dn42/templates/bird/bird.conf.j2

# Device status
protocol device {
  scan time 10; # recheck every 10 seconds
}

protocol static {
  # Static routes to announce your own range(s) in dn42
  route {{ dn42_local_subnet_v4 }} reject;
  import all;
  export none;
};

# local configuration
######################

# keeping router specific in a seperate file,
# so this configuration can be reused on multiple routers in your network
include "/etc/bird/local4.conf";

# filter helpers
#################

##include "/etc/bird/filter4.conf";

# Kernel routing tables
########################

/*
    krt_prefsrc defines the source address for outgoing connections.
    On Linux, this causes the "src" attribute of a route to be set.

    Without this option outgoing connections would use the peering IP which
    would cause packet loss if some peering disconnects but the interface
    is still available. (The route would still exist and thus route through
    the TUN/TAP interface but the VPN daemon would simply drop the packet.)
*/
protocol kernel {
  scan time 20;
  import none;
  export filter {
    if source = RTS_STATIC then reject;
    krt_prefsrc = OWNIP;
    accept;
  };
};
# DN42
#######

template bgp dnpeers {
  local as OWNAS;
  # metric is the number of hops between us and the peer
  path metric 1;
  # this lines allows debugging filter rules
  # filtered routes can be looked up in birdc using the "show route filtered" command
  import keep filtered;
  import filter {
    # accept every subnet, except our own advertised subnet
    # filtering is important, because some guys try to advertise routes like 0.0.0.0
    if is_valid_network() && !is_self_net() then {
      accept;
    }
    reject;
  };
  export filter {
    # here we export the whole net
    if is_valid_network() && source ~ [RTS_STATIC, RTS_BGP] then {
      accept;
    }
    reject;
  };
  import limit 1000 action block;
  #source address OWNIP;
};

include "/etc/bird/peers4/*";