How to implement qos in 3925 router IOS using dscp ?

[kishore]

I have a 3925 cisco router which is connected to SG 350 Semi manageable switch. I have an isp with 200 Mbps connection. I want port 3 of switch to get 20 Mbps only. Port 3 is in vlan 20.

I have done till this only

Router

int gig0/0

ip address 192.168.52.1 255.255.255.0

no shutdown

ip dhcp pool vlan20

network 10.0.0.0 255.0.0.0

default-router 10.0.0.1

dns-server 8.8.8.8

int gig0/0.20

encapsulation dot1q 20

ip address 10.0.0.1 255.0.0.0

Int gig0/0 of router is connected to gig0/1 of switch

Switch

vlan 20

exit

int gig0/3

switchport mode access

switchport access vlan 20

int gig0/1

switchport mode trunk

So how to implement qos using dscp, such that i should 20 Mbps on port 3 only. 

Please help me.

[Georg Pauwen]

Hello,

the easiest way to do this would be on the switch itself. Go to:

Quality of Service > General > Bandwidth.

then select the port and set the Ingress Rate Limit to 20Mbps.

Check page 499 of the attached user guide:

https://www.cisco.com/c/dam/en/us/td/docs/switches/lan/csbms/sf30x_sg30x/administration_guide/78-19308-01.pdf

[paul driver]

Hello

Usually you shouldn’t really need to apply Qos on the access layer as it has sufficient BW, So can you be more specific - You mention a router but you ask about a port on a switch?

Do you wish to rate limit (police) the traffic from a specific user off that port or from the port itself or certain ip range.

DSCP is a Layer 3 qos marking so if your need is to apply qos on the switch then you most probably need to defined the correct qos to dscp marking on the switch to accommodate.

res
Paul