LinuxQuestions.org - port 86 blocked on SYN

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port 86 blocked on SYN_SENT

Hi all.

I have a strange problem, I can't reach remote port 86 from my system.

I have installed an IP webcam which has a bultin http server. This webcam is set to hear on port 86.

If I open in a browser <ip>:86 I should get the login window, but I don't receive nothing at all, until I get a timout.

The camera is an Intellinet ( http://www.intellinet-network.com/ipcamera/550710.php )

The webcam works perfectly, accessing from windows and or linux (distro different from slack)

I'm under a NAT , but it doesn't block port 86. In fact accessing from windows to the webcam it works perfectly.

ATM accessing from another pc with windows on the same lan there's no problems, from my box (slack current) there's no way to have it working.

I was doubting that the problem was the webcam, so I tried accessing another (identical) webcam hearing on another port (82) and I have no problems with that

I tried opening the webcam from konqueror, firefox, opera, links, lynx, telnet (telnet <ip> 86) and I never get any response.

Launching a netstat while the browser try connecting I see this line:

tcp 0 1 192.168.1.6:37174 xxx.xxx.xxx.xxx.:mfcobol SYN_SENT

(mfcobol corresponds on port 86)

this line remain identical until I get a timeout in the browser.

I tried from another slackware system (this time a slack 10.1 not updated) connected directly to the internet via PPP without passing a nat and the behaviour is identical to the one I see on my pc, in every aspect.

It seems that I can't receive a reply.

I'm not a network man so I don't know how to investigate deeper to find the problem.

If someone wants to try and needs IPs of the 2 webcams simply ask, I'll send them by email (or PM)

I tried searching in every way on google and on this and other forums and I can't find a solution ....

Quote:

I'm under a NAT

Do you mean you run NAT iptables rules in your slackware system ?
Have you configured some iptables rules ?
try : /sbin/iptables -L -n
(to make sure)

the NAT is running on another machine, on my box iptables is not configurated at all ..

on the rc.firewall script on the 'router' there's none blocking rules, and absolutely no reference to port 86 or the mfcobol service

the script is minimal - the strict minimal need to works

this is the output of iptables -L -n: on my box

Code:

root@Trombino:/home/barx# iptables -L -n

Chain INPUT (policy ACCEPT)

target    prot opt source              destination



Chain FORWARD (policy ACCEPT)

target    prot opt source              destination



Chain OUTPUT (policy ACCEPT)

target    prot opt source              destination

root@Trombino:/home/barx#

so there aren't rules set ..

I think the server running iptables isn't the cause of the problem because Windows boxes under this NAT haven't problems with the webcam, and I have this problem on another box which is connected to the internet via ppp and that hasn't iptables set ...

When you say

Quote:

The webcam works perfectly, accessing from windows and or linux (distro different from slack)

You mean you rebooted the same machine in windows and
in other installed linux system on this machine ?

Yes rebooting to win and tryng from knoppix from the same machine I have no problems on port 86

Sorry for asking, but when you boot in windows, knoppix, slackware...
is it the same IP in each case ? How is it configured, with DHCP ?
There is no rules to block IPs in your webcam camera ?

I'm using statics IPs and I always use the same network config (ip netmask GW dns)

There are no rules at all in the webcam, and another friend has the same problem connecting in dialup (using dinamic ip of course)