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br2684ctl - Man Page

RFC1483/2684 Bridge Daemon


br2684ctl [ -b ] [[ -c n ] [ -e 0|1 ] [ -p 0|1 ] [ -s sndbuf ] [ -a [itf].vpi.vci ]] ...


-a [itf].vpi.vci

ATM PVC number, VPI and VCI.  (Required)


Puts the process in the background.

-c n

br2684 interface number such as 0, 1, ... (Required)

-e 0|1

Encapsulation method:  0=LLC, 1=VC mux (the default is 0 or LLC)

-p 0|1

Payload method:  0=Routed, 1=Bridged (the default is 1 or Bridged)

-s sndbuf

Send buffer size. Default is 8192.


br2684ctl handles RFC1483/2684 bridged PDUs. This is most often used in ADSL scenarios where usually the subscribers' ethernet traffic is encapsulated in ATM AAL5 (by bridging ADSL modems) according to RFC2684.  The subscriber-side ADSL modem can be external with an ethernet connector  or an internal ADSL card in a PC. RFC1483 has been obsoleted by RFC2684.

For example it is possible to set up your Linux box to handle several ATM PVC's with bridged-1483 (sometimes referred as SNAP) encapsulation. The Linux network stack might provide DHCP, IP masquerading, IP firewall services or bridge the Ethernet frames just like it had several ethernet interfaces. In fact it can have several (logical) ethernet interfaces, where ATM is just used as a carrier.


br2684ctl creates a new network interface named nas[n] which is bound to an specific ATM PVC. It requires two mandatory arguments:  -c, the interface number, and -a, the ATM PVC. It should be noted that the order of the command arguments matter; -c should be followed by -a. You can create as many interfaces as necessary in one go, just make a long command line ;)

For example, following command will create a nas0 interface which uses the ATM PVC with VPI=0 and VCI=401. You need to configure the PVC connection 0.401 on the ATM switch manually.

% br2684ctl -c 0 -a 0.401

The command will only create a new interface nas0. Next step is to assign an IP address and netmask to the interface nas0 using the ifconfig command. Using ifconfig, you can also assign a Ethernet MAC address to the interface nas0, if necessary.

% ifconfig nas0 netmask

Messages are logged to the LOCAL2 syslog facility.




This man page is based on a tutorial by by Joonbum Byun <jbyun@megaxess.com>

See Also



7 Jul 2003