1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
Firewall
========
VyOS makes use of Linux [http://netfilter.org/ netfilter] for packet filtering.
The firewall supports the creation of groups for ports, addresses, and networks
(implemented using netfilter ipset) and the option of interface or zone based
firewall policy.
**Important note on usage of terms:** The firewall makes use of the terms
`in`, `out`, and `local` for firewall policy. Users experienced with netfilter
often confuse `in` to be a reference to the `INPUT` chain, and `out` the
`OUTPUT` chain from netfilter. This is not the case. These instead indicate the
use of the `FORWARD` chain and either the input or output interface. The
`INPUT` chain, which is used for local traffic to the OS, is a reference to
as `local` with respect to its input interface.
Zone-based Firewall Policy
--------------------------
As an alternative to applying policy to an interface directly, a zone-based
firewall can be created to simplify configuration when multiple interfaces
belong to the same security zone. Instead of applying to rulesets to interfaces
they are applied to source zone-destination zone pairs.
An introduction to zone-based firewalls can be found [[A primer to Zone Based
Firewall|here]]. For an example see [[Zone-policy_example|Zone-policy example]].
Groups
------
Firewall groups represent collections of IP addresses, networks, or ports. Once
created, a group can be referenced by firewall rules as either a source or
destination. Members can be added or removed from a group without changes to
or the need to reload individual firewall rules. Note that groups can also
be referenced by NAT configuration.
While network groups accept IP networks in CIDR notation, specific IP addresses
can be added as a 32-bit prefix. If you foresee the need to add a mix of
addresses and networks, the network group is recommended.
Here is an example of a network group for the IP networks that make up the
internal network:
.. code-block:: sh
set firewall group network-group NET-INSIDE network 192.168.0.0/24
set firewall group network-group NET-INSIDE network 192.168.1.0/24
A port group represents only port numbers, not the protocol. Port groups can
be referenced for either TCP or UDP. It is recommended that TCP and UDP groups
are created separately to avoid accidentally filtering unnecessary ports.
Ranges of ports can be specified by using `-`.
Here is an example of a port group a server:
.. code-block:: sh
set firewall group port-group PORT-TCP-SERVER1 port 80
set firewall group port-group PORT-TCP-SERVER1 port 443
set firewall group port-group PORT-TCP-SERVER1 port 5000-5010
Rule-Sets
---------
A rule-set is a named collection of firewall rules that can be applied to an
interface or zone. Each rule is numbered, has an action to apply if the rule
is matched, and the ability to specify the criteria to match.
Example of a rule-set to filter traffic to the internal network:
.. code-block:: sh
set firewall name INSIDE-OUT default-action drop
set firewall name INSIDE-OUT rule 1010 action accept
set firewall name INSIDE-OUT rule 1010 state established enable
set firewall name INSIDE-OUT rule 1010 state related enable
set firewall name INSIDE-OUT rule 1020 action drop
set firewall name INSIDE-OUT rule 1020 state invalid enable
Applying a Rule-Set to an Interface
-----------------------------------
Once a rule-set is created, it can be applied to an interface. Note only one
rule-set can be applied to each interface for `in`, `out`, or `local` traffic
for each protocol (IPv4 and IPv6).
.. code-block:: sh
set interfaces ethernet eth1 firewall out name INSIDE-OUT
Applying a Rule-Set to a Zone
-----------------------------
A named rule-set can also be applied to a zone relationship (note, zones must
first be created):
.. code-block:: sh
set zone-policy zone INSIDE from OUTSIDE firewall name INSIDE-OUT
Example Partial Config
----------------------
.. code-block:: sh
firewall {
all-ping enable
broadcast-ping disable
config-trap disable
group {
network-group BAD-NETWORKS {
network 1.2.3.0/24
network 1.2.4.0/24
}
network-group GOOD-NETWORKS {
network 4.5.6.0/24
network 4.5.7.0/24
}
port-group BAD-PORTS {
port 65535
}
}
name FROM-INTERNET {
default-action accept
description "From the Internet"
rule 10 {
action accept
description "Authorized Networks"
protocol all
source {
group {
network-group GOOD-NETWORKS
}
}
}
rule 11 {
action drop
description "Bad Networks"
protocol all
source {
group {
network-group BAD-NETWORKS
}
}
}
rule 30 {
action drop
description "BAD PORTS"
destination {
group {
port-group BAD-PORTS
}
}
log enable
protocol all
}
}
}
interfaces {
ethernet eth1 {
address dhcp
description OUTSIDE
duplex auto
firewall {
in {
name FROM-INTERNET
}
}
}
}
[https://www.xfinity.com/support/internet/list-of-blocked-ports/ XFinity Blocked Port List]
|
