Technical data

3. Base configuration
you want the router to receive its IP address dynamically via a DHCP-client it is possible
to set this variable to ’dhcp’.
The following table shows how the CIDR notation and the dot notation for net masks
are connected.
CIDR Net mask Number of IP addresses
/8 255.0.0.0 16777216
/16 255.255.0.0 65536
/23 255.255.254.0 512
/24 255.255.255.0 256
/25 255.255.255.128 128
/26 255.255.255.192 64
/27 255.255.255.224 32
/28 255.255.255.240 16
/29 255.255.255.248 8
/30 255.255.255.252 4
/31 255.255.255.254 2
/32 255.255.255.255 1
Note: As one address is reserved for the network and one for broadcasting, the max-
imum number of hosts in the network is computed by: Number_Hosts = Number_IPs
- 2. Consequently, the smallest possible net mask is /30 which corresponds to four IP
addresses and hence to two possible hosts.
IP_NET_x_DEV Default Setting: IP_NET_1_DEV=’eth0’
Required: device name of the network adapter.
Starting with version 2.1.8, the name of the device used has to be supplied! Names
of network devices typically start with ’eth’ followed by a number. The first network
adapter recognized by the system receives the name ’eth0’, the second one ’eth1’ and
so on.
Example:
IP_NET_1_DEV='eth0'
The fli4l router is also able to do IP aliasing, i.e. to assign multiple IP addresses to a
single network adapter. Additional IP addresses are simply specified by linking another
network to the same device. When mkfli4l checks the configuration you are informed
that you define such an alias—you can ignore the warning in this case.
Example:
IP_NET_1='192.168.6.1/24'
IP_NET_1_DEV='eth0'
IP_NET_2='192.168.7.1/24'
IP_NET_2_DEV='eth0'
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