QuistED.net

Building a case study from the ARCH FLG book; BGP communities.

The idea is to use BGP communities to influence the routing between Autonomous Systems with the following goals in mind:

• Configure communities to tag the routes per building on each AS.
• Configure communities as no-export so the routes of AS65001.building2 and AS65002.building2 are not exported through AS65000.
  • The routes will be tagged on R6 and R9 with community 65000:99 and processed on the AS boundry.
  • The routes of AS65001.building1 and AS65002.building1 are allowed to be exported.
• Configure communities so that R7 and R8 can set their local preference on the AS65000 side.
  • The routes will be tagged on R7 will be tagged with 65000:200 resulting in a local-preference of 200.
  • The routes will be tagged on R8 will be tagged with 65000:300 resulting in a local-preference of 300.

LAB:

LAYER3:

BGP Configuration:

AS65000 :

R1# (Change the network and neighbor addresses where needed for the other routers)
router bgp 65000
 bgp log-neighbor-changes
 network 10.0.1.0 mask 255.255.255.0
 neighbor ibgp peer-group
 neighbor ibgp remote-as 65000
 neighbor ibgp next-hop-self
 neighbor ibgp send-community
 neighbor ibgp soft-reconfiguration inbound
 neighbor 10.255.65.2 peer-group ibgp
 neighbor 10.255.65.3 peer-group ibgp
 neighbor 10.255.65.4 peer-group ibgp

AS65001 :

R5# (Change the network and neighbor addresses where needed for the other routers)
router bgp 65001
 bgp log-neighbor-changes
 network 10.0.111.0 mask 255.255.255.0
 neighbor ibgp peer-group
 neighbor ibgp remote-as 65001
 neighbor ibgp next-hop-self
 neighbor ibgp send-community
 neighbor ibgp soft-reconfiguration inbound
 neighbor 10.255.1.1 remote-as 65000
 neighbor 10.255.1.1 send-community
 neighbor 10.255.66.2 peer-group ibgp

AS65002 :

R7# (Change the network and neighbor addresses where needed for the other routers)
router bgp 65002
 bgp log-neighbor-changes
 network 10.0.221.0 mask 255.255.255.0
 neighbor ibgp peer-group
 neighbor ibgp remote-as 65002
 neighbor ibgp next-hop-self
 neighbor ibgp send-community
 neighbor ibgp soft-reconfiguration inbound
 neighbor 10.255.2.1 remote-as 65000
 neighbor 10.255.2.1 send-community
 neighbor 10.255.2.1 route-map EBGP-MAP out
 neighbor 10.255.67.2 peer-group ibgp
 neighbor 10.255.67.3 peer-group ibgp

Tagging routes on R6 and R9 (no export)

R9#:
access-list 101 permit ip host 10.0.222.0 host 255.255.255.0
!
route-map TAGROUTE permit 10     
 match ip address 101                    # MATCH THE ROUTES YOU WANT TO TAG
 set community 65000:99 65002:5202       # SET COMMUNITIES 65000:99 (no export) and 65000:5202 ( site ID) 

Router bgp 65002
- snip -
neighbor ibgp route-map TAGROUTE out     # APPLY ROUTEMAP ON OUTGOING ROUTES TOWARDS R7 + R8 
- snap - 

Verify on R7 and R8:

R7#sh ip bgp 10.0.222.0
BGP routing table entry for 10.0.222.0/24, version 3
Paths: (1 available, best #1, table default)
  Advertised to update-groups:
     9
  Refresh Epoch 1
  Local, (received & used)
    10.255.67.3 from 10.255.67.3 (10.0.222.1)
      Origin IGP, metric 0, localpref 100, valid, internal, best
      Community: 65000:99 65002:5202
      rx pathid: 0, tx pathid: 0x0

Confuring communities on R7 and R8 ( Site-ID’s and Local pref community )

R7:
access-list 101 permit ip host 10.0.221.0 host 255.255.255.0
!
route-map EBGP-MAP permit 10
 match ip address 101
 set community 65000:200 65002:5101
!
route-map EBGP-MAP permit 20
!
Router bgp 65002:
neighbor 10.255.2.1 route-map EBGP-MAP out

R8:
access-list 101 permit ip host 10.0.221.0 host 255.255.255.0
!
route-map EBGP-MAP permit 10
 match ip address 101
 set community 65000:300 65002:5101
!
route-map EBGP-MAP permit 20
!
Router bgp 65002:
neighbor 10.255.3.1 route-map EBGP-MAP out

What this will accomplish is that a local pref community is send to AS65000 with resulting values of 200 for R7 and 300 for R8 for the 10.0.221.0/24 route.

Confuring the community settings on R3 and R4 ( No export and Local pref )

R3# and R4#:
ip community-list 1 permit 65000:99        # The no-export community from R6 and R9 
ip community-list 2 permit 65000:200       # The localpref community for value 200
ip community-list 3 permit 65000:300       # The localpref community for value 300
!
route-map TAG-IN permit 10
 match community 1
 set community no-export
!
route-map TAG-IN permit 20
 match community 2
 set local-preference 200
!
route-map TAG-IN permit 30
 match community 3
 set local-preference 300
!
route-map TAG-IN permit 40                  # This to allow all other routes if there were any.

router bgp 65000
 neighbor 10.255.3.2 route-map TAG-IN in

This will give R4 a higher local pref (300) for route 10.0.221.0/24 towards R8. Resulting in the following result from R3’s prespective:

R3#sh ip route 10.0.221.1
Routing entry for 10.0.221.0/24
  Known via "bgp 65000", distance 200, metric 0
  Tag 65002, type internal
  Last update from 10.255.65.4 03:51:18 ago
  Routing Descriptor Blocks:
  * 10.255.65.4, from 10.255.65.4, 03:51:18 ago        # R4 is the next hop
      Route metric is 0, traffic share count is 1
      AS Hops 1
      Route tag 65002
      MPLS label: none


R3#sh ip bgp 10.0.221.0
BGP routing table entry for 10.0.221.0/24, version 7
Paths: (2 available, best #1, table default)
  Advertised to update-groups:
     9
  Refresh Epoch 1
  65002, (received & used)
    10.255.65.4 from 10.255.65.4 (10.255.65.4)
      Origin IGP, metric 0, localpref 300, valid, internal, best
      Community: 65000:300 65002:5101
      rx pathid: 0, tx pathid: 0x0
  Refresh Epoch 1
  65002
    10.255.2.2 from 10.255.2.2 (10.255.67.1)
      Origin IGP, metric 0, localpref 200, valid, external
      Community: 65000:200 65002:5101
      rx pathid: 0, tx pathid: 0

Verifying the no-export community

If all goes well we shouldn’t see the 10.0.112.0/24 and 10.0.222.0/24 routes exported through AS65000 ( And we don’t );

R1#sh ip route
-
      10.0.0.0/8 is variably subnetted, 10 subnets, 2 masks
C        10.0.1.0/24 is directly connected, Loopback0
L        10.0.1.1/32 is directly connected, Loopback0
B        10.0.2.0/24 [200/0] via 10.255.65.2, 03:36:08
B        10.0.3.0/24 [200/0] via 10.255.65.3, 03:36:07
B        10.0.111.0/24 [200/0] via 10.255.65.2, 03:36:08
B        10.0.112.0/24 [200/0] via 10.255.65.2, 03:36:08        #AS6500 Sees the AS65001 route
B        10.0.221.0/24 [200/0] via 10.255.65.4, 03:36:07
B        10.0.222.0/24 [200/0] via 10.255.65.3, 03:36:07        #AS6500 Sees the AS65002 route
C        10.255.65.0/24 is directly connected, FastEthernet0/0
L        10.255.65.1/32 is directly connected, FastEthernet0/0

R6#sh ip route
      10.0.0.0/8 is variably subnetted, 9 subnets, 2 masks
B        10.0.1.0/24 [200/0] via 10.255.66.1, 03:37:08
B        10.0.2.0/24 [200/0] via 10.255.66.1, 03:37:08
B        10.0.3.0/24 [200/0] via 10.255.66.1, 03:36:39
B        10.0.111.0/24 [200/0] via 10.255.66.1, 00:00:03
C        10.0.112.0/24 is directly connected, Loopback0
L        10.0.112.1/32 is directly connected, Loopback0
B        10.0.221.0/24 [200/0] via 10.255.66.1, 03:36:39
C        10.255.66.0/24 is directly connected, FastEthernet0/0
L        10.255.66.2/32 is directly connected, FastEthernet0/0
                                                          #AS65001 is missing the 10.0.222.0/24 route

R9#sh ip route
      10.0.0.0/8 is variably subnetted, 9 subnets, 2 masks
B        10.0.1.0/24 [200/0] via 10.255.67.1, 03:34:29
B        10.0.2.0/24 [200/0] via 10.255.67.1, 03:34:29
B        10.0.3.0/24 [200/0] via 10.255.67.1, 03:34:29
B        10.0.111.0/24 [200/0] via 10.255.67.1, 03:34:29
B        10.0.221.0/24 [200/0] via 10.255.67.1, 03:41:11
C        10.0.222.0/24 is directly connected, Loopback0
L        10.0.222.1/32 is directly connected, Loopback0
C        10.255.67.0/24 is directly connected, FastEthernet0/0
L        10.255.67.3/32 is directly connected, FastEthernet0/0
                                                         #AS65002 is missing the 10.0.112.0/24 route

Next up, Datacenter!

200-150

• Data Center Physical Infrastructure
• Basic Data Center Networking Concepts
• Advanced Data Center Networking Concepts
• Basic Data Center Storage
• Advanced Data Center Storage

https://learningcontent.cisco.com/cln_storage/text/cln/marketing/exam-topics/200-150-dcicn.pdf

200-155

• Unified Computing
• Network Virtualization
• Cisco Data Center Networking Technologies
• Automation and Orchestration
• Application Centric Infrastructure

https://learningcontent.cisco.com/cln_storage/text/cln/marketing/exam-topics/200-155-dcict.pdf

https://en.wikipedia.org/wiki/Protocol_Independent_Multicast

• PIM Sparse Mode (PIM-SM) explicitly builds unidirectional shared trees rooted at a rendezvous point (RP) per group, and optionally creates shortest-path trees per source. PIM-SM generally scales fairly well for wide-area usage.

Packetcapture when generating traffic from the Video Server (R1) to the multicast group address 224.3.2.1.

Connectivity via OSPF:

On all routers:
router ospf 1
 network 0.0.0.0 255.255.255.255 area 0

R1#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     1.0.0.0/32 is subnetted, 1 subnets
O       1.1.1.1 [110/21] via 10.0.0.2, 00:14:46, FastEthernet0/0
     20.0.0.0/24 is subnetted, 1 subnets
O       20.0.0.0 [110/20] via 10.0.0.2, 00:14:46, FastEthernet0/0
     10.0.0.0/24 is subnetted, 1 subnets
C       10.0.0.0 is directly connected, FastEthernet0/0
     30.0.0.0/24 is subnetted, 1 subnets
O       30.0.0.0 [110/30] via 10.0.0.2, 00:14:46, FastEthernet0/0

Multicast configuration:

On all routers:
# Enable Multicast routing
ip multicast-routing

#Enable PIM Sparse-mode on the interfaces
R1(config)#int fa0/0
R1(config-if)#ip pim sparse-mode
R1(config)#int fa0/1
R1(config-if)#ip pim sparse-mode

#Add RP address
ip pim rp-address 1.1.1.1

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Designing for Cisco Network Service Architectures (ARCH) Foundation Learning Guide: CCDP ARCH 300-320, 4th Edition:

• http://www.ciscopress.com/store/designing-for-cisco-network-service-architectures-arch-9780134426013

CCDP 300-320 videos courses:

• CBT Nuggets: https://www.cbtnuggets.com/it-training/cisco-ccdp-642-874-arch
  • It says 642-874 in the URL, but it’s updated for 300-320 ARCH 3.0.
• How to Network: https://www.howtonetwork.org/design/ccdp/
  • I was looking for an alternative source since INE.com doesn’t cover ARCH 3.0
• https://ine.com/products/642-873-arch-exam-course
  • This isn’t the ARCH 3.0 version.
• Cisco Learning Network: https://learningnetworkstore.cisco.com/ccdp/

Cisco Design Webinars:

• Practical Network Design Fundamentals – CCDP Webinars: https://learningnetwork.cisco.com/community/learning_center/practical-network-design-fundamentals

Cisco Arch Study Material:

• https://learningnetwork.cisco.com/community/certifications/ccdp/arch/study-material
• ARCH Exam topics: https://learningnetwork.cisco.com/community/certifications/ccdp/arch/exam-topics

Cisco Design Zone:

https://www.cisco.com/c/en/us/solutions/design-zone.html#~stickynav=3

• Campus: https://www.cisco.com/c/en/us/solutions/design-zone/networking-design-guides/campus-wired-wireless.html
• Datacenter:
  • https://www.cisco.com/c/en/us/solutions/design-zone/data-center-design-guides/data-center-design-guides-all.html
  • https://www.cisco.com/c/dam/en/us/solutions/collateral/enterprise-networks/enterprise-network-security/data-center-design-playbook.pdf
• Software defined Access: https://www.cisco.com/c/dam/en/us/td/docs/solutions/CVD/Campus/CVD-Software-Defined-Access-Design-Guide-2018JAN.pdf
• QoS: https://www.cisco.com/c/en/us/td/docs/solutions/CVD/Dec2017/APIC-EM-EasyQoS-DesignGuide-Dec2017.html
• IPv6 Design Zone: https://www.cisco.com/c/en/us/solutions/enterprise/design-zone-ipv6/index.html

Books / PDF

• CCDP ARCH Quick Reference ( Kevin Wallace ): http://www.ciscopress.com/store/ccdp-arch-quick-reference-9781587054990
• Enterprise Campus 3.0 Architecture: Overview and Framework: https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Campus/campover.pdf
• Optimal Routing Design (More in-depth and useable for CCDE): http://www.ciscopress.com/store/optimal-routing-design-9781587051876
• BGP Design & Implementation: http://www.ciscopress.com/store/bgp-design-and-implementation-9781587051098
• Top Down Network Design: http://www.ciscopress.com/store/top-down-network-design-9780133434989
• End-to-End QoS: http://www.ciscopress.com/store/end-to-end-qos-network-design-quality-of-service-for-9781587143694
• Enterprise QoS Solution Reference Network Design Guide: https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book.pdf
• Datacenter Design: https://www.cisco.com/c/dam/en/us/td/docs/solutions/CVD/Aug2014/CVD-DataCenterDesignGuide-AUG14.pdf
• Routing TCP/IP Volume 1 and 2: (Not so much design but great in-depth configuration books and a great resource on technical knowledge. Don’t let the CCIE tag scare you).
  • http://www.ciscopress.com/store/routing-tcp-ip-volume-1-9781587052026
  • http://www.ciscopress.com/store/routing-tcp-ip-volume-ii-ccie-professional-development-9781587054709

Videos:

• INE.com Introduction into IPv4 and IPv6 Multicast: https://www.youtube.com/watch?v=HEcz_gb4whQ&t=0s&list=PL3UpcvaDU_Fl-4zhNy_MxdQz8j8ySWCsu&index=1
• Solarwinds Cisco QoS: Design and Best Practices for Enterprise Networks: https://www.youtube.com/watch?v=xePZcobaJUY
• “Cisco Catalyst 3560 and 3750 QoS Simplified… Seriously!” By Kevin Wallace: https://www.youtube.com/watch?v=6UJZBeK_JCs

Cisco Guides:

• OSPF: https://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/7039-1.html
• Datacenter:
  • Campus 3.0 Virtual Switching System Design Guide: https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Campus/VSS30dg/campusVSS_DG/VSS-dg_ch1.html
  • Cisco Application Policy Infrastructure Controller Data Center Policy Model: https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-731310.html
  • Top-of-Rack / End-of-Row: https://www.cisco.com/c/en/us/products/collateral/switches/nexus-5000-series-switches/white_paper_c11-522337.html
  • vPC Best Practices: https://www.cisco.com/c/dam/en/us/td/docs/switches/datacenter/sw/design/vpc_design/vpc_best_practices_design_guide.pdf
  • OTV Best Practices: https://www.cisco.com/c/dam/en/us/products/collateral/switches/nexus-7000-series-switches/guide_c07-728315.pdf
• Traditional WAN Design Summary: https://www.cisco.com/c/dam/en/us/td/docs/solutions/CVD/Mar2017/CVD-WANDesign-MAR2017.pdf
• Cisco TrustSec
  • https://www.cisco.com/c/en/us/solutions/enterprise-networks/trustsec/design-guide-listing.html
  • https://www.cisco.com/c/dam/en/us/products/collateral/security/identity-services-engine/at_a_glance_c45-726831.pdf
• QoS
  • https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND_40/QoSCampus_40.html
• IPSec Direct Encapsulation VPN Design Guide
  • https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/WAN_and_MAN/Dir_Encap.html

Various Resources:

• Discord Cisco Study Group
• https://learningnetwork.cisco.com/thread/124036
• https://www.reddit.com/r/ccdp
• https://learningnetwork.cisco.com/groups/ccdp-study-group
• http://blog.ine.com/2010/11/19/ccdp-recommended-reading-list/

Cisco Live:

• Enterprise Campus Design: Multilayer Architectures and Design Principles – BRKCRS-2031
• WAN Architectures and Design Principles – BRKRST-2041
• Campus Wired LAN Deployment Using Cisco Validated Designs – BRKCRS-1500
• Campus QoS Design-Simplified – BRKCRS-2501
• OSPF Deployment in Modern Networks – BRKRST-2337
• EIGRP Deployment in Modern Networks – BRKRST-2336
• Advanced – Scaling BGP – BRKRST-3321
• Nexus Multicast Design Best Practices – BRKIPM-3062
• Cisco FabricPath Technology and Design – BRKDCT-2081
• Advanced Enterprise Campus Design: Converged Access – BRKCRS-2888
• Cisco Unified Contact Center Enterprise Planning and Design – BRKCCT-2007

OTV: Overlay Transport Virtualization

OTV(Overlay Transport Virtualization) is a technology that provide layer2 extension capabilities between different data centers.
In its most simplest form OTV is a new DCI (Data Center Interconnect) technology that routes MAC-based information by encapsulating traffic in normal IP packets for transit.

• Transparent workload mobility
• Business resiliency
• Superior computing resource efficiencies

References:

Cisco: OTV Quick Start Guide

Cisco: NX-OS OTV Configuration Guide

Cisco: OTV Best Practices

Cisco: OTV Whitepaper

OTV Encapsulation

OTV adds a further 42 bytes on all packets traveling across the overlay network. The OTV Edge device removes the CRC and 802.1Q fields from the original Layer2 frame. It then adds an OTV Shim Header which includes this 802.1Q field (this includes the priority P-bit value) and the Overlay ID information. It also includes an external IP header for the transport network. All OTV packets have Don’t Fragment (DF) bit set to 1 in the external IP header.

(more…)

A virtual PortChannel (vPC) allows links that are physically connected to two different Cisco Nexus™ 5000 Series devices to appear as a single PortChannel to a third device. The third device can be a Cisco Nexus 2000 Series Fabric Extender or a switch, server, or any other networking device. A vPC can provide Layer 2 multipathing, which allows you to create redundancy by increasing bandwidth, enabling multiple parallel paths between nodes and load-balancing traffic where alternative paths exist.

After you enable the vPC function, you create a peer keepalive link, which sends heartbeat messages between the two vPC peer devices.

The vPC domain includes both vPC peer devices, the vPC peer keepalive link, the vPC peer link, and all the PortChannels in the vPC domain connected to the downstream device. You can have only one vPC domain ID on each device.

• vPC Quick Configuration Guide
• Design and Best practices

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HUB (R1 ):

R1: 
interface FastEthernet0/0
 ip address 192.168.1.100 255.255.255.0
 duplex full

interface Tunnel0
 ip address 10.1.1.1 255.255.255.0  #TUNNEL CONFIG
 no ip redirects
 ip mtu 1416
 ip hold-time eigrp 1 35         #EIGRP CONFIG
 no ip next-hop-self eigrp 1     #EIGRP CONFIG
 no ip split-horizon eigrp 1     #EIGRP CONFIG
 ip nhrp map multicast dynamic   #NHRP CONFIG 
 ip nhrp network-id 1            #NHRP CONFIG 
 tunnel source 192.168.1.100     #TUNNEL CONFIG
 tunnel mode gre multipoint      #TUNNEL CONFIG
!
router eigrp 1
 network 10.0.0.0
 network 172.16.0.0
 network 192.168.0.0
!
ip route 0.0.0.0 0.0.0.0 192.168.1.1  #ROUTING TO R2-INTERNET

(more…)

Setup:

• Dual-homed BGP between AS100 and AS200
• AS100
  • HSRP 192.168.0.10 between R1 and R2
  • Router 1 HSRP Master
  • Linkstate tracking on Fa0/0
  • EIGRP as IGP
• AS200
  • HSRP 10.10.10.10 between R3 and R4
  • Router 3 as HSRP Master
  • Linkstate tracking on Fa0/0
  • OSPF for IGP

Scenario: The link between Router1 and Router3 would fail. Linkstate tracking would decrement the HSRP priority and switch masters.

When the link was restored and using default HSRP timers, the HSRP master would switch back before the BGP session was established between Router1 and Router3 (at least in GNS3).
Setting up delay timers and linkstate tracking would allow for a good recovery.

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Quality of Service Deployment

Choosing the correct WAN Type.

• WAN Providers, you get what you pay for.
  • Tried and True providers
• Don’t design a sinking ship, bandwidth.
• Determine bursting capabilities.
• QoS classes / Policies support.
• Multicast support.

Modular QoS CLI ( MQC )

• Class-map

R1(config)#class-map ccdp
Class-map configuration commands:
  description  Class-Map description
  exit         Exit from class-map configuration mode
  match        classification criteria
  no           Negate or set default values of a command

R1(config-cmap)#mat
R1(config-cmap)#match ?
  access-group         Access group
  any                  Any packets
  atm                  Match on ATM info
  class-map            Class map
  cos                  IEEE 802.1Q/ISL class of service/user priority values
  destination-address  Destination address
  discard-class        Discard behavior identifier
  dscp                 Match DSCP in IPv4 and IPv6 packets
  fr-de                Match on Frame-relay DE bit
  fr-dlci              Match on fr-dlci
  group-object         Match object-group
  input-interface      Select an input interface to match
  ip                   IP specific values
  mpls                 Multi Protocol Label Switching specific values
  not                  Negate this match result
  packet               Layer 3 Packet length
  precedence           Match Precedence in IPv4 and IPv6 packets
  protocol             Protocol
  qos-group            Qos-group
  source-address       Source address
  vlan                 VLANs to match

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What is QoS?

• http://docwiki.cisco.com/wiki/Quality_of_Service_Networking
• Quality of life insurance
• The ability to dictate traffic treatment
  
  • Prioritization.
    • Only happens with congestion.
  • Shaping / Policing.
    • Shaping: Mold the traffic down to a specific speed.
    • Policing: ‘evil’ traffic types ( p2p / video ).
  • Advanced Strategies ( WRED – Weighted random early detection)
    • Drop selective TCP streams so it won’t hit max.
• Strategies to fight the enemy
  • Delay ( how long it takes for a Packet A to get to the other side).
    
  • Jitter ( Delay variation, Times between Packets A,Packet B,and Packet C taking to get to the other side)
    
  • Packetloss
    

	Audio Requirements	Video Requirements
Jitter	< 30ms	< 30ms
Delay	< 150ms	< 150ms
Loss	< 1%	< 1%
QoS:	DSCP EF	DSCP AF41
Bandwith	Low	High

• https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus1000/sw/4_0/qos/configuration/guide/nexus1000v_qos/qos_6dscp_val.pdf

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