Do I need these ports open?

[Justin W]

Simon Slater wrote:
> 	Hi all,
>
> 	Just a quick question arising from following another thread.  Here is
> the result of nmap on a FC6 box:
>
> $ nmap localhost
>
> Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2007-04-18 14:10
> EST
> Interesting ports on localhost.localdomain (127.0.0.1):
> Not shown: 1670 closed ports
> PORT     STATE SERVICE
> 22/tcp   open  ssh
> 25/tcp   open  smtp
> 111/tcp  open  rpcbind
> 139/tcp  open  netbios-ssn
> 445/tcp  open  microsoft-ds
> 631/tcp  open  ipp
> 670/tcp  open  unknown
> 696/tcp  open  unknown
> 946/tcp  open  unknown
> 2049/tcp open  nfs
>
> Nmap finished: 1 IP address (1 host up) scanned in 2.036 seconds
> $ 
>
> 	What are the 3 "unknown" open ports?  Also I cannot find rpcbind,
> netbios-ssn nor microsoft-ds under System>Services.  What are these
> services for?
>
> Thanks
> Simon
>   

I don't have experience with the 3 unknown port numbers off the top of 
my head, but I do know that rpcbind is the port portmap uses to 
communicate rpc services over a network. NFS versions two and three 
depend on portmap being accessible, but version four doesn't require it 
(if I remember correctly, but having it open does help some tools you 
may want to use).  Ports 139 and 445 are both used by samba for windows 
sharing (139 being part of the NetBIOS naming system and 445 being the 
actual data port).

I hope this clears up some confusion for you.

Justin