Ccnp Route

Front 1

Network Fundamentals

Back 1

-Frame Switching - L2

-Packet Switching - L3

-Three Types of packet switching:

-Process Switching (CPU = middle man)

-Fast Switching (caches flows, 1st is CPU)

-CEF (2 Tables:)

-FIB (L3 forwarding information)

-ADJ (L2 forwarding information)

Front 2

TCP Functions

Back 2

TCP Sliding window = Doubling of TCP segments for higher throughput (1, 2, 4, 8, etc.). This continues until the receiver doesn't ACK all segments. Or until maximum window size is reached.

Global Synchronization = When a routers output queue fills to capacity, all TCP flows start to drop packets, causing TCP slow start

WRED - Randomly drops packets to prevent Global Sync.

Front 3

UDP Functions

Back 3

Starvation = When UDP trumps TCP when there is congestion (because TCP throttles back)

Put TCP in separate queues

Front 4

EIGRP

Back 4

-Distance Vector

-IP Protocol 88

-Uses DUAL algorithm

-Lowest BW + sum of delays

-Multicast Address: 224.0.0.10

-3 tables (neighbor, topology, routing)

-Timers (LAN: Hello = 5 / Hold = 15)

-Timers (T1: Hello = 60 / Hold = 180)

-Maximum Paths (default = 4)

-Variance (default = 1)

Front 5

EIGRP neighbor requirements

Back 5

-Send/receive packets

-Primary IP in same subnet

-AS number

-K-values

-Authentication

-Cannot be passive interface

Front 6

EIGRP Messages

Back 6

-Hello -Neighborship

-Update -Topology Table Exchange

-ACK -Topology Table Exchange

-Query -Routes are lost

-Reply -Routes are lost

Front 7

EIGRP Percent Bandwidth

Back 7

-Only 50% of BW is used by default

-On multipoint interfaces (BW / # of PVCs)

-ip bandwidth-percent eigrp <%>

Front 8

EIGRP Metric Manipulation

Back 8

-Offset-list = Adds value to FD/RD

-(manipulates delay value)

Front 9

EIGRP Stub

Back 9

-router eigrp

-eigrp stub

-Limits the query Scope

Front 10

EIGRP Route Filtering

Back 10

-distribute-lists

-(filters routes into topology or to neighbors)

-Can call (route-maps, ACLs, Prefix-lists)

Front 11

Distribute List Logic

Back 11

-ACLs

-PERMIT = DO NOT FILTER

-DENY = FILTER ROUTE

-Prefix-List

-PERMIT = DO NOT FILTER

-DENT = FILTER ROUTE

-Route-map

-PERMIT = DO NOT FILTER

-DENY = FILTER

-ACLs in Route-maps

-PERMIT = TAKE ACTION

-DENY = MOVE TO NEXT ROUTE-MAP SEQ.

Front 12

Route Summarization (EIGRP)

Back 12

interface <GiX/X>

ip summary-address eigrp <AS#> <PREFIX> <MASK>

-When route summarization is configured it resets neighbors

-Router adds null0 to routing table to prevent loops

Front 13

EIGRP Default Router

Back 13

-Used to advertise 0.0.0.0/0 route

-Three ways to advertise:

-Static default route

-Configure a default network

-Use summary address (removes all other networks)

Front 14

Named EIGRP

Back 14

-router eigrp <NAME>

-address-family ipv4 autonomous-system <AS#>

-af-interface

-Used to configure:

-Passive interfaces

-Hello/Hold timers

-Summary Address

-Split Horizon

-topology base

-Used to configure

-Distribute-lists

-Variance

-Redistribution

Front 15

OSPF

Back 15

-Link State

-IP Protocol 89

-Uses Dijkstra algorithm

-Metric is cost (REFERENCE / BW)

-Multicast Address (224:0.0.5 = all RTRs / .6 = DR)

-OSPF Database (neighbors, topology, route)

-Timers (BC/P2P: Hello = 10 / Hold = 40)

-Timers (nBC/P2MP: Hello = 10 / Hold = 40)

-Maximum Paths (default = 4)

-Periodic Reflooding (30 minutes)

Front 16

OSPF Database (LSAs)

Back 16

Type 1 = Router LSA (INTRA AREA)

Type 2 = Network LSA (INTRA AREA)

Type 3 = Summary LSA (INTER AREA)

Type 4 = ASBR Summary LSA (INTER AREA)

Type 5 = External (ASBR) LSA (Redistribution)

Type 7 = NSSA External

-----------------------------------------------------------

OSPFv3 LSAs

-----------------------------------------------------------

Type 8 = Link LSA (Link local address + global)

Type 9 = Intra-Area-Prefix-LSA (carried prefixes)

Front 17

OSPF Neighbor Requirements

Back 17

-Hello Interval

-Dead Interval

-Area ID

-Subnet Mask

-Stub Area Flag

-Authentication

Front 18

OSPF Network Types

Back 18

Front 19

OSPF Neighbor States

Back 19

Down

Attempt -Static Neighbors

Init. -Received HELLO from nbr.

2-Way -RTR B responds (I KNOW YOU)

ExStart -First DBD from LSA header

-Master/Slave election (^ R-ID)

-DR Multicast Traffic

Exchange -Detailed DBDs (until = LSIDs)

Loading -Any missing LSAs?

(received LSR, sending LSU)

Full -LSAs sent,received, acked, & adj.

---------------------------------------------------------------------

SPF Calc. -Each RTR calculates own paths

Front 20

OSPF Route Preference

Back 20

Intra-area

Inter-area

External

Front 21

OSPF Route Filtering

Back 21

-Filtering done on ABRs

-Area <#> filter-list prefix <NAME> in/out

-IN = Filter prefixes INTO the configured area

-OUT = Filter prefixes OUT of configured area

Front 22

OSPF Route Filtering

(BLOCKING in the routing table)

Back 22

-Can create traffic black holes

-ONLY WORKS IN "IN" direction

-distribute-list prefix <NAME> in

Front 23

OSPF Route Summarization

Back 23

-Only can be done on ABRs/ASBRs

area <#> range <IP ADDRESS> <MASK> <COST>

Front 24

OSPF ASBR Summarization

(on redistributed routes)

Back 24

summary-address <PREFIX> <MASK>

Front 25

OSPF Default Routing

Back 25

-Have to have default route, unless using the 'always' sub-command

default-information originate <always> <metric XXX> <metric-type 1|2> <route-map>

Front 26

OSPF Stub area Default Routing Cost Change

Back 26

-Allows intra-area stub routers to use default routes for forwarding packets to ABRs

area <X> default-cost <XXX>

Front 27

OSPF Stub area Types

Back 27

-Stub (Filters Type 5 LSAs)

-Totally Stubby (Filters Type 3/4/5 LSAs)

-NSSA (Filters Type 5, allows red.)

-Totally NSSA (Filters Type 3/4/5, allows red.)

Stub config:

area <X> stub

Totally stubby config:

area <X> stub no-summary (ONLY ON ABRs)

area <X> stub (ON INTRA RTRs.)

NSSA config:

area <X> nssa

Totally NSSA config:

area <X> nssa no-summary (ONLY ON ABRs)

area <X> nssa (ON INTRA RTRs.)

To inject default route into NSSA (ON ABR):

area <x> nssa default-information-originate

Front 28

OSPF ASBR External route filtering

Back 28

-ONLY USE "OUT" IN DISTRIBUTE-LIST

distribute-list prefix <NAME> out <EIGRP/CONN.>

Front 29

OSPF Virtual Links

Back 29

area <TRANSIT AREA> virtual-link <ROUTER-ID of Area 0 RTR>

Virtual-link authentication:

area <#> virtual-link <R-ID> authentication null

area <#> virtual-link authentication-key <#>

area<#> virtual-link authentication message-digestmessage-digest-key <#> md5 <PW>

Front 30

OSPF Path Manipulation

Back 30

-Change Metric

-Route Summarization on ABR

-Filtering on ABR

-Changing metric-type on ASBR

Within an area:

-auto-cost reference BW

-interface bandwidth

-change OSPF cost at interface level

ABR Preference:

-Summarization

-Filtering

ASBR Preference

-Metric Type

-default cost (default information originate)

Front 31

Redistribution

Back 31

-SEED METRIC (RIP = hops, EIGRP = K-values)

EIGRP into OSPF:

redistribute EIGRP 100 subnets

OSPF into EIGRP

redistribute OSPF 1 metric <BW> <DLY> <RELI> <LOAD> <MTU>

Front 32

Route-maps

Back 32

You can match against:

-interface

-ip address

-ip next-hop

-ip route-source

-metric

-route-type

-tag

You can set:

-metric <value> | <A B C D E>

-metric-type

-tag

Verification:

show route-map

show ip access-list

Front 33

Administrative Distance

Back 33

EIGRP:

distance eigrp <INTERNAL> <EXTERNAL>

EIGRP INTERNAL ONLY:

distance <X> <IP SCR> <WLD MASK>

OSPF:

distance ospf <EXTERNAL AD> <INTRA-AREA> <INTER-AREA>

distance <VALUE> <R-ID> <0.0.0.0>

Front 34

Path manipulation with Redistribution

Back 34

-Changing metric values while redistributing

-Changing metric-types

-Route Filtering

-Route Summarization

Front 35

IP SLA / PBR Configuration

Back 35

ip sla 1

icmp echo 8.8.8.8 source-interface gi0/1

frequency 1

ip sla schedule 1 start-time now life forever

!

track 1 ip sla 1

delay down 1 up 1

!

route-map PBR permit 10

match ip address <XXX>

set ip next-hop verify-availability next-hop-ip 1 track 1

!

interface Gi0/0

ip policy route-map PBR

------------------------------------------------------------------

show ip sla configuration

show ip sla statistics

show track

debug ip policy

traceroute x.x.x.x source y.y.y.y

Front 36

PBR Set options

Back 36

Four set options:

-next hop ip

-default next hop ip

-interface

-default interface

PBR PROCESS DOES NOT PERFORM LOCALLY GENERATED PACKETS:

ip local policy route-map <NAME>

Front 37

NTP

Back 37

NTP Clients poll NTP servers for date/time

Stratum 1 = Directly connected to atomic clock

Stratum 2 = 1 hop away

Stratum 3 = 2 hops away

Stratum 4 = 3 hops away

NTP Server Configuration:

clock set <HH:MM:SS> <DATE MONTH YEAR>

ntp master

ntp peer <x.x.x.x>

!

interface Gi0/0

ntp broadcast

!

ntp authentication-key <#> md5 <PASSWORD>

ntp-trusted-key <#>

Ntp authenticate

NTP Client Configuration:

ntp server <X.X.X.X>

ntp broadcast client

!

ntp authentication-key <#> md5 <PASS>

ntp trusted-key <#>

ntp authenticate

ntp server <X.X.X.X> key <#>

------------------------------------------------------------------

show ntp status

Front 38

BGP

Back 38

-Path Vector

-TCP 179

-Uses Path Attributes for metric

-eBGP/iBGP neighbors

-Public AS# Range: 1-64495

-Private AS# Range: 65512 - 65534

-Static Neighbors

Front 39

BGP Update Source/ ebgp multihop

Back 39

Update Source:

-Used for loopback for additional redundancy (not link dependent)

neighbor <X.X.X.X> update-source <LOOPBACK>

eBGP multihop:

-eBGP is set to 1 hop, and loopbacks are more than 1 hop away

neighbor <X.X.X.X> ebgp-multihop

Front 40

BGP Neighbor States

Back 40

-IDLE -BGP process admin down/retry

-Connect -Waiting for TCP connection to be completed

-Active -TCP connection failed, connect-retry running

-Opensent -TCP connection exists, sent BGP open mssg, waiting

-Openconfirm -Open mssg sent and received from neighbor

-Established -Neighbor param. match, peers can now exch. updates

Front 41

BGP Open Message

Back 41

-Used in neighbor establishment

-Type 1

-BGP values & capabilities are exchanges

-Contains:

-Version

-AS#

-Hold-time

-Router-ID

-Optional Parameters length

-BGP Capabilities

Front 42

BGP Update Message

Back 42

-Includes: withdrawn, changes, and new routes

-Used to exchange PAs and the prefix/length (NLRI)

-Type 2

-Contains:

-Unfeasbile routes length

-Withdrawn routes

-Total path attributes length

-Path Attributes (TLV - Type length value)

-NLRI Prefix

-NLRI Prefix Length

Front 43

BGP Notification Message

Back 43

-Used to signal a BGP error (neighbor relations)

-Type 3

Contains:

-Error code

-Error subcode

-Data

Front 44

BGP Keepalive Message

Back 44

-Maintains neighborship

-Type 4

-No Data

Front 45

BGP AS_PATH Attribute

Back 45

-BGP uses AS_PATH by default for choosing the best route

-AS_SEQ (Sequence of AS Paths 10.0.0.0/24 5 6 7 i)

-AS_SET (Sequence of AS Paths for a route summary ( 5 {1 2 3} )

Front 46

Injecting routes into BGP

Back 46

-Network command

network <X.X.X.X> mask <Y.Y.Y.Y>

-Redistribution

redistribute connected

-Route Summarization

aggregate-address <PREFIX> <LENGTH>

*to use route-summarization, you need a subset installed in the routing table

Front 47

BGP Status Codes

Back 47

* = Valid Path

> = Beth Path

i = learned via iBGP

R = RIB Failure

-already in my routing table as a lower dist.

-maximum size limit on routing table

-memory failure

0.0.0.0 (next hop) = I own this route

Front 48

BGP advertising rules

Back 48

-ONLY ADVERTISE BEST ROUTE

-Do not advertise iBGP learned routes to iBGP peers

-iBGP routers do not update next-hop to iBGP peers

neighbor <X.X.X.X> next-hop-self

Front 49

BGP Filtering

Back 49

-Distribute-lists

-IN = PREVENT UPDATES ENTERING BGP TABLE

-OUT = PREVENT BEST BGP ROUTE ADVERTISED

-filter-lists

-route-maps

Common uses for BGP filtering:

-prevent becoming a transit network

Front 50

Clearing BGP neighbors

Back 50

-You can clear BGP neighbors without resetting neighborship

neighbor <X.X.X.X> soft-reconfiguration inbound

clear ip bgp 1.1.1.1 soft in

-or-

This doesn't require configuration

clear ip bgp 1.1.1.1 in

clear ip bgp 1.1.1.1 out

Front 51

BGP Path Attributes

Back 51

Now We Love Oranges AS Oranges Mean Pure Refreshment

-Next-hop reach.

-Weight

-OUTBOUND (LOCAL) (HIGHER IS BEST)

neighbor <IP> weight 100

-Local Pref

-OUTBOUND (LOCAL TO AS) (HIGHEST IS BEST)

bgp default local-preference <XXXX> (or use a route-map)

-Originate

-(Prefer network & redistributed over summary)

-AS_Path

-INBOUND (set as-path in route-map)

-Origin

-Origin Codes (IGP > EGP > ?)

-MED

-INBOUND (local to AS only) (set metric in route-map)

-bgp <x> always-compare-med

-Paths

-(eBGP > iBGP)

----------------------------------------------

Three Tie breakers:

Oldest BGP route

Lowest neighbor BGP RID

Lowest Neighbor IP Address

Front 52

BGP Address Family

Back 52

MP-BGP

-IPv4 Unicast

-IPv4 Multicast

-IPv6 Unicast

-VPNv4 Routes (MPLS VPN)

By default BGP only advertises IPv4.

Three options for configuration:

-Dual BGP Sessions

-Single BGP IPv4

-Single BGP IPv6

Front 53

RIPng (IPv6)

Back 53

-AD 120

-UDP 521 (NG) 520 (v2)

-Multicast address: FF02::9

-Link local next-hops

-RIP NAME PROCESSES DO NOT HAVE TO MATCH

---------------------------------------------------------------------

ipv6 unicast-routing

ipv6 router rip <NAME>

!

interface <Gi0/0>

ipv6 rip <NAME> enable interface

Front 54

EIGRPv6

Back 54

-Multicast address: FF02::A

-Link Local next hop IP address

--------------------------------------------------------------

ipv6 unicast-routing

ipv6 router eigrp <#>

eigrp router-id <X.X.X.X>

no shutdown

!

interface <Gi0/0>

ipv6 eigrp 100

Front 55

OSPFv3

Back 55

-IPv6 OSPF supports multiple instances

-Type 8 LSA - Link LSA (link local + global)

-Type 9 LSA - Intra-area-prefix-lsa (prefix info.)

-----------------------------------------------------------------

ipv6 unicast-routing

ipv6 router ospf <#>

router-id <X.X.X.X>

!

interface <Gi0/0>

ipv6 ospf <#> area <X>

Front 56

IPv6

Back 56

IPv6 Static route:

IPv6 route 2111:1111::/64 [LL/Gbl Next hop]

*you need to specify interface w/ LL

IPv6 Access-list configuration:

ipv6 access-list test

permit TCP any 2001:AAAA::/64 eq telnet

!

interface Gi0/0

ipv6 traffic-filter test in

Front 57

IPv4 & IPv6 coexistence

Back 57

-Dual Stack (hosts/RTRs use both IPv4/v6)

-Tunneling (P2P, Multipoint)

-NAT-PT (nat protocol translator)

-MCT

-manual tunnels (IP: 41)

-GRE

-default tunnel

-6to4 (IP: 2002)

-dynamic multipoint tunnel

-2nd/3rd quartets to store IPv4 address

-ISATAP

-dynamic multipoint tunnel

-easily supports global unicasts

-7th/8th quartets to store IPv4 address

Front 58

MCT/GRE Configuration

Back 58

MCT Configuration:

interface Tunnel 0

ipv6 address 2001::1/64

tunnel source gi0/0

tunnel mode ipv6ip

tunnel destination 192.168.0.1

!

ip route 0.0.0.0 0.0.0.0 tunnel 0

----------------------------------------------------------

GRE Configuration:

tunnel mode gre ip

---------------------------------------------------------

show interface tunnel

show ipv6 interface brief

debug tunnel

Front 59

6to4 tunnel configuration

Back 59

-DOES NOT SUPPORT IGPs

-Two options for addressing:

-Embed IPv4 into IPv6 behind 2002 prefix

-Use a global prefix to people in the cloud

------------------------------------------------------------------

interface tunnel 0

ipv6 address 2002:0101:0101::1/64

tunnel source ser0/0

tunnel mode ipv6ip 6to4

!

ipv6 route 2002::/16 tunnel 0

------------------------------------------------------------------

option 2:

ipv6 route 2001:eeee::/48 tunnel 0 <2002:120b:120b::11>

Front 60

ISATAP tunnel configuration

Back 60

-Client must be dual-stacked

-Designed for transporting IPv6 within a site

-Can use any IPv6 (/64) prefix

-64-bit interface identifier

-First 32 bits contain 0000:5EFE

-Remaining 32 bits encode the IP address

Sample Host IPv6 Address:

FE80::0000:5EFE:3211:FFFE:11

-----------------------------------------------------------------

interface tunnel 0

ipv6 address 2001:1111:2222:aaaa::/64 eui-64

no ipv6 nd suppress-ra

tunnel source 30.1.1.1

tunnel mode ipv6ip isatap

interface ser0/0

ip address 30.1.1.1 255.255.255.0

IF 6to4 = 2002 prefix

IF ISATAP = 0000:5efe

Front 61

NAT64 / DNS64

Back 61

NAT64:

-Allows IPv6 hosts to access IPv4 content

-V6 -> V4 connections

-Stateful = Any IPv6 address (keeps NAT info)

-Stateless = Restricted to certain IPv6 address

-SPECIFIC PREFIXES NEEDED:

-Well known = 64:ff9b::/96

-NSP = derived from global IPv6 prefix

DNS64:

-Allows IPv6 host to resolve requested IPv4

-Looks for A record, and sends it back AAAA

-----------------------------------------------------

Stateless NAT64 Configuration:

interface Gi0/0

nat64 enable

!

interface Gi0/1

nat64 enable

nat64 prefix stateless 2001::/64

nat64 route 2.2.0.0/16 fa0/0

Stateful NAT64 Configuration:

nat64 prefix stateful 2001::/64

nat64 v4 pool INE 2.2.3.2 2.2.3.20

nat64 v6v4 list test pool INE overload

Front 62

VPN/IPsec

Back 62

-Peer-to-Peer VPN: (peering with ISP)

-Overlay VPN: Peers are your own routers

IPsec:

-Confidentiality

-Integrity

-Authentication

-Anti-replay

SA = Secure Association (Tunnel)

IKE = Internet Key Exhange

Phase 1 = ISAKMP Session (transform sets)

Phase 2 = SA associations

Transport mode = used for RA VPN

Tunnel Mode = used for S2S VPN

Front 63

VRF

Back 63

-Creates Separate Routing table

----------------------------------------------------------

ip VRF <NAME>

!

interface Gi0/0

ip vrf forwarding <NAME>

!

ip route vrf <NAME> <PREFIX> <SUBNET> <NH>

-----------------------------------------

show ip vrf

show ip vrf interfaces

show ip route vrf

show ip protocols vrf

Front 64

DMVPN

Back 64

Point to multipoint L3 overlay VPN (hub & spoke)

DMVPN uses:

-Multipoint GRE (mGRE)

-Next Hop Resolution Protocol (NHRP)

-IPsec Crypto Profiles

-Routing

-----------------------------------------------------------------

Point to Point GRE:

interface tunnel 0

ip address 10.1.3.1 255.255.255.0

tunnel source loopback 0

tunnel destination 3.3.3.2

Multipoint GRE:

interface tunnel 0

ip address 10.1.3.1 255.255.255.0

tunnel source loopback 0

tunnel mode gre multipoint

Front 65

IPv6 Client Addressing Options

Back 65

Front 66

PPP

Back 66

-Two authentication methods: PAP/CHAP (secure)

username R2 password secret

!

interface ser0/0

encapsulation ppp

ppp authentication chap

ppp chap hostname <name>

Front 67

PPPoE

Back 67

-Primarily used for DSL

-Uses dialer interfaces on the client side

-MTU needs to be lowered to 1492

pppoe enable

pppoe-client dial-pool-number 1

!

interface dialer 1

mtu 1492

ip address negotiated

encapsulation ppp

dialer pool 1

ppp chap password 0 cisco

!

interface fa0/0

pppoe-client dial-pool-number 1