Руслан Савченко, инструктор онлайн-школы SkillFactory – о самом интересном из программы курсов CCNP Route и CCNP Switch от Cisco и о том, какие знания в области маршрутизации и коммутации нужно иметь, чтобы решать по-настоящему сложные задачи.

1. 5 продвинутых технологий
Cisco, которые нужно знать
Ruslan Savchenko
09.08.2013
rsavchenko@getccna.ru
ведущий:

2. #
CCNP is:
 Routing: EIGRP, OSPF, RIP, BGP
 Switching
 Routing and switching troubleshooting
CCNP is NOT:
 Voice
 Wireless
 Security
 Specific WAN protocols (MPLS,
advanced BGP)
What Is CCNP-R&S Coverage

3. #
 CCENT: install and verify basic IP network
with supervision
 CCNA: also… configure and maintain a
multisite enterprise network, as directed
 CCNP: also… plan and troubleshoot
enterprise networks with advanced
solutions, collaborating with network
specialists
 CCIE: also… independently troubleshoot
and optimize network performance in
complex and integrated enterprise
networks
Certification for Network Engineers

4. #
Cisco Career Certifications

5. #
Switching (SWITCH)

6. #
SWITCH is:
 Campus layer 2 management (VLANs, STP –all flavors)
 Campus layer 3 management (Inter-VLAN Routing, first hop
redundancy)
 Campus network management (network design, security,
voice)
SWITCH is NOT:
 “Only layer 2”
 Deep wireless, security or voice
What Is Switch Coverage

7. #
Enterprise Campus Architecture

8. #
VLAN Deployment
 End-to-end VLANs
Users are grouped into VLANs
independent of physical location
If users are moved within the campus,
their VLAN membership remains the
same
 Local VLANs
Recommended solution in the
enterprise campus architecture
Users are grouped into VLANs
depending of physical location
If users are moved within the campus,
their VLAN membership changes

9. #
Trunk Configuration
 Configure VLANs
 Disable trunk negotiation
 Configure trunk mode
 Set native VLAN to unused VLAN
 Allow only required VLANs on trunks

10. #
Common Trunk Link Problems
 Trunks can be configured statically or autonegotiated with DTP
 For trunking to be autonegotiated, the switches must be in the same
VTP domain
 Some trunk configuration combinations will successfully configure a
trunk, some will not

11. #
Issues with 802.1Q Native VLAN
 Native VLAN frames are carried over the trunk link untagged
 Native VLAN must match at the ends of a trunk
 A native VLAN mismatch will merge traffic between VLANs
 Default native VLAN is VLAN 1
 Configure an unused VLAN as native VLAN on trunks

12. #
Spanning Tree Standards
 802.1D-1998: The legacy standard for bridging and STP
 CST: Assumes one spanning-tree instance for the entire bridged
network, regardless of the number of VLANs
 PVST+:A Cisco enhancement of STP that provides a separate 802.1D
spanning tree instance for each VLAN configured in the network
 802.1D-2004: An updated bridging and STP standard
 802.1s (MST):Maps multiple VLANs into the same spanning-tree
instance
 802.1w (RSTP):Improves convergence over 1998 STP by adding roles to
ports and enhancing BPDU exchanges
 PVRST+: A Cisco enhancement of RSTP using PVST+

13. #
Spanning Tree Recommendations
 Use PVRST+ or MSTP for best
convergence
 Take advantage of the Cisco
STP toolkit
 Keep STP domain as simple as
possible
 Do not disable STP—it
protects against unplanned
loops
 Use routed links if possible

14. #
Cisco STP Toolkit
 PortFast: configures access port as edge
ports which transition directly to
forwarding state
 BPDUGuard: disables a PortFast-enabled
port if a BPDU is received
 BPDUfilter: suppresses BPDUs on ports
(not recommended)
 RootGuard: prevents external switches
from becoming roots
 LoopGuard: prevents an alternate port
or root port from becoming the
designated port if no BPDUs are received
 UplinkFast*: provides from 3 to 5
seconds convergence after link failure
 BackboneFast*: cuts the convergence
time by max_age for an indirect failure

15. #
Process switching
Slowest method—every packet examined by CPU, all forwarding decisions
made in software
Fast switching (route caching)
Faster method—first packet in each flow examined by CPU, forwarding
decision cached in hardware for subsequent packets in flow
Cisco Express Forwarding (topology-based switching)
Fastest method—hardware forwarding table created regardless of traffic
flows, all packets switched using hardware
Switching mode for multi-layer switches
Cisco Layer 3 Switching Methods

16. #
Configure SVI and Routed Interface
switch(config)# ip routing
switch(config)# interface vlan10
switch(config-if)# ip address 10.1.10.1 255.255.255.0
switch(config-if)# no shutdown
switch(config)# interface vlan20
switch(config-if)# ip address 10.1.20.1 255.255.255.0
switch(config-if)# no shutdown

17. #
HSRP Configuration

18. #
HSRP and Spanning Tree
 Configured active
router should be the
same as STP root
bridge
 Blocked uplink caused
traffic to take less than
optimal path

19. #
GLBP Operation

20. #
GLBP Weights and Decrements

21. #
GLBP Configuration

22. #
Routing (ROUTE)

23. #
ROUTE is:
 IGP Routing: EIGRP, OSPF, RIP
 Path control: route maps, filters, redistribution, policy-based
routing
 ISP connection management: standard BGP
 IPv6
 Branch offices and remote workers connectivity: VPN, GRE
ROUTE is NOT:
 Voice
 Wireless
 Security
 Specific WAN protocols (MPLS, IS-IS, advanced BGP)
 Multicast
What Is Route Coverage

24. #
Example: Enterprise network

25. #
Routing Protocol Comparison

26. #
OSPF. Link-State Protocols

27. #
Link-state routing requires a hierarchical network structure:
Transit area (backbone or area 0)
Normal areas (non-backbone areas)
Area Terminology and Router Types
ABR:Area Border Router
ASBR:Autonomous System Boundary Router
R5, R6:Internal routers
R1:Backbone router

28. #
OSPF Packet Types

29. #
Example of Different LSAs

30. #
Types of Areas

31. #
Design Limitations of OSPF
 If more than one area is configured, one of these areas has be
to be area 0—backbone area
 All areas must be connected to area 0
 Area 0 must be contiguous

32. #
No Direct Physical Connection to Area 0
 Area 20 added with no physical access to area 0
 A virtual link provides logical path to the backbone
 The OSPF database treats the link between routers ABR1 and
ABR2 as a direct link

33. #
Discontinuous Area 0
 Two companies merge without a direct link between them
 Virtual links are used to connect a discontinuous area 0
 A logical link is built between routers ABR1 and ABR2
 Virtual links are recommended for backup or temporary
connections too

34. #
EIGRP Capabilities and Attributes
 Advanced distance vector
 Multicast and Unicast instead of broadcast address
 Support for multiple network-layer protocols
 100% loop-free classless routing
 Fast convergence
 Partial updates
 Flexible network design

35. #
EIGRP Capabilities and Attributes
 Support for VLSM and discontinuous subnets
 Provides load balancing across equal-and unequal-cost
pathways
 Easy configuration for WANs and LANs
 Manual summarization at any point
 Sophisticated metric

36. #
Example: EIGRP Tables

37. #
Successor and Feasible Successor

38. #
Example: Successor and Feasible
Successor Solve Loop Issue
R1 receives information about the 10.0.0./8 from R8 and R4
FD on R1 is smaller than AD from R4 and the update from R4 is not FS

39. #
Verifying EIGRP Neighbors

40. #
Factors that Influence EIGRP Scalability
 Amount of routing information exchanged between peers
 Number of routers
 Depth of topology—the number of hops that information must
travel to reach all routers
 Number of alternate paths through the network

41. #
EIGRP Query Process Stuck-in-Active
The router must get replies to all its queries for a lost route to start calculating successor
information
If any reply to the query is lost or missing within three minutes:
 The route is SIA
 The router resets the neighbor relationship with the neighbor that fails to reply

42. #
Enterprise Network to ISP Connection
Options
 Single-homed
 Dual-homed
 Multihomed
 Dual-multihomed

43. #
BGP Routing Between Autonomous
Systems
 BGP is to provide an interdomain routing system
 BGP guarantees the exchange of loop-free routing information
 BGP works differently than IGPs
 BGP is a policy-based routing protocol
 Control traffic flow using multiple BGP path attributes

44. #
Basic EBGP Configuration

45. #
BGP Path Selection Decision Process
Consider only (synchronized) routes with no AS loops and a
valid next hop, and next steps for evaluation are:

46. #
Set AS Path with Route Map

47. #
Redistribution Techniques

48. #
Two-Way Multipoint Redistribution
Issue

49. #
Questions?

50. #
Thank you!