39. Traffic Control
ROX™ v2.2 User Guide
475
RuggedBackbone™ RX1500
Mask to process the mark with
op-chain
Synopsis: string - one of the following keywords { prerouting, forward }
Default: forward
Chain in which the operation will take place
Figure 39.21. Continue form
continue-chain
Synopsis: string - one of the following keywords { prerouting, forward }
Default: forward
Chain in which the operation will take place
Hints on optimizing the TC Rule table
Every rule is processed in table order for every packet, unless a CONTINUE rule is matched, in which
case processing stops. This can be used to improve efficiency in combination with the SAVE and
RESTORE rules. For example, consider a TC Rules table organized roughly as follows (and in the
same order):
• A RESTORE rule is used to restore the connection's mark to a matching, unmarked packet
• A CONTINUE if the mark is non zero
• Specific rules to check criteria to assign a mark, and finally
• A SAVE mark to connection if the mark is non zero (that is, a match was found above)
Using the above structure for the TC Rules table, only the first packet of any tcp or udp connection will
have to go through all the rules, while every following packet will have its mark restored by the first rule,
and then CONTINUE, skipping potentially many matching rules in the remainder of the table.
