NAME

       firehol-router - create a router definition

SYNOPSIS

       { router | router46 } name rule-params

       router4 name rule-params

       router6 name rule-params

DESCRIPTION

       A  router  definition  consists  of  a  set  of rules for traffic passing through the host
       running the firewall.

       The default policy for router definitions is RETURN, meaning packets are  not  dropped  by
       any  particular  router.   Packets not matched by any router are dropped at the end of the
       firewall.

       The behaviour of the defined router is controlled by adding subcommands from those  listed
       in ROUTER SUBCOMMANDS.

              Note

              Writing router4 is equivalent to writing ipv4 router and ensures the defined router
              is created only in the IPv4 firewall along with any rules within it.

              Writing router6 is equivalent to writing ipv6 router and ensures the defined router
              is created only in the IPv6 firewall along with any rules within it.

              Writing  router46  is  equivalent  to  writing  both router and ensures the defined
              router is created in both the IPv4 and IPv6 firewalls.  Any rules  within  it  will
              also be applied to both, unless they specify otherwise.

PARAMETERS

       name   This is a name for this router.  You should use short names (10 characters maximum)
              without spaces or other symbols.

              A name should be unique for all FireHOL interface and router definitions.

       rule-params
              The set of rule parameters to further restrict the traffic that is matched to  this
              router.

              See  firehol-params(5)  for  information  on the parameters that can be used.  Some
              examples:

                     router mylan inface ppp+ outface eth0 src not ${UNROUTABLE_IPS}

                     router myrouter

              See firehol.conf(5) for an explanation of ${UNROUTABLE_IPS}.

WORKING WITH ROUTERS

       Routers create stateful iptables(8) rules which match traffic in both directions.

       To match some client or server traffic, the input/output interface  or  source/destination
       of the request must be specified.  All inface/outface and src/dst firehol-params(5) can be
       given on the router statement (in which case they will be applied to all  subcommands  for
       the router) or just within the subcommands of the router.

       For example, to define a router which matches requests from any PPP interface and destined
       for eth0, and on this allowing HTTP servers (on eth0) to be accessed by clients (from PPP)
       and SMTP clients (from eth0) to access any servers (on PPP):

              router mylan inface ppp+ outface eth0
                server http accept
                client smtp accept

              Note

              The  client  subcommand reverses any optional rule parameters passed to the router,
              in this case the inface and outface.

       Equivalently, to define a router which matches all forwarded traffic and  within  the  the
       router  allow  HTTP servers on eth0 to be accessible to PPP and any SMTP servers on PPP to
       be accessible from eth0:

              router mylan
                server http accept inface ppp+ outface eth0
                server smtp accept inface eth0 outface ppp

              Note

              In this instance two server subcommands are used since there are no  parameters  on
              the  router  to  reverse.  Avoid the use of the client subcommand in routers unless
              the inputs and outputs are defined as part of the router.

       Any number of routers can be defined and the traffic they match can  overlap.   Since  the
       default policy is RETURN, any traffic that is not matched by any rules in one will proceed
       to the next, in order, until none are left.

SEE ALSO

       • firehol(1) - FireHOL program

       • firehol.conf(5) - FireHOL configuration

       • firehol-params(5) - optional rule parameters

       • firehol-modifiers(5) - ipv4/ipv6 selection

       • firehol-interface(5) - interface definition

       • firehol-iptables(5) - iptables helper

       • firehol-masquerade(5) - masquerade helper

       • FireHOL Website (http://firehol.org/)

       • FireHOL Online PDF Manual (http://firehol.org/firehol-manual.pdf)

       • FireHOL Online Documentation (http://firehol.org/documentation/)

   Router Subcommands
       • firehol-policy(5) - policy command

       • firehol-protection(5) - protection command

       • firehol-server(5) - server, route commands

       • firehol-client(5) - client command

       • firehol-group(5) - group command

       • firehol-tcpmss(5) - tcpmss helper

AUTHORS

       FireHOL Team.