Hi ,
How Do I enable a port 843 in a Linux machine . I have written a server program that listens to port 843 and responds when requested . But Client socket request is not able to reach that port . socket.connect functions returns -1 with timeout . I have edited /etc/services to add that port . But this is not working . Please help me out . Thanks in advance .

regards
Suman

Hi Suman,

What distribution are you using? I suspect this answer will lay in a firewall and as the most common firewalling tool in linux tends to be iptables (that interacts with the kernel routing tables). Try the following two commands.

/etc/init.d/iptables status
iptables -nvL

If the two commands give the same output then copy and paste one set of results here and we should be able to better guide you what modifications. If iptables status says that iptables is on or active then copy and paste the results of "iptables -nvL" here.

Thanks for the reply . I am using ("MontaVista 3.4.3-25.0.143.0800417 2008-02-22" distribution . Though I could not execute "/etc/init.d/iptables status" , I have executed "iptables -nvL" . It gives the following output .

Chain INPUT (policy DROP 8828 packets, 834K bytes)
pkts bytes target prot opt in out source destination
0 0 DROP all -- eth0 * 0.0.0.0/0 127.0.0.0/8
415K 42M ACCEPT all -- * * 0.0.0.0/0 127.0.0.0/8
0 0 ACCEPT all -- vlan4042 * 0.0.0.0/0 0.0.0.0/0
0 0 ACCEPT all -- vlan4043 * 0.0.0.0/0 0.0.0.0/0
163K 19M ACCEPT all -- vlan4044 * 0.0.0.0/0 0.0.0.0/0
44 17408 ACCEPT all -- vlan4047 * 0.0.0.0/0 0.0.0.0/0
0 0 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0
15320 968K samrules all -- * * 0.0.0.0/0 10.65.124.26

Chain FORWARD (policy DROP 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * * 127.0.0.0/8 0.0.0.0/0

Chain OUTPUT (policy ACCEPT 552K packets, 214M bytes)
pkts bytes target prot opt in out source destination
0 0 DROP all -- * eth0 127.0.0.0/8 0.0.0.0/0

Chain samrules (1 references)
pkts bytes target prot opt in out source destination
15 820 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:443
12675 722K ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80
2407 202K ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22
0 0 DROP tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:514
11 832 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0
0 0 ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
116 37587 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED

If this server is sitting on the 10.65.124.26 ip, then I believe the solution to this on is the following.

iptables -I samrules -p tcp --dport 843 -j ACCEPT

however I don't know much about the service, if it instead uses udp then the following would be the more correct line

iptables -I samrules -p udp --dport 843 -j ACCEPT

Please note this line is not a perm fix and will be lost on the next restart of iptables, the service is likely stored in /etc/init.d/ but under a different name, like firewall. I do not know the iptables save method preferred by the distribution you are using either.

Thanks . It works . I appreciate your help .

If this works and you are satisfied with it, could you go to the thread tools and click the "mark this thread as solved" link.

As I would point out however, this rule is only temporary and will be lost on an iptables restart (you can easily re-apply this but this manual method has a few drawbacks), so you may want to look into that yourself. However if you need further help here, feel free to ask for it and do not mark this thread as solved yet.

R3sistance

Hi ,
My problem is solved temporarily . But I am investigating for a permanent solution as you suggested . Lets keep the thread open .

regards
Suman