[CentOS] DNS or firewall problem

Tue Jul 6 22:50:44 UTC 2010
Thomas Dukes <tdukes at sc.rr.com>

 

> -----Original Message-----
> From: centos-bounces at centos.org 
> [mailto:centos-bounces at centos.org] On Behalf Of Chan Chung 
> Hang Christopher
> Sent: Tuesday, July 06, 2010 9:28 AM
> To: centos at centos.org
> Subject: Re: [CentOS] DNS or firewall problem
> 
> 
> >> Are you running a proxy for http? It would be rather 
> surprising that 
> >> internal machines can access the Internet without 
> forwarding turned 
> >> on otherwise. When you say internal machines cannot access your 
> >> server, are they connecting to it via the local 
> interface's ip or the 
> >> Internet ip?
> >> Are the services bound to the local interface?
> > 
> > 
> > I did notice today there is a squid.conf file in my 
> /etc/httpd/conf.d 
> > directory. It appears it is configure for the local domain only.  I 
> > renamed it and restarted apache but that didn't work.
> > 
> > The server has two nics, one for internet and one for the local 
> > network, connected to a switch. eth0 is connected to the 
> uplink port.
> 
> Please pastebin the output of the following:
> Run as root:
> 'cat /etc/sysconfig/iptables'

# Firewall configuration written by system-config-securitylevel
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp --icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p 50 -j ACCEPT
-A RH-Firewall-1-INPUT -p 51 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp --dport 5353 -d 224.0.0.251 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 21 -j
ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 25 -j
ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m udp -p udp --dport 137 -j
ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m udp -p udp --dport 138 -j
ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 139 -j
ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 445 -j
ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 443 -j
ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j
ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT


> 'netstat -ntlp'

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address
State       PID/Program name   
tcp        0      0 0.0.0.0:20000               0.0.0.0:*
LISTEN      3580/perl           
tcp        0      0 127.0.0.1:2208              0.0.0.0:*
LISTEN      2960/hpiod          
tcp        0      0 0.0.0.0:3306                0.0.0.0:*
LISTEN      3138/mysqld         
tcp        0      0 127.0.0.1:3310              0.0.0.0:*
LISTEN      3049/clamd          
tcp        0      0 0.0.0.0:111                 0.0.0.0:*
LISTEN      2667/portmap        
tcp        0      0 0.0.0.0:6000                0.0.0.0:*
LISTEN      3958/X              
tcp        0      0 0.0.0.0:10000               0.0.0.0:*
LISTEN      3588/perl           
tcp        0      0 192.168.1.101:53            0.0.0.0:*
LISTEN      2639/named          
tcp        0      0 127.0.0.1:53                0.0.0.0:*
LISTEN      2639/named          
tcp        0      0 127.0.0.1:631               0.0.0.0:*
LISTEN      2980/cupsd          
tcp        0      0 0.0.0.0:25                  0.0.0.0:*
LISTEN      3218/sendmail: acce 
tcp        0      0 127.0.0.1:953               0.0.0.0:*
LISTEN      2639/named          
tcp        0      0 0.0.0.0:766                 0.0.0.0:*
LISTEN      2704/rpc.statd      
tcp        0      0 0.0.0.0:3551                0.0.0.0:*
LISTEN      3032/apcupsd        
tcp        0      0 127.0.0.1:2207              0.0.0.0:*
LISTEN      2965/python         
tcp        0      0 :::80                       :::*
LISTEN      5464/httpd          
tcp        0      0 :::6000                     :::*
LISTEN      3958/X              
tcp        0      0 ::1:953                     :::*
LISTEN      2639/named          
tcp        0      0 :::443                      :::*
LISTEN      5464/httpd         

Not sure what all this means. Hope someone can.

Thanks!!

Eddie
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