and content of my writings, a good deal of the subject matter was a
little beyond him. In support of the fresh-faced sysadmins and those
that might be new to FreeBSD (we were all there once), this write up is
how to add static routes to a FreeBSD host. Our details for this are:
HOST: beastie PROMPT: beastie [0] OS: FreeBSD 8.1While the examples are performed on FreeBSD 8.1, they should equally
apply at least back to FreeBSD 4.8.
In the following example, a route is added for a management network with
a destination of 10.11.18.0/24. This network encompasses all addresses
starting from 10.11.18.0 and ending 10.11.18.255:
beastie [0] /sbin/route add -net 10.11.18.0/24 -iface em0 add net 10.11.18.0: gateway em0The route is added with a gateway of one of our network interfaces
(-iface em0), meaning the network is directly reachable through this
interface. In the next example, we add a route for a monitoring network.
The destination is 10.17.4.35, using 10.0.22.44 as the gateway and
255.255.255.224 as the netmask (addresses 10.17.4.32 - 10.17.4.63 (CIDR:
10.17.4.32/27)):
beastie [0] /sbin/route add -net 10.17.4.35 10.0.22.44 255.255.255.224 add net 10.17.4.35: gateway 10.0.22.44The above 'route' commands illustrate two different ways 'route' allows
for specifying a netmask for the network in question. The first uses
CIDR notation (/24) immediately following the destination. In the second
example, the netmask is specified following the gateway. Either way is
perfectly acceptable. In the next command, a host route for an operations
server is added for host 192.168.34.43, with 192.168.56.88 as the gateway:
beastie [0] /sbin/route add -host 192.168.34.43 192.168.56.88 add host 192.168.34.43: gateway 192.168.56.88A check of our routing table shows the newly added routes (I've identified
them with "<====" at the end of the lines):
beastie [0] /usr/bin/netstat -f inet -nr Routing tables Internet: Destination Gateway Flags Refs Use Netif Expire default 127.0.0.1 US 0 0 lo0 10.0.22.0/23 link#1 U 0 0 em0 10.0.23.181 link#1 UHS 0 0 lo0 10.0.23.182 link#1 UHS 0 0 lo0 10.11.18.0/24 08:00:27:ce:11:c0 US 0 0 em0 <==== 10.17.4.32/27 10.0.22.44 UGS 0 0 em0 <==== 127.0.0.1 link#3 UH 0 82 lo0 192.168.34.43 192.168.56.88 UGHS 0 0 em1 <==== 192.168.56.0/24 link#2 U 1 1287 em1 192.168.56.35 link#2 UHS 0 0 lo0In order to retain the above routes through a reboot, we need to update
'/etc/rc.conf'. To specify static routes, we add "static_routes" and
supply a double quoted, space delimited string as its value:
static_routes="monitoring management ops_server"Each element of the string gets a separate subsequent entry of
"route_ELEMENT" whose value is passed off to 'route add' during system
bootup:
route_monitoring="-net 10.11.18.0/24 -iface em0" route_management="-net 10.17.4.35 10.0.22.44 255.255.255.224" route_ops_server="-host 192.168.34.43 192.168.56.88"Of note, static routes need to be added after their dependent interfaces
are brought online. Also, while underscores (_) are accepted as part of
the element, hyphens (-) are not. Below are the contents of our updated
'/etc/rc.conf' accounting for our new static routes after our interfaces:
beastie [0] /usr/bin/grep -v ^# /etc/rc.conf defaultrouter="127.0.0.1" hostname="beastie" ifconfig_em0="inet 10.0.23.181 netmask 255.255.254.0" ipv4_addrs_em0="10.0.23.182/23" ifconfig_em1="inet 192.168.56.35 netmask 255.255.255.0" static_routes="monitoring management ops_server" route_monitoring="-net 10.11.18.0/24 -iface em0" route_management="-net 10.17.4.35 10.0.22.44 255.255.255.224" route_ops_server="-host 192.168.34.43 192.168.56.88" inetd_enable="YES" sshd_enable="YES" sendmail_enable="NO" sendmail_submit_enable="NO"
see also:
Static Routes in Solaris
Static Routes in Linux
