538 BigIron RX Series Configuration Guide
53-1002253-01
Configuring numbered and named ACLs
21
Parameters to alter a packet’s QoS value
The parameters discussed in the sections above are used to filter packets. If the packets match the 
filters in an ACL statement, the packet is either permitted or denied. Once a packet is permitted, 
you can alter its QoS value by assigning a new DSCP value, 802.1p priority, and internal forwarding 
priority to the packet by doing one of the following:
• Specify a new QoS value to the packet by entering values for the following parameters.
Syntax: dscp-marking <number> 802.1p-priority-marking <number> internal-priority-marking 
<number>
For example, you enter the following.
dscp-marking 12 802.1p-priority-marking 1 internal-priority-marking 5
The packet’s new QoS value is:
• 802.1p (COS) value: 1
• DSCP value: 12
• Internal Forwarding Priority: 5
• Specify a DSCP value and map that value to an internal QoS table to obtain the packet’s new 
QoS value. Use the following parameters.
dscp-marking <number> dscp-cos-mapping
The following occurs when you use these parameters: 
• Enter 0 – 63 for the dscp-marking <number> parameter. 
• tos <name> | <num> Specify the IP ToS name or number.  You can specify one of the following:
• max-reliability or 2 – The ACL matches packets that have the 
maximum reliability ToS.  The decimal value for this option is 2.
• max-throughput or 4 – The ACL matches packets that have the 
maximum throughput ToS.  The decimal value for this option is 4.
• min-delay or 8 – The ACL matches packets that have the minimum 
delay ToS.  The decimal value for this option is 8.
• normal or 0 – The ACL matches packets that have the normal ToS.  
The decimal value for this option is 0.
• <num> – A number from 0 – 15 that is the sum of the numeric 
values of the options you want.  The ToS field is a four-bit field 
following the Precedence field in the IP header.  You can specify one 
or more of the following.  To select more than one option, enter the 
decimal value that is equivalent to the sum  of the numeric values 
of all the ToS options you want to select.  For example, to select the 
max-reliability and min-delay options, enter number 10.  To select 
all options, select 15.  
• 802.1p-priority-matching <number> Only packets that have the specified 802.1p priority will be matched. 
Valid range is 0-7.
dscp-marking <number> If a packet matches the filters in the ACL statement, this parameter assigns the  
DSCP value that you specify to the packet.  Enter 0 – 63.
802.1p-priority-marking 
<number>
If a packet matches the filters in the ACL statement, this parameter assigns the 
802.1p priority that you specify to the packet.  Enter 0 – 7.
internal-priority-marking 
<number>
If a packet matches the filters in the ACL statement, this parameter assigns the 
internal priority that you specify to the packet. Enter 0 – 7.