[CentOS] Cannot open port 631 for Cups printer sharing

[b.j. mcclure]

On Mon, 2009-03-02 at 11:50 -0500, Roger Wells wrote:
> JohnS wrote:
> > On Mon, 2009-03-02 at 11:20 -0500, b.j. mcclure wrote:
> >   
> >> I have been trying to set up printer sharing on the LAN.All machines are
> >> CentOS 5.2 fully updated. The problem server is a fresh build.  The box
> >> it is replacing worked fine for many months.
> >> The problem appears to be a closed port 631 on the new box.  iptables
> >> and ip6tables are stopped as shown by the output below.  To confirm I
> >> was using nmap correctly I ran it against the old server first which
> >> shows 631 open.  No matter what I do to the new box (192.168.2.205) 631
> >> remains closed.  I was running it on the new box via ssh which I think
> >> eleminates any swithc/router issues.
> >>
> >> Any thoughts gladly accepted.  This must be something simple/stupid I
> >> have overlooked.  Not much hair left to pull out. ;-/
> >>     
> >
> > Do you have the Cups Service running? service cups status and service
> > hplip status.
> >
> >   
> I don't have an answer but I have to believe that your problem
> is related to mine (thread: cups & hp-toolbox)
> my machine: Linux rwells-rh 2.6.18-92.1.22.el5 #1 SMP Tue Dec 16 
> 12:03:43 EST 2008 i686 i686 i386 GNU/Linux
> [root at rwells-rh legacydp]# /sbin/service hplip status
> hpiod (pid 6422) is running...
> hpssd (pid 6427) is running...
> 
> [root at rwells-rh legacydp]# /sbin/service cups status
> cupsd (pid 6453) is running...
> 
> 10.40.90.14 is my IP address
> [roger at rwells-rh legacydp]$ nmap -sT -p 631 -PT 10.40.90.14
> 
> Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2009-03-02 11:34 EST
> Interesting ports on rwells-rh (10.40.90.14):
> PORT    STATE  SERVICE
> 631/tcp closed ipp
> 
> Interesting that when the local host address is used the port is open:
> [root at rwells-rh legacydp]# nmap -sT -p 631 -PT 127.0.0.1
> 
> Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2009-03-02 11:47 EST
> Interesting ports on localhost.localdomain (127.0.0.1):
> PORT    STATE SERVICE
> 631/tcp open  ipp
> 
> Nmap finished: 1 IP address (1 host up) scanned in 0.017 seconds
> 
> I hope that there are some clues here
> > JohnStanley
In my situation I ran nmap from the effected box via ssh, i.e., on the box in
question and 631 was still closed.  If it had been open locally but closed remotely 
I would have suspected a router/switch issue.   

CentOS 5.2, Linux 2.6.18-92.1.22.el5 x86_64 12:23:44 up 19:17, 2 users,
load average: 0.04, 0.02, 0.00