBIOS Name Service
netbios-ns 137/udp NETBIOS Name Service
netbios-dgm 138/tcp NETBIOS Datagram Service
netbios-dgm 138/udp NETBIOS Datagram Service
netbios-ssn 139/tcp NETBIOS Session Service
netbios-ssn 139/udp NETBIOS Session Service
microsoft-ds 445/tcp Microsoft-DS
microsoft-ds 445/udp Microsoft-DS

NetBios og Microsoft Directory Service...

/Rubeck

 

[Karl Diethrick]

Since these services will not work, you will not be able to utilize Microsoft File and Print Sharing over the Internet.  This is usually not desirable anyway.

Kim Rubeck Jensen wrote: netbios-ns      137/tcp    NETBIOS Name Service
netbios-ns      137/udp    NETBIOS Name Service
netbios-dgm     138/tcp    NETBIOS Datagram Service
netbios-dgm     138/udp    NETBIOS Datagram Service
netbios-ssn     139/tcp    NETBIOS Session Service
netbios-ssn     139/udp    NETBIOS Session Service
microsoft-ds    445/tcp    Microsoft-DS
microsoft-ds    445/udp    Microsoft-DS

NetBios og Microsoft Directory Service...

/Rubeck

"Sean" <[email protected]> wrote in message
news:[email protected]...

 

[Sean]

Thank you both for your help.