Given an IP address, how can I prevent any connection both to and from that IP? If there are multiple methods, please describe the pros and cons of each.
I've found a lot of contradictory and confusing information about this online and in the documentation.
Thanks for any help!
many people using Fedora/CentOS/RHEL/.. for organizing gateways, with
transparent proxy or with many other options. And they using iptables.
I have not seen any examples for organizing gateway with/without
transparent proxy using firewalld.
I think would be good if we will have this how-to.
P.S. I can't write this doc, because I can't set it up =(
The most visible change is a new feature, which allows you to
save active runtime configuration and overwrite permanent configuration
The way this is supposed to work is that when configuring firewalld you
do runtime changes only and
once you're happy with the configuration and you tested that it works
the way you want, you save
the configuration to disk.
You do that by running:
$ firewall-cmd --runtime-to-permanent
or selecting 'Runtime To Permanent' in firewall-config menu.
(while I'm writing this I've noticed that it's not documented in
firewall-cmd man page and
also the firewall-config says 'permant' instead of 'permanent' - but
that needs to wait for another release)
Second most significant change (even not visible to end users)
is that D-Bus interfaces for permanent changes are now
more fine grained and there are new methods for permanent
changes of zones, services, icmptypes, direct and policies (lockdown
so the permanent interfaces are more in sync with runtime ones.
- richLanguage: allow using destination with forward-port
- Rich_Rule.check(): action can't be used with
- fixed Python specific D-Bus exception (RHBZ#1132441)
- use new D-Bus methods for permanent changes
- show target REJECT instead of %%REJECT%% (RHBZ#1058794)
- --direct: make fail messages consistent (RHBZ#1141835)
- richRuleDialog - OK button tooltip indicates problem
- use new D-Bus methods for permanent changes
- show target REJECT instead of %%REJECT%% (RHBZ#1058794)
- update "Change Zones of Connections" menu on default zone change
- fixed rename of zones, services and icmptypes to not create new
- new service for Squid HTTP proxy server
- new service for Kerberos admin server
- new services for syslog and syslog-tls
- new services for SNMP and SNMP traps
- add Keywords to .desktop to improve software searchability
- updated translations
- firewalld.richlanguage: improvements suggested by Rufe Glick
- firewalld.dbus: various improvements
- firewalld.zone: better description of Limit tag
- mention new homepage everywhere
So under iptables I am able to do things like:
-A PREROUTING -d 22.214.171.124 -j DNAT --to-destination 10.2.1.1
-A POSTROUTING -s 10.2.1.1 -j SNAT --to-source 126.96.36.199
-A PREROUTING -d 188.8.131.52 -p tcp -m tcp --dport 80 -j DNAT --to-destination 10.3.1.1
-A PREROUTING -d 184.108.40.206 -p tcp -m tcp --dport 443 -j DNAT --to-destination 10.3.1.1
-A PREROUTING -d 220.127.116.11 -p tcp -m tcp --dport 25 -j DNAT --to-destination 10.4.1.1
-A PREROUTING -d 18.104.22.168 -p tcp -m tcp --dport 110 -j DNAT --to-destination 10.4.1.1
-A POSTROUTING -s 10.0.0.0/8 ! -d 10.0.0.0/8 -j MASQUERADE
I am at a loss to figure out how to do that under firewalld.
The main intention here is to have a particular incoming addr[:port] be redirected to a particular internal addr[:port] used to have VMs on an internal network (10.x.y.z).
The net effect of the above entry is a specific external IP address appears to be a specific internal server, even for outgoing connections while the other internal servers get masqueraded as the primary ip.
The piece I cannot seem to find is to tell firewalld-cmd to use a particular destination ip address for incoming requests and NAT that.
I have tried:
firewall-cmd --zone=public --remove-rich-rule='rule family="ipv4" destination address="22.214.171.124" forward-port to-addr="10.3.1.2" protocol="tcp" port="0-65535"'
But that seems to ignore the destination address and instead routes everything for ALL addresses to 10.3.1.2
Is there a way with firewall-cmd to only nat traffic coming in to for a particular IP address when there are several IP addresses on the same nic?
Naval Postgraduate School
we develop security guidance / compliance related tools and content
for Red Hat Enterprise Linux. Recently within the effort to port old(er)
iptables sections from Red Hat Enterprise Linux 6 to Red Hat Enterprise
Linux 7 we encountered the following firewalld related question.
Please have a look at sample guidance document at:
In the section "2.5.7. iptables and ip6tables", under rule:
"126.96.36.199.a. Set Default iptables Policy for Incoming Packets" there's
the following requirement:
To set the default policy to DROP (instead of ACCEPT) for the
built-in INPUT chain which processes incoming packets, add or
correct the following line in /etc/sysconfig/iptables:
:INPUT DROP [0:0]
The question is how to ensure the iptables rule of the exact meaning
is applied on the system by using firewalld related tools? In other
words is there a way via firewalld tools how to change default policy
type from "ACCEPT" to e.g. "DROP" for some particular filter chain
(e.g. "INPUT")? [*]
Thank you && Regards, Jan.
Jan iankko Lieskovsky / Red Hat Security Technologies Team
[*] We are aware that firewalld uses different configuration file
than /etc/sysconfig/iptables & can handle that. But the question
is how to change the default policy type from 'ACCEPT' to something
I didn't know that /etc/firewalld/direct.xml file exists. And I didn't know that rules added through the direct interface can be made permanent.
The thing is that I'm preparing for the RHCE (RHEL 7) exam. And there aren't any study guides out there for this version yet. So the first place I go for information is the official Red Hat documentation for RHEL 7 [https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/].
Here [https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/...] in the second paragraph of the 'Understandin the Direct Interface' section of the 'Security Guide'. It says that 'The direct interface mode is intended for services or applications to add specific firewall rules during run time. The rules are not permanent and need to be applied every time after receiving the start, restart or reload message from firewalld using D-BUS.'
Then later in the same document [https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/...] the note under the 'Configuring the Firewall Using the Command Line Tool, firewall-cmd' says that 'In order to make a command permanent or persistent, add the --permanent option to all commands apart from the --direct commands (which are by their nature temporary).'
Now I see that those statements are either outdated or simply incorrect. I'll take a closer look on the direct interface. Thanks for pointing it out for me. I think that is what I need for limiting outgoing traffic.
On 10/13/2014 7:25:50 AM, Jiri Popelka <jpopelka(a)redhat.com> wrote:
On 10/06/2014 07:41 PM, Rufe Glick wrote:
> While skimming through this mailing list's archives I saw that this
> question was raised a couple of times. And last time in August of this
> year Jiri reiterated that "So far we don't handle outbound traffic in
> So if I still need to limit outgoing traffic what is the best way to
> proceed? I could probably use the direct interface. But then I'll have
> to write a daemon that'll handle reload\reboot events of firewalld to
> re-add the rules. That sounds a bit complicated.
Have you known that 'direct' configuration can be stored in
see firewalld.direct man page.
Or you can use firewall-cmd like for example:
$ firewall-cmd --permanent --direct --add-rule ipv4 filter OUTPUT 0 -p
tcp -m tcp --sport 1234 -j DROP
Or perhaps I don't understand your use case.
> The only solution I see is to disable the firewalld service altogether
> and fall back to iptables service.
> Any other ideas?
> Also in my opinion a full value firewall solution has to have an
> ability to limit outgoing traffic. Are there plans to incorporate this
> functionality any time soon?
None that I know of.
While skimming through this mailing list's archives I saw that this
question was raised a couple of times. And last time in August of this
year Jiri reiterated that "So far we don't handle outbound traffic in
So if I still need to limit outgoing traffic what is the best way to
proceed? I could probably use the direct interface. But then I'll have
to write a daemon that'll handle reload\reboot events of firewalld to
re-add the rules. That sounds a bit complicated.
The only solution I see is to disable the firewalld service altogether
and fall back to iptables service.
Any other ideas?
Also in my opinion a full value firewall solution has to have an
ability to limit outgoing traffic. Are there plans to incorporate this
functionality any time soon?
> >> 2. In the *Action *description the very last line says "Also an action
> >> can be limited using the /limit tag/." What limit tag does the statement
> >> refer to?
> > The limit tag is described in Log.
> The thing is that 'limit tag' term is not used in the description of
> the Log element. Please use the 'limit tag' term in the description of
> the Log element at least once. For consistency it'll also be a good
> idea to include that extra option in the description of the Action
> element, like this:
> accept | reject [type="reject type"] | drop [limit value="rate/duration"]
> For me this rises another question. What does it mean to limit, say,
> an accept action to once a day? Does it mean that only one connection
> attempt a day will be let through the firewall and all other attempts
> be dropped? Will they be dropped with a drop action? How about reject
> action (if once a day) -- will the first connection attempt be
> rejected with ICMP message and all other attempts be dropped? And for
> the drop action rate limiting will not change anything then. Please
Well, after some tests I see that what I suggested is not true. The 'limit
tag' doesn't limit connection attempts. So what exactly does the limit tag
do for the action? Please consider the following example and explain me the
firewall-cmd --add-rich-rule='rule family=ipv4 service name=http accept
firewall-cmd --add-rich-rule='rule family=ipv4 service name=http accept'
Please clarify the following issues related to the rich language for me:
1. In the Rule description it is said that "If source or destination addresses are used in a rule, then the rule family need to be provided." Then in the description for the Source says that "A source address or address range is either an IP address or a network IP address with a mask for IPv4 or IPv6. The network family (IPv4/IPv6) will be automatically discovered)."
It seems to me that wordings marked in italic contradict each other. When using source keyword the rule family either has to be provided or it will be discovered automatically. Which one is true?
2. In the Action description the very last line says "Also an action can be limited using the limit tag." What limit tag does the statement refer to?
System info: CentOS 7, firewalld-0.3.9-7.el7.noarch
On the 'forwarder' machine with ip address of 10.0.0.1 I set up port forwarding using firewalld from of5001-5002/tcp range to ports 6001-6002 of 10.0.0.2 machine. Now when I connect to 10.0.0.1 from a third machine to ports 5001 or 5002 both connections go to port 6001 of the 10.0.0.2 machine; no connection ever goes to port 6002. So what's the purpose of having range if connections to all 'forward-from-ports' always go to the first port from the 'forward-to-ports' range? What am I missing?