2 FastDPI L2 BRAS setup

The activation of the fastDPI BRAS features is done according to the mandatory settings defined in the fastdpi.conf configuration file:

bras_enable=1 – the common flag to enable the BRAS

bras_arp_ip – specifies the BRAS IPv4 address. You are allowed to set a fake IP addres, which is not connected to any network interface. The main requirement is that the IP address should be unique, i.e. it should not correspond to any user.

bras_arp_mac – the BRAS MAC address in the following format: XX:XX:XX:XX:XX:XX, for example, a0:00:b1:01:4e:cc. This MAC address have to be unique within the whole local network; fake MAC can be used instead, it should not be connected to any network card, but in order to avoid an accidental match with other MAC address of client's equipment we strongly recommend to use the real dna card MAC address instead.

auth_servers - specifies the list of the fastPCRF servers. FastPCRF server is responsible for interaction with Radius servers. Used format to specify the server: ip%dev:port, here ip - is the server IP address, dev - the local device used to establish connection. FastDPI establishes connection with the first available fastPCRF server from the list.

In order the fastDPI BRAS to work properly BRAS have to be enabled UDR (user data repository is the internal database containing user properties): the fastdpi.conf should contain the following line udr=1

Example:

udr=1 auth_servers=127.0.0.1%lo:29002 bras_enable=1 bras_arp_ip=192.168.1.255 bras_arp_mac=a0:00:b1:01:4e:cc
When choosing the bras_arp_mac parameter, it is very convenient to use the existing MAC address of the card port. But it was noticed that some advanced cards (for example, 25G cards on the XXV710 chip, i40e driver) can destroy some packets (for example, ARP) if bras_arp_mac is equal to the MAC address of the card port. The reason for this behavior is not clear, therefore, in order to avoid packet loss, we advise you to select the bras_arp_mac value purely virtual, not matching the MAC address of the port.
Some special fastDPI BRAS features are enabled by corresponding advanced settings described further, but without the bras_enable=1 flag the special features will be unavailable.

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