QoS
Lab file
Startup configs
IP addressing, IGP in the core (ISIS), Segment Routing, IGP at the customer sites (OSPF), BGP vpnv4, PE-CE routing (which uses OSPF) is all pre-configured.
Configure the CEs to mark traffic on input from the C routers:
Protocol
Marking
ICMP
IPP2
Telnet
IPP3
SSH
IPP4
On both C routers, generate ICMP, telnet, and SSH traffic and verify that the IPP value is set correctly. Use the pre-configured policy-map applied to Gi1 of both C routers to verify hits on the correct IPP values. Telnet and SSH are already enabled on the C routers, however you need to generate the crypto key (crypto key gen rsa). The login is cisco/cisco.
In the service provider core, configure the following outbound queuing policy and apply to all core interfaces. Classification should be based on the EXP value. The IPP of the customer traffic is automatically mapped to the EXP value at the ingress PE.
IPP Value
Action
0
WFQ
2
Police at 256Kbps. If over 256Kbps but under 512Kbps, mark down to IPP0. If over 512Kbps, discard.
3
Allocate 5 Mbps of bandwidth gauranteed
4
LLQ with a policer set at 10 Mbps
Also ensure that a PE router will see the marking of the topmost label in the core. In case a P router changes the topmost label, we want the PE router to be able to use the topmost EXP value. Additionally ensure that the PE routers make egress queuing decisions towards the CEs based on the MPLS EXP and not the customer’s IP traffic.
Generate customer traffic again and verify hits on the policies on the core routers.
3. On PE1 and PE4 enforce 100M symmetrical bandwidth but continue using the queuing policy.
Answers
You can use NBAR (match protocol) or ACLs (match access-group) to match traffic. Use a policy-map to set the IPP value.
On the C routers, generate traffic and use the following command to ensure that traffic is being marked to the correct IPP value.
2. IOS-XE
IOS-XR:
To ensure that the EXP value of the top (transport) label is received at the egress PE, you must advertise the prefix SID with an explicit null.
To queue traffic outbound on the interface facing the CEs, the PEs must associate the EXP value with a QoS-group and then preform policy based on the QoS-group.
3. On the PEs, create a service-policy that shapes and polices at 100M. On the shaper, nest the queuing policy.
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