Technical data

4. Packages

BRIDGE_DEV_2_DEV_1='bond0.22'

BRIDGE_DEV_2_DEV_2='eth3'

BRIDGE_DEV_3_NAME='_VLAN33_'

BRIDGE_DEV_3_DEVNAME='br33'

BRIDGE_DEV_3_DEV_N='2'

BRIDGE_DEV_3_DEV_1='bond0.33'

BRIDGE_DEV_3_DEV_2='eth4'

BRIDGE_DEV_4_NAME='_VLAN44_'

BRIDGE_DEV_4_DEVNAME='br44'

BRIDGE_DEV_4_DEV_N='2'

BRIDGE_DEV_4_DEV_1='bond0.44'

BRIDGE_DEV_4_DEV_2='eth5'

As a result all 4 Nets are connected with each other absolutely transparent and share the

200 Mbit/s connection. Even with a failure of one 100 Mbit/s line the connection will not fail.

If necessary EBTables support can also be activated e.g. to activate certain packet ﬁlter.

This conﬁguration is set up on two ﬂi4l routers. I think this is an impressive example what

the advanced_networking package can do.

4.3. CHRONY - Network Time Protocol Server/Client

OPT_CHRONY extends ﬂi4l with the Network Time Protocol (Page 92) (NTP). Don’t mix

it up with the normal Time Protocol, the old OPT_TIME provides. The protocols aren’t

compatible wich possibly raises the need of new client-side programs, which understand NTP.

If you can’t abandon the simple time protocol, chrony can provide it as well. OPT_CHRONY

works both as a server and client. Working as a client, OPT_CHRONY adjusts the time of

the ﬂi4l according to time referencies (time servers) in the internet. The basic setting uses

up to three time servers from pool.ntp.org (Page 92). However it’s possible to use a diﬀerent

selection of time servers in the conﬁguration ﬁle. Thus it’s possible to use time servers near

you, if you choose de.pool.ntp.org if the router or your provider sits in Germany. For more

details, look at the website of pool.ntp.org (Page 92).

Working as a client, OPT_CHRONY acts as a time reference for the local network (LAN).

NTP uses port 123.

Chrony doesn’t need a permanent connection to the internet. When the connection drops,

chrony get’s a notice and ceases the adjustion with the internet time servers. Neither does

chrony dial to raise the connection nor prevent the automatic hangup, if HUP_TIMEOUT, the

duration where no data is routet to the internet, is reached.

In order to do time adjustments smoothly, the following should be in mind:

• Chrony expects the BIOS-clock to be in UTC timezone. If not, it has to be conﬁgured

in the conﬁguration ﬁle.

UTC = German time minus 1 (winter) or 2 (summer) hour(s)

• Since version 2.1.12 chrony sets the time during the ﬁrst connection to the internet correct

even if the time diﬀerence is huge (caused by an empty mainboard battery for example).

• If the BIOS isn’t capable of handling years after 1999 (Year 2000 Bug) or if the BIOS

clock is faulty, activate OPT_Y2K=’yes’ (Page 75)!