I’ve run into a perplexing network issue that I’ve not been able to solve.
I had a network application that worked fine until an update. Then all of a sudden it quit connecting. It works with Mac, and Winblows, but no longer Linux. In this case, I use Playonlinux. The obvious reaction is that it is an application problem. But upon further review it appears to be a port issue. I ran some packet traces and noticed that during the login sequence, I get responses that certain ports of mine are unreachable. I tried turning the firewall off within Yast2, and it made no difference. I then started manually adding port exceptions in the firewall and one by one those went away, but the list was up to about 10 and it was growing. Which lead me to the question why are these ports even close by default? I thought unless blocked should default to open.
I did an nmap and here is what popped up:
nmap -p 30000-60000 localhost
Starting Nmap 6.25 ( http://nmap.org ) at 2014-05-06 21:56 MST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.0000070s latency).
Not shown: 29995 closed ports
PORT STATE SERVICE
30000/tcp open unknown
30001/tcp open pago-services1
32400/tcp open unknown
So you can see they are specifically closed! How can I make sure a range of port are open for UDP service? I tried to make a custom rule that says 30000-60000, but that is invalid apparently.
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Thank you very much for the response. So when nmap shows those ports “closed”, it doesn’t mean they are shut down, just that nothing is using them then? I am not an expert, so I thought when it said closed, it meant they had to be opened in order to use them. What lead me to believe this line of thinking was right, was when I specifically allowed certain ports to be opened, that the error on that particular port went away, but then another showed up.
It still seems like what you say is correct, since it DID work fine for months until they did an update. Unfortunately since it is using a wrappers type program they hide behind “we don’t support” Linux.
AFAIK only the firewall would block any port. you tried to shut the firewall down and still couldn’t connect. do you know which is the ip:port where your app Playonlinux tries to connect to? can you reach it using another protocol?
A closed port is not a blocked port. It generally means there is no application listening on it.Refer to ‘man nmap’
A closed port is accessible (it receives and responds to Nmap probe packets), but there is no
application listening on it. They can be helpful in showing that a host is up on an IP address (host
discovery, or ping scanning), and as part of OS detection. Because closed ports are reachable, it
may be worth scanning later in case some open up. Administrators may want to consider blocking such
ports with a firewall. Then they would appear in the filtered state, discussed next.
I didn’t take it that far. I have come to the conclusion it HAS to be a software issue. I have not changed my system, it worked for months fine, they pushed a new update on me, and it quit working. I was hoping I could work around it, but they have slammed the door in my face with, “we do not support linux”. They will not help in any way. I guess I could get some hack tools to portscan myself, but if memory serves, that shows “open” ports for something that it is actively listening to. Not a passively listening port.
I have not changed my system, it worked for months fine, they pushed a new update on me, and it quit working. I was hoping I could work around it, but they have slammed the door in my face with, “we do not support linux”. They will not help in any way. I guess I could get some hack tools to portscan myself, but if memory serves, that shows “open” ports for something that it is actively listening to. Not a passively listening port.
Out of interest, what is the software you are referring to?
Don’t laugh. World of tanks. One of the side benefits of getting this to work was learning about Playonlinux. What a great little wrapper! Google quit supporting Picasa for Linux awhile back and I found out by accident that I can use Playonlinux to install Picasa through it. Works better than ever!
So now I’m stuck playing WOT on a mac laptop. Ironically the playonmac wrapper works. ??
Thanks. I actually DID post in the playonlinux site, but nothing in 2 weeks. I guess I should troll back there and see if it has even been read. I didn’t think of Steam, but I don’t think that is one of their interests, since it is a “free” game.
On 2014-05-15 22:56, lshantz wrote:
>
> deano_ferrari;2643480 Wrote:
>> You might try casting your net wider by posting in the Steam and/or
>> PlayOnLinux forums…
>
> Thanks. I actually DID post in the playonlinux site, but nothing in 2
> weeks. I guess I should troll back there and see if it has even been
> read. I didn’t think of Steam, but I don’t think that is one of
> their interests, since it is a “free” game.
There is also a game subforum here, at opensuse forums. I see a post on
2013 about that game - yes, it is an old post, but I can only search
subject lines easily, not contents. There may be more.
One of the side benefits of getting this to work was learning about Playonlinux. What a great little wrapper! Google quit supporting Picasa for Linux awhile back and I found out by accident that I can use Playonlinux to install Picasa through it. Works better than ever!
I didn’t think of Steam, but I don’t think that is one of their interests, since it is a “free” game.
I didn’t think of Steam, but I don’t think that is one of