Hi,
First at all, thank you with the great work you’re doing with NetworkLessons. After reading this lessons I have one doubt. If I understood it correctly from the “Introduction to Qos” lesson, QoS can only be applied to trunks interfaces or to routed interfaces according to the folowing words from Lazaros in that section’s forum:
“QoS functions at Layer 3 and Layer 2. Layer 3 QoS will operate when routing packets, as the QoS information is found within the header of the IP packet. At layer 2, QoS information is found within the 802.1Q tag, or the VLAN tag. This VLAN tag exists only on frames that traverse trunk ports. Since frames that enter and exit an access port do not have VLAN tags which contain the tagging information, QoS based on markings cannot be implemented at access ports. There is an exception to this rule, which is access ports that are configured with an additional voice VLAN. This is because voice VLAN frames do have a VLAN tag and can be handled differently than other frames”
However, in the current lesson it’s being applied to non-routed non-trunk interfaces. Did I miss something? The interfaces used in this lessons are configured as follow:
interface GigabitEthernet1/0/27
!
interface GigabitEthernet1/0/48
service-policy output BANDWIDTH-REMAINING
So there is no switchport mode trunk to convert them to trunks nor they have IP addresses making them routed interfaces.
Another question: what’s the difference between the priority command used in the previous lesson and the police rate command used in the previous. Both assign the traffic to a LLQ up to a certain maximum per second, don’t they?
Additionally, I’d like to point out 2 that I’ve detected a minor error: The sum “10 + 20 + 30 = 70 Mbps” is wrong. Those values sum 60, not 70.