providers - Shorewall Providers file
This file is used to define additional routing tables. You will want to define
an additional table if:
•You have connections to more than one
ISP or multiple connections to the same ISP
•You run Squid as a transparent proxy
on a host other than the firewall.
•You have other requirements for policy
Each entry in the file defines a single routing table.
If you wish to omit a column entry but want to include an entry in the next
column, use "-" for the omitted entry.
The columns in the file are as follows.
The provider name. Must be a valid
shell variable name. The names 'local', 'main', 'default' and 'unspec' are
reserved and may not be used as provider names.
The provider number -- a number between 1 and
15. Each provider must be assigned a unique value.
(Optional) - value
A FWMARK value
used in your
 file to direct packets to this provider.
If HIGH_ROUTE_MARKS=Yes in shorewall.conf(5)
, then the value must be a
multiple of 256 between 256 and 65280 or their hexadecimal equivalents (0x0100
and 0xff00 with the low-order byte of the value being zero). Otherwise, the
value must be between 1 and 255. Each provider must be assigned a unique mark
value. This column may be omitted if you don't use packet marking to direct
connections to a particular provider.
The name of an existing table to duplicate to
create this routing table. May be main or the name of a previously
listed provider. You may select only certain entries from the table to copy by
using the COPY column below. This column should contain a dash ("-') when
USE_DEFAULT_RT=Yes in shorewall.conf(5).
The name of the network interface to the
provider. Must be listed in shorewall-interfaces(5)
. In general,
that interface should not have the proxyarp
option specified unless
is given in the OPTIONS column of this entry.
Where more than one provider is serviced through a single interface, the
must be followed by a colon and the IP address
interface that is supplied by the associated provider.
The IP address of the provider's gateway
router. Beginning with Shorewall 4.6.2, you may also specify the MAC address
of the gateway when there are multiple providers serviced through the same
interface. When the MAC is not specified, Shorewall will detect the MAC during
firewall start or restart.
You can enter detect
here and Shorewall will attempt to detect the
Beginning with Shorewall 5.0.6, you may also enter none
. This causes
creation of a routing table with no default route in it.
For PPP devices, you may omit this column.
(Optional) - [-
A comma-separated list selected from the
following. The order of the options is not significant but the list may
contain no embedded white-space.
Added in Shorewall 4.5.17. Causes a host route
to the provider's gateway router to be added to the provider's routing table.
This is the default behavior unless overridden by a following noautosrc
If specified, inbound connections on this
interface are to be tracked so that responses may be routed back out this same
You want to specify track
if internet hosts will be connecting to local
servers through this provider.
Beginning with Shorewall 4.4.3, track
defaults to the setting of the
TRACK_PROVIDERS option in shorewall.conf
 (5). If you set
TRACK_PROVIDERS=Yes and want to override that setting for an individual
provider, then specify notrack
The providers that have balance
specified will get outbound traffic load-balanced among them. By default, all
interfaces with balance specified will have the same weight (1). You
can change the weight of an interface by specifying
balance=weight where weight is the weight of the route
out of this interface.
Shorewall normally adds a routing rule for
each IP address on an interface which forces traffic whose source is that IP
address to be sent using the routing table for that interface. Setting
loose prevents creation of such rules on this interface.
Added in Shorewall 4.6.0. This option provides
an alternative method of load balancing based on probabilities. Providers to
be balanced are given a probability (a number 0 > n >= 1) with up
to 8 digits to the right of the decimal point. Beginning with Shorewall
4.6.10, a warning is issued if the sum of the probabilities is not
Added in Shorewall 4.5.17. Prevents the
addition of a host route to the provider's gateway router from being added to
the provider's routing table. This option must be used with caution as it can
cause start and restart failures.
Added in Shorewall 4.4.3. When specified,
turns off track.
optional (deprecated for use with providers that do not share an
If the interface named in the INTERFACE column
is not up and configured with an IPv4 address then ignore this provider. If
not specified, the value of the optional option for the INTERFACE in
shorewall-interfaces(5) is assumed. Use of that option is preferred
to this one, unless an address is provider in the INTERFACE
Added in Shorewall 4.6.6, primary is
equivalent to balance=1 and is preferred when the remaining providers
specify fallback or tproxy.
Specifies the source address to use when
routing to this provider and none is known (the local client has bound to the
0 address). May not be specified when an address is given in the
INTERFACE column. If this option is not used, Shorewall substitutes the
primary IP address on the interface named in the INTERFACE column.
Specifies the MTU when forwarding through this
provider. If not given, the MTU of the interface named in the INTERFACE column
Indicates that a default route through the
provider should be added to the default routing table (table 253). If a
is given, a balanced route is added with the weight of this
provider equal to the specified weight
. If the option is given without
, an separate default route is added through the provider's
gateway; the route has a metric equal to the provider's NUMBER.
Prior to Shorewall 4.4.24, the option is ignored with a warning message if
USE_DEFAULT_RT=Yes in shorewall.conf.
Added in Shorewall 4.5.4. Used for supporting
the TPROXY action in shorewall-mangle(5). See
http://www.shorewall.net/Shorewall_Squid_Usage.html. When specified,
the MARK, DUPLICATE and GATEWAY columns should be empty, INTERFACE should be
set to 'lo' and tproxy should be the only OPTION. Only one
tproxy provider is allowed.
Added in Shorewall 4.5.21. This is the default
behavior that results in a host route to the defined GATEWAY being
inserted into the main routing table and into the provider's routing table.
hostroute is required for older distributions but nohostroute
(below) is appropriate for recent distributions. hostroute may
interfere with Zebra's ability to add routes on some distributions such as
Added in Shorewall 4.5.21. nohostroute
inhibits addition of a host route to the defined GATEWAY being inserted
into the main routing table and into the provider's routing table.
nohostroute is not appropriate for older distributions but is
appropriate for recent distributions. nohostroute allows Zebra's to
correctly add routes on some distributions such as Debian 7.
Added in Shorewall 5.0.2 and alters the
behavior of the disable
•The provider's routing table still
contains the apprioriate default route.
•Unless the noautosrc option is
specified, routing rules are generated to route traffic from the interfaces
address(es) out of the provider's routing table.
•Persistent routing rules in
shorewall-rtrules(5) are present.
The generated script will attempt to reenable a disabled persistent provider
during execution of the start
commands. When persistent
is not specified, only the enable
commands can reenable the provider.
A comma-separated list of other interfaces on
your firewall. Wildcards specified using an asterisk ("*") are
permitted (e.g., tun* ). Usually used only when DUPLICATE is main
copy routes through INTERFACE and through interfaces listed here. If you only
wish to copy routes through INTERFACE, enter none
in this column.
Beginning with Shorewall 4.5.17, blackhole, unreachable and prohibit routes are
no longer copied by default but may be copied by including
respectively in the
You run squid in your DMZ on IP address
192.168.2.99. Your DMZ interface is eth2
#NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY OPTIONS
Squid 1 1 - eth2 192.168.2.99 -
eth0 connects to ISP 1. The IP address of eth0
is 126.96.36.199 and the ISP's gateway router has IP address
eth1 connects to ISP 2. The IP address of eth1 is 188.8.131.52 and the ISP's
gateway router has IP address 184.108.40.206.
eth2 connects to a local network.
#NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY OPTIONS COPY
ISP1 1 1 main eth0 220.127.116.11 track,balance eth2
ISP2 2 2 main eth1 18.104.22.168 track,balance eth2
shorewall(8), shorewall-accounting(5), shorewall-actions(5),
shorewall-blacklist(5), shorewall-hosts(5), shorewall_interfaces(5),
shorewall-ipsets(5), shorewall-maclist(5), shorewall-masq(5),
shorewall-nat(5), shorewall-netmap(5), shorewall-params(5),
shorewall-policy(5), shorewall-proxyarp(5), shorewall-rtrules(5),
shorewall-routestopped(5), shorewall-rules(5), shorewall.conf(5),
shorewall-secmarks(5), shorewall-tcclasses(5), shorewall-tcdevices(5),
shorewall-mangle(5), shorewall-tos(5), shorewall-tunnels(5),