Management Prioritizing; Handling Of Received Priority Information - Hirschmann MACH 4000 User Manual

Network load control

8.4.4 Management prioritizing

In order for you to have full access to the management of the Switch, even
when there is a high network load, the Switch enables you to prioritize man-
agement packets.
In prioritizing management packets (SNMP, Telnet, etc.), the Switch sends
the management packets with priority information.
On Layer 2 the Switch modifies the VLAN priority in the VLAN tag.
For this function to be useful, the configuration of the corresponding ports
must permit the sending of packets with a VLAN tag.
On Layer 3 the Switch modifies the IP-DSCP value.

8.4.5 Handling of received priority information

The Switch provides three options, which can be chosen per port, for select-
ing how it handles received data packets that contain priority information.
trust dot1p
The Switch assigns VLAN-tagged packets to the different traffic classes
according to their VLAN priorities. The assignment is based on the pre-
defined table (see on page 18 "VLAN
signment. The Switch assigns the port priority to packets that it receives
without a tag.
untrusted
The Switch ignores the priority information in the packet and always as-
signs the packets the port priority of the receiving port.
trust ip-dscp
The Switch assigns the IP packets to the different traffic classes accord-
ing to the DSCP value in the IP header, even if the packet was also VLAN-
tagged. The assignment is based on the pre-defined values
13). You can modify this assignment.
The Switch prioritizes non-IP packets according to the port priority.
Basic - L3P
Release 4.0 11/07
tagging"). You can modify this as-
8.4 QoS/Priority
(see table
23