This module matches the 8-bit Type of Service field in the IPv4 header (i.e.

including the "Precedence" bits) or the (also 8-bit) Priority field in the IPv6

header.

.TP

[\fB!\fP] \fB\-\-tos\fP \fIvalue\fP[\fB/\fP\fImask\fP]

Matches packets with the given TOS mark value. If a mask is specified, it is

logically ANDed with the TOS mark before the comparison.

.TP

[\fB!\fP] \fB\-\-tos\fP \fIsymbol\fP

You can specify a symbolic name when using the tos match for IPv4. The list of

recognized TOS names can be obtained by calling iptables with \fB\-m tos \-h\fP.

Note that this implies a mask of 0x3F, i.e. all but the ECN bits.