Ubuntu Manpage: tcdevices - Shorewall Traffic Shaping Devices file

NAME

       tcdevices - Shorewall Traffic Shaping Devices file

SYNOPSIS

       /etc/shorewall/tcdevices

DESCRIPTION

Entries in this file define the bandwidth for interfaces on which you want traffic shaping
to be enabled.

If you do not plan to use traffic shaping for a device, don't put it in here as it limits
the throughput of that device to the limits you set here.

A note on the bandwidth definitions used in this file:

• don't use a space between the integer value and the unit: 30kbit is valid while 30
kbit is not.

• you can use one of the following units:

kbps
Kilobytes per second.

mbps
Megabytes per second.

kbit
Kilobits per second.

mbit
Megabits per second.

bps or number
Bytes per second.

• Only whole integers are allowed.

The columns in the file are as follows (where the column name is followed by a different
name in parentheses, the different name is used in the alternate specification syntax).

INTERFACE - [number:]interface
Name of interface. Each interface may be listed only once in this file. You may NOT
specify the name of an alias (e.g., eth0:0) here; see
http://www.shorewall.net/FAQ.htm#faq18

You may NOT specify wildcards here, e.g. if you have multiple ppp interfaces, you need
to put them all in here!

If the device doesn't exist, a warning message will be issued during "shorewall
[re]start" and "shorewall refresh" and traffic shaping configuration will be skipped
for that device.

Shorewall assigns a sequential interface number to each interface (the first entry in
the file is interface 1, the second is interface 2 and so on) You can explicitly
specify the interface number by prefixing the interface name with the number and a
colon (":"). Example: 1:eth0.

IN-BANDWIDTH (in_bandwidth) - {-|bandwidth[:burst]|~bandwidth[:interval:decay_interval]}
The incoming bandwidth of that interface. Please note that you are not able to do
traffic shaping on incoming traffic, as the traffic is already received before you
could do so. But this allows you to define the maximum traffic allowed for this
interface in total, if the rate is exceeded, the packets are dropped. You want this
mainly if you have a DSL or Cable connection to avoid queuing at your providers side.

If you don't want any traffic to be dropped, set this to a value to zero in which case
Shorewall will not create an ingress qdisc.Must be set to zero if the REDIRECTED
INTERFACES column is non-empty.

The optional burst option was added in Shorewall 4.4.18. The default burst is 10kb. A
larger burst can help make the bandwidth more accurate; often for fast lines, the
enforced rate is well below the specified bandwidth.

What is described above creates a rate/burst policing filter. Beginning with Shorewall
4.4.25, a rate-estimated policing filter may be configured instead. Rate-estimated
filters should be used with Ethernet adapters that have Generic Receive Offload
enabled by default. See Shorewall FAQ 97a[1].

To create a rate-estimated filter, precede the bandwidth with a tilde ("~"). The
optional interval and decay_interval determine how often the rate is estimated and how
many samples are retained for estimating. Please see
http://ace-host.stuart.id.au/russell/files/tc/doc/estimators.txt for details.

OUT-BANDWIDTH (out_bandwidth) - bandwidth
The outgoing bandwidth of that interface. This is the maximum speed your connection
can handle. It is also the speed you can refer as "full" if you define the tc classes
in shorewall-tcclasses[2](5). Outgoing traffic above this rate will be dropped.

OPTIONS -
{-|{classify|htb|hfsc|linklayer={ethernet|atm|adsl}|tsize=tsize|mtu=mtu|mpu=mpu|overhead=overhead}
,...}
classify — When specified, Shorewall will not generate tc or Netfilter rules to
classify traffic based on packet marks. You must do all classification using CLASSIFY
rules in shorewall-tcrules[3](5).

htb - Use the Hierarchical Token Bucket queuing discipline. This is the default.

hfsc - Shorewall normally uses the Hierarchical Token Bucket queuing discipline. When
hfsc is specified, the Hierarchical Fair Service Curves discipline is used instead
(see tc-hfsc (7)).

linklayer - Added in Shorewall 4.5.6. Type of link (ethernet, atm, adsl). When
specified, causes scheduler packet size manipulation as described in tc-stab (8). When
this option is given, the following options may also be given after it: mtu=mtu - The
device MTU; default 2048 (will be rounded up to a power of two)

mpu=mpubytes - Minimum packet size used in calculations. Smaller packets will be
rounded up to this size

tsize=tablesize - Size table entries; default is 512

overhead=overheadbytes - Number of overhead bytes per packet.

REDIRECTED INTERFACES (redirect)- [interface[,interface]...]
May only be specified if the interface in the INTERFACE column is an Intermediate
Frame Block (IFB) device. Causes packets that enter each listed interface to be passed
through the egress filters defined for this device, thus providing a form of incoming
traffic shaping. When this column is non-empty, the classify option is assumed.

EXAMPLES

       Example 1:
           Suppose you are using PPP over Ethernet (DSL) and ppp0 is the interface for this. The
           device has an outgoing bandwidth of 500kbit and an incoming bandwidth of 6000kbit

                       #INTERFACE   IN-BANDWIDTH    OUT-BANDWIDTH         OPTIONS         REDIRECTED
                       #                                                                  INTERFACES
                       1:ppp0         6000kbit        500kbit

FILES

       /etc/shorewall/tcdevices

NOTES