controlling "background services", closing ports

[David Burns]

I recently installed fedora core 5 on  two systems.

Is the system/administration/services GUI thing discussed in the
documentation somewhere? (I can't seem to find anything except selinux.) I'd
like to know a bit more about what the consequences of turning off some
services might be. There is a terse description available in the tool, but
it doesn't make it clear what will happen if I turn 'em off. For instance, I
don't really know whether I need to "Listen and dispatch ACPI events from
the kernel. (acpid)" Hate to just turn them all off & see what breaks.

Also, I'm running nmap and lsof to try to figure out my open ports so I can
close those I don't need and tell the firewall about the ones I do need.


*nmap -sT -O mysystem ; *
Starting Nmap 4.03 ( http://www.insecure.org/nmap/ ) at 2006-06-19 17:06 HST
Interesting ports on lin...
(The 1666 ports scanned but not shown below are in state: closed)
PORT     STATE SERVICE
22/tcp   open  ssh
25/tcp   open  smtp
111/tcp  open  rpcbind
587/tcp  open  submission
603/tcp  open  mnotes            ??? What are these? How would I find out?
841/tcp  open  unknown          ???
868/tcp  open  unknown          ???
2049/tcp open  nfs
Device type: general purpose
Running: Linux 2.4.X|2.5.X|2.6.X
OS details: Linux 2.4.0 - 2.5.20, Linux 2.5.25 - 2.6.8 or Gentoo 1.2 Linux
2.4.19 rc1-rc7, Linux 2.6.3 - 2.6.10

Nmap finished: 1 IP address (1 host up) scanned in 2.290 seconds

Starting Nmap 4.03 ( http://www.insecure.org/nmap/ ) at 2006-06-19 17:06 HST
Interesting ports on ... <http://ao.soest.hawaii.edu/>;:
(The 1668 ports scanned but not shown below are in state: closed)
PORT     STATE SERVICE
22/tcp   open  ssh
111/tcp  open  rpcbind
640/tcp  open  unknown    ?
666/tcp  open  doom                *****???????????????!!!!*********** I did
not knowingly turn this on, don't know what service it is associated with.
773/tcp  open  submit
2049/tcp open  nfs
MAC Address: ... (Dell Computer)
Device type: general purpose
Running: Linux 2.4.X|2.5.X|2.6.X
OS details: Linux 2.4.0 - 2.5.20, Linux 2.4.7 - 2.6.11

Nmap finished: 1 IP address (1 host up) scanned in 2.670 seconds

lsof|grep LISTEN
portmap   1720       rpc    4u     IPv4       5412                 TCP
*:sunrpc (LISTEN)
rpc.statd 1739   rpcuser    7u     IPv4       5522                 TCP
*:36911 (LISTEN)
ypbind    1864      root    5u     IPv4       5771                 TCP
*:submit (LISTEN)
sshd      2114      root    3u     IPv6       6199                 TCP *:ssh
(LISTEN)
rpc.rquot 2131      root    4u     IPv4       6281                 TCP
*:entrust-sps (LISTEN)
rpc.mount 2165      root    7u     IPv4       6378                 TCP
*:mdqs (LISTEN)


There's some info in /etc/services, but not enough for me to "get it."

I hope this is the right forum for these questions. Thanks in advance for
any answers!
TDB

[Josh Bressers]

>  
>  I recently installed fedora core 5 on  two systems.
>  
>  Is the system/administration/services GUI thing discussed in the
>  documentation somewhere? (I can't seem to find anything except selinux.) I'd
>  like to know a bit more about what the consequences of turning off some
>  services might be. There is a terse description available in the tool, but
>  it doesn't make it clear what will happen if I turn 'em off. For instance, I
>  don't really know whether I need to "Listen and dispatch ACPI events from
>  the kernel. (acpid)" Hate to just turn them all off & see what breaks.
>  
>  Also, I'm running nmap and lsof to try to figure out my open ports so I can
>  close those I don't need and tell the firewall about the ones I do need.
>  
>  <...>
>  
>  I hope this is the right forum for these questions. Thanks in advance for
>  any answers!
>  TDB 
Hi David,

This list is for the discussion of fedora security issues, such as security
bugs.

If you're looking for help configuring your firewall there are several ways
to find community support detailed here:

http://fedora.redhat.com/participate/communicate/

Thanks and good luck,
-- 
Josh Bressers