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Old 05-27-2016, 01:12 PM   #1
rroopstr
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port 53 closed and port 80 open


I need port 53 open for BIND configuration, after many firewall tests I still get the following:

# firewall-cmd --zone=public --list-all
public (default)
interfaces:
sources:
services: dhcpv6-client dns http https smtp ssh
ports: 53/tcp 443/tcp 80/tcp 25/tcp 53/udp
masquerade: no
forward-ports:
icmp-blocks:
rich rules:

# nmap -p 53 5.226.169.119
Starting Nmap 6.40 ( http://nmap.org ) at 2016-05-27 13:50 BOT
Nmap scan report for mlp.riverocooper.com (5.226.169.119)
Host is up (0.000057s latency).
PORT STATE SERVICE
53/tcp closed domain

# nmap -p 80 5.226.169.119
Starting Nmap 6.40 ( http://nmap.org ) at 2016-05-27 13:50 BOT
Nmap scan report for mlp.riverocooper.com (5.226.169.119)
Host is up (0.000058s latency).
PORT STATE SERVICE
80/tcp open http

# systemctl status firewalld
* firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2016-05-27 13:46:15 BOT; 12min ago
Main PID: 3263 (firewalld)
CGroup: /system.slice/firewalld.service
`-3263 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid

May 27 13:46:14 mlp systemd[1]: Starting firewalld - dynamic firewall daemon...
May 27 13:46:15 mlp systemd[1]: Started firewalld - dynamic firewall daemon.
May 27 13:46:15 mlp firewalld[3263]: 2016-05-27 13:46:15 ERROR: ebtables not usable, disabling ethernet bridge firewall.

Last edited by rroopstr; 05-27-2016 at 01:16 PM.
 
Old 05-27-2016, 02:49 PM   #2
rroopstr
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# /usr/sbin/firewalld --nofork --nopid --debug 10
2016-05-27 15:07:42 DEBUG2: firewall.core.ebtables.ebtables: /sbin/ebtables -t filter -L
2016-05-27 15:07:42 DEBUG1: ebtables table 'filter' does not exist.
2016-05-27 15:07:42 DEBUG2: firewall.core.ebtables.ebtables: /sbin/ebtables -t broute -L
2016-05-27 15:07:42 DEBUG1: ebtables table 'broute' does not exist.
2016-05-27 15:07:42 DEBUG2: firewall.core.ebtables.ebtables: /sbin/ebtables -t nat -L
2016-05-27 15:07:42 DEBUG1: ebtables table 'nat' does not exist.

[root@mlp sbin]# /usr/sbin/ebtables -t filter -L
The kernel doesn't support the ebtables 'filter' table.
[root@mlp sbin]# /usr/sbin/ebtables -t broute -L
The kernel doesn't support the ebtables 'broute' table.
[root@mlp sbin]# /usr/sbin/ebtables -t nat -L
The kernel doesn't support the ebtables 'nat' table.
 
Old 05-27-2016, 08:59 PM   #3
Tim Abracadabra
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Maybe this helps,

https://www.certdepot.net/rhel7-get-started-firewalld/
Look partway down from the top under Port Management.
 
Old 05-27-2016, 09:02 PM   #4
rroopstr
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thanks, I'll go over it after I fix a Bug courtesy from a Red Hat employee at Fedora forum. This was the reason:

https://bugzilla.redhat.com/show_bug.cgi?id=1290327
 
Old 05-27-2016, 09:20 PM   #5
Tim Abracadabra
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Per your posted link: https://bugzilla.redhat.com/show_bug.cgi?id=1290327

How is a firewalld startup issue due to a lockfile, related to configuring an open port for DNS?
Trying to understand. Am I missing something ?

Last edited by Tim Abracadabra; 05-27-2016 at 09:39 PM. Reason: Add OP reference link
 
Old 05-27-2016, 09:43 PM   #6
rroopstr
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I would like to find out. It seems the case. The bug I showed you was similar to mine and didn't work out. By the way, the situation was the opposite a while ago: Port 53 was open and port 80 was closed. Now 53 is closed and 80 is open. Very strange. I'll try to open them both again with the standard instructions.

]# firewall-cmd --get-active-zones
NO OUTPUT. PUBLIC HASN'T BEEN ACTIVE SINCE YESTERDAY NO MATTER WHAT I DO

Regarding your question on this weird relationship, here I quote the Red Hat Employee who dealt with this before (it's on the link):
Quote:
Thomas Woerner 2015-12-18 08:24:49 EST
A lock file location of /var/lib is not optimal as it is not cleaned up automatically on reboot.

iptables is using a better lock file location: /run/xtables.lock
Additionally it is using flock on the file for locking.

For now I have added a patch to firewalld upstream (https://github.com/t-woerner/firewal...da68eff7747a81) to remove the ebtables lock file /var/lib/ebtables/lock if the lock exists but ebtables is not running. This is only a sub optional work a round and not a good solution, as it will only fix the use of ebtables in firewalld, but not in other consumers like libvirt for example. Also this patch is not applied to firewalld packages in Fedora yet.

Last edited by rroopstr; 05-27-2016 at 10:12 PM.
 
Old 05-27-2016, 10:11 PM   #7
rroopstr
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and here is output that shows you how an interface becomes disabled, so that a port (not all of them very weird) is closed
Quote:
# systemctl status firewalld
* firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2016-05-27 22:12:26 BOT; 35min ago
Main PID: 119 (firewalld)
CGroup: /system.slice/firewalld.service
`-119 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid

May 27 22:12:25 mlp systemd[1]: Starting firewalld - dynamic firewall daemon...
May 27 22:12:26 mlp systemd[1]: Started firewalld - dynamic firewall daemon.
May 27 22:12:26 mlp firewalld[119]: 2016-05-27 22:12:26 ERROR: ebtables not usable, disabling ethernet bridge firewall.
May 27 22:30:33 mlp systemd[1]: Started firewalld - dynamic firewall daemon.
 
Old 05-28-2016, 01:05 AM   #8
Tim Abracadabra
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Hmm, It seems to me your nameservers are working with some casual tests.
What does dig tell you?
 
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Old 05-28-2016, 01:12 AM   #9
rroopstr
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Everything is working now! Perhaps propagation wasn't fully completed and messed with the ports. 53 and 80 are open, my three websites are up!
Now I'm trying to open ports 25 and 587 but it seems that the ISP closes them as a policy. Which SMTP port should I use?
 
Old 05-28-2016, 04:16 AM   #10
unSpawn
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Quote:
Originally Posted by rroopstr View Post
Everything is working now!
Please note that is not the type of technical answer most of us can do much with. Next time consider posting how you tested the situation to be resloved and posting tool (if any) output.


Quote:
Originally Posted by rroopstr View Post
Now I'm trying to open ports 25 and 587 but it seems that the ISP closes them as a policy. Which SMTP port should I use?
The problem with closing RFC standard / IANA-defined protocol default ports is that there is no way for remote MTAs to know which other port they c|should access. If you expect things to work nonetheless your choices are to set up a mail forwarder (or move MTA service) elsewhere where TCP/25/587 is not blocked and update your MX records accordingly.

*BTW I'm not seeing how this is a Linux Security thread so I'm moving this to the Linux Networking forum.
 
Old 05-28-2016, 06:17 AM   #11
rroopstr
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nano /etc/sysconfig/firewalld
# firewalld command line args
# possile values: --debug
FIREWALLD_ARGS='--debug'

after having added the temporary bug solution from the Fedora link
nano /var/log/firewalld
2016-05-27 22:13:19 DEBUG1: config.ZoneAdded('block')
2016-05-27 22:13:19 DEBUG1: config.ZoneAdded('dmz')
2016-05-27 22:13:19 DEBUG1: config.ZoneAdded('drop')
2016-05-27 22:13:19 DEBUG1: config.ZoneAdded('external')
2016-05-27 22:13:19 DEBUG1: config.ZoneAdded('home')
2016-05-27 22:13:19 DEBUG1: config.ZoneAdded('internal')
2016-05-27 22:13:19 DEBUG1: config.ZoneAdded('public')
2016-05-27 22:13:19 DEBUG1: config.ZoneAdded('trusted')
2016-05-27 22:13:19 DEBUG1: config.ZoneAdded('work')
2016-05-28 01:21:00 DEBUG1: ipv4 table 'security' does not exist (or not enough permission to check).
2016-05-28 01:21:00 DEBUG1: ipv6 table 'raw' does not exist (or not enough permission to check).
2016-05-28 01:21:00 DEBUG1: ipv6 table 'security' does not exist (or not enough permission to check).
2016-05-28 01:21:00 DEBUG1: ipv6 table 'nat' does not exist (or not enough permission to check).
2016-05-28 01:21:00 DEBUG1: ebtables table 'filter' does not exist.
2016-05-28 01:21:00 DEBUG1: ebtables table 'broute' does not exist.
2016-05-28 01:21:00 DEBUG1: ebtables table 'nat' does not exist.
2016-05-28 01:21:00 DEBUG1: start()
2016-05-28 01:21:00 ERROR: ebtables not usable, disabling ethernet bridge firewall.
2016-05-28 01:21:00 DEBUG1: Loading firewalld config file '/etc/firewalld/firewalld.conf'
2016-05-28 01:21:00 DEBUG1: IPv6 rpfilter is enabled
2016-05-28 01:21:00 DEBUG1: Loading lockdown whitelist
2016-05-28 01:21:00 DEBUG1: Loading icmptype file '/usr/lib/firewalld/icmptypes/destination-unreachable.xml'
2016-05-28 01:21:00 DEBUG1: Loading zone file '/usr/lib/firewalld/zones/block.xml'
2016-05-28 01:21:00 DEBUG1: Loading zone file '/usr/lib/firewalld/zones/dmz.xml'
2016-05-28 01:21:00 DEBUG1: Loading zone file '/usr/lib/firewalld/zones/drop.xml'
2016-05-28 01:21:00 DEBUG1: Loading zone file '/usr/lib/firewalld/zones/external.xml'
2016-05-28 01:21:00 DEBUG1: Loading zone file '/usr/lib/firewalld/zones/home.xml'
2016-05-28 01:21:00 DEBUG1: Loading zone file '/usr/lib/firewalld/zones/internal.xml'
2016-05-28 01:21:00 DEBUG1: Loading zone file '/usr/lib/firewalld/zones/public.xml'
2016-05-28 01:21:00 DEBUG1: Loading zone file '/usr/lib/firewalld/zones/trusted.xml'
2016-05-28 01:21:00 DEBUG1: Loading zone file '/usr/lib/firewalld/zones/work.xml'
2016-05-28 01:21:00 DEBUG1: Loading zone file '/etc/firewalld/zones/home.xml'
2016-05-28 01:21:00 DEBUG1: Overloads zone 'home' ('/usr/lib/firewalld/zones/home.xml')
2016-05-28 01:21:00 DEBUG1: Loading zone file '/etc/firewalld/zones/internal.xml'
2016-05-28 01:21:00 DEBUG1: Overloads zone 'internal' ('/usr/lib/firewalld/zones/internal.xml')
2016-05-28 01:21:00 DEBUG1: Loading zone file '/etc/firewalld/zones/public.xml'
2016-05-28 01:21:00 DEBUG1: Overloads zone 'public' ('/usr/lib/firewalld/zones/public.xml')
2016-05-28 01:21:00 DEBUG1: Loading zone file '/etc/firewalld/zones/work.xml'
2016-05-28 01:21:00 DEBUG1: Overloads zone 'work' ('/usr/lib/firewalld/zones/work.xml')
2016-05-28 01:21:00 DEBUG1: Using default zone 'public'
2016-05-28 01:21:00 DEBUG1: config.ZoneAdded('work')
2016-05-28 01:22:29 DEBUG1: stop()
2016-05-28 01:22:29 Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/firewall/server/decorators.py", line 40, in handle_exceptions
return func(*args, **kwargs)
File "/usr/lib/python2.7/site-packages/firewall/server/firewalld.py", line 84, in stop
log.debug1("stop()")
File "/usr/lib/python2.7/site-packages/firewall/core/logger.py", line 275, in <lambda>
self.debug(x, message, *args, **kwargs))(self, _level))
File "/usr/lib/python2.7/site-packages/firewall/core/logger.py", line 438, in debug
self._log(level, format, *args, **kwargs)
File "/usr/lib/python2.7/site-packages/firewall/core/logger.py", line 683, in _log
target.write(_format % dict, level, self, is_debug)
File "/usr/lib/python2.7/site-packages/firewall/core/logger.py", line 62, in write
self.flush()
File "/usr/lib/python2.7/site-packages/firewall/core/logger.py", line 68, in flush
self.fd.flush()
IOError: [Errno 5] Input/output error

2016-05-28 01:22:29 DEBUG1: reload()
2016-05-28 01:22:29 DEBUG1: Loading firewalld config file '/etc/firewalld/firewalld.conf'
2
2016-05-28 01:22:30 DEBUG1: Reloaded()
2016-05-28 01:24:15 DEBUG1: zone.getActiveZones()
2016-05-28 01:25:21 DEBUG1: zone.getZones()
2016-05-28 01:25:44 DEBUG1: zone.getZoneOfInterface('venet0')
2016-05-28 01:26:46 DEBUG1: getDefaultZone()
2016-05-28 01:26:46 DEBUG1: zone.getActiveZones()
2016-05-28 01:26:46 DEBUG1: zone.getServices('')
2016-05-28 01:27:05 DEBUG1: zone.getPorts('internal')
2016-05-28 01:27:15 DEBUG1: getDefaultZone()
2016-05-28 01:27:15 DEBUG1: zone.getActiveZones()
2016-05-28 01:27:15 DEBUG1: zone.getPorts('')
2016-05-28 01:28:29 DEBUG1: zone.getActiveZones()
2016-05-28 01:29:11 DEBUG1: getDefaultZone()
2016-05-28 01:29:11 DEBUG1: zone.getActiveZones()
2016-05-28 01:29:11 DEBUG1: zone.addInterface('', 'lo')
2016-05-28 01:29:11 DEBUG1: zone.InterfaceAdded('public', 'lo')
2016-05-28 01:29:16 DEBUG1: getDefaultZone()
2016-05-28 01:29:16 DEBUG1: zone.getActiveZones()
2016-05-28 01:29:16 DEBUG1: zone.addInterface('', 'venet0')
2016-05-28 01:29:16 DEBUG1: zone.InterfaceAdded('public', 'venet0')
2016-05-28 01:29:19 DEBUG1: getDefaultZone()
2016-05-28 01:29:19 DEBUG1: zone.getActiveZones()
2016-05-28 01:29:19 DEBUG1: zone.addInterface('', 'venet0:0')
2016-05-28 01:29:19 DEBUG1: zone.InterfaceAdded('public', 'venet0:0')
2016-05-28 01:29:46 DEBUG1: getDefaultZone()
2016-05-28 01:29:46 DEBUG1: zone.getActiveZones()
2016-05-28 01:29:46 DEBUG1: zone.queryInterface('', 'lo')
2016-05-28 01:29:52 DEBUG1: getDefaultZone()
2016-05-28 01:29:52 DEBUG1: zone.getActiveZones()
2016-05-28 01:29:52 DEBUG1: zone.queryInterface('', 'venet0')
2016-05-28 01:29:55 DEBUG1: getDefaultZone()
2016-05-28 01:29:55 DEBUG1: zone.getActiveZones()
2016-05-28 01:29:55 DEBUG1: zone.queryInterface('', 'venet0:0')
2016-05-28 01:30:12 DEBUG1: zone.getActiveZones()
2016-05-28 01:30:51 DEBUG1: getDefaultZone()
2016-05-28 01:30:51 DEBUG1: zone.getActiveZones()
2016-05-28 01:30:51 DEBUG1: zone.getServices('')
2016-05-28 01:32:06 DEBUG1: getDefaultZone()
2016-05-28 01:32:06 DEBUG1: zone.getActiveZones()
2016-05-28 01:32:06 DEBUG1: zone.queryPort('', '587', 'tcp')
2016-05-28 01:32:12 DEBUG1: getDefaultZone()
2016-05-28 01:32:12 DEBUG1: zone.getActiveZones()
2016-05-28 01:32:12 DEBUG1: zone.queryPort('', '587', 'udp')
2016-05-28 01:33:01 DEBUG1: config.listServices()

which means that after reloading firewalld I must enable interfaces manually until another release of the software becomes available
 
Old 05-28-2016, 09:47 AM   #12
rroopstr
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Quote:
Originally Posted by unSpawn View Post
*BTW I'm not seeing how this is a Linux Security thread so I'm moving this to the Linux Networking forum.
I posted it under security because the command I am learning to use is firewalld which besides security also refers to networking. I am sure this may be one reason why so many people are confused transitionaing from iptables to firewalld
 
Old 05-28-2016, 11:02 AM   #13
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Quote:
Originally Posted by rroopstr View Post
I posted it under security because the command I am learning to use is firewalld which besides security also refers to networking. I am sure this may be one reason why so many people are confused transitionaing from iptables to firewalld
firewalld is only a front-end for iptables, just like UFW claims to be. I've looked at it and find straight iptables much easier to work with, but maybe I've missed something. What do you see as the benefit for firewalld? Where is the value-added over plain iptables?
 
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Old 05-28-2016, 11:16 AM   #14
rroopstr
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Quote:
Originally Posted by Turbocapitalist View Post
firewalld is only a front-end for iptables, just like UFW claims to be. I've looked at it and find straight iptables much easier to work with, but maybe I've missed something. What do you see as the benefit for firewalld? Where is the value-added over plain iptables?
I have no idea. I have been using linux for only one month. Earlier this morning I accidentally deleted /var/lib so I had to reinstall CentOs 7 again. In just a couple of hours I reconfigured firewalld and named. I am about to reconfigure apache as soon as my sites finish sftp uploading from my windows machine. However right now ports 22, 53 and 80 are open. I was lucky that propoagation also works reverse, all servers learned my domains an ip addresses, didn't flush their tables, and temporarily the Apache welcome page shows in all my sites until I reconfigure virtual hosts in the next few minutes.

Basically I just learned how to use firewalld and wouldn't feel like learning iptables from scratch.

I don't know if this thread may be retitled, but would like to divert attention toward ports 53 and 587. I am unable to open them. Will open automatically as soon as I configure postfix? My VPS provider says that they do not block any ports whatsoever and that I am free to configure my VPS any way I want.

Thanks to everyone for your big help. This forum has guided my learning during the last few weeks. I thought this morning that I would collapse after having erased var/lib and it's only noon and am about finished... with the bonus that there is a lot of junk I previously downloaded as duplicate and won't download again, which was the original cause for the issues explained earlier in this thread.
 
Old 05-28-2016, 03:09 PM   #15
/dev/random
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Easy to fix (sometimes new isn’t always better):
yum remove firewalld

Code:
iptables -P INPUT DROP

# Allow local loopback
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT

# Allow DNS
iptables -A INPUT -i eth0 -p tcp --sports 53 -m state --state ESTABLISHED -j ACCEPT
iptables -A INPUT -i eth0 -p udp --sports 53 -m state --state ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o eth0 -p tcp --dports 53 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o eth0 -p udp --dports 53 -m state --state NEW,ESTABLISHED -j ACCEPT

# Allow HTTP(S)
iptables -A INPUT -i eth0 -p tcp --sport 80 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --sport 443 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o eth0 -p tcp --dport 80 -m state --state ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o eth0 -p tcp --dport 443 -m state --state ESTABLISHED -j ACCEPT

# Allow SSH
iptables -A INPUT -i eth0 -p tcp --sport 22 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o eth0 -p tcp --dport 22 -m state --state ESTABLISHED -j ACCEPT

Last edited by /dev/random; 05-28-2016 at 03:21 PM. Reason: Add SSH tothe rules.
 
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