Technical data

4. Packages
• small mails can be sent but big mails can’t,
• ssh works, scp hangs after initial connecting.
To work around this problems fli4l manipulates the MTU as a default. In some cases
this is not enough so fli4l explicitely permits setting of the MSS (message segment size)
to a value given by the provider. If the provider does not give any values 1412 is a good
start to try. If a MTU is given by the provider, subtract 40 Byte here (mss mtu 40).
These variables are optional and can be completely omitted. These variable doesn’t exist
for OPT_PPTP.
4.6.2. OPT_PPPOE - DSL over PPPoE
For communication via a DSL connection usually the PPPoE package is necessary because the
provider does not provide a full blown router, but only a DSL modem. Between the fli4l router
and the modem the PPP protocol is used, but in this case specifically over Ethernet.
One or two ethernet cards can be used in fli4l:
• only one card with IP for the LAN and PPP towards the DSL-modem
• two cards: one with IP for the LAN, the other for PPP towards the DSL-modem
The better choice is to use two ethernet cards. This way both protocols - IP and PPPoE -
are clearly separated from each other.
But the method with one ethernet cards works as well. In this case the DSL-modem has to
be connected to the network hub like all other clients. The maximum transfer speed can be
slightly affected this way.
If experiencing communication problems between the modem and the network card you can
try to slow down the speed of the NIC, eventually even switching it to half-duplex mode. All
PCI cards but only a few PCI-ISA network cards can be configured to run in various speed
modes. Either use ethtool from the package advanced_networking or create a DOS boot media
and include the native configuration tool there. Start fli4l with this media and execute the
card’s native tool to choose and save the slower operation mode to the card. The configuration
tool usually is available on the driver media or can be downloaded from the website of the card
manufacturer. You may also find it in a search in the wiki:
• https://ssl.nettworks.org/wiki/display/f/Netzwerkkarten
If using two network cards you should use the first for the LAN and the second for the
connection to the DSL modem.
Only the first card does need an IP address.
This means:
IP_NET_N='1' # Only *one* card with IP-address!
IP_NET_1xxx='...' # Usual parameters
For PPPOE_ETH set the second ethernet card to ’eth1’ and define *no* IP_NET_2-xxx-variables.
OPT_PPPOE activates support for PPPoE. Default setting: OPT_PPPOE='no'.
108