NAT

IP NAT configuration

1. IP NAT inside interface 
2. IP NAT outside  interface
3. ip nat statements
4. access list

ip nat pool mypool 198.181.18.15 198.181.18.10 netmask 255.255.255.248

access-list 1 permit 192.16.10.32 0.0.0.15

ip nat inside source list 1 pool mypool overload

SPAN

Switch port monitor analyzer SPAN
monitor traffic on specific port, or port mirroring

R1(config)#monitor session 1 source interface fastEthernet 0
R1(config)#monitor session 1 source interface fastEthernet 1

IPv4 & IPv6 Addressing

Great comparing between IPv4 and IPv6



IPv4 address
32-bit
4 Octets
8 bit an octet (8bits.8bits.8bits.8bits) = 32
8bits  = 1 byte
1 byte.1 byte.1 byte.1 byte = 4 bytes

IP Classes
Class A 1 - 126       /8
Class B 128 - 191   /16
Class C 192 - 223   /24
Class D 224 - 239 unicast and multicast
Class E 240 - 256

8 bit representation

128   64   32   16   8    4    2    1 



IPv6 shortcuts

0004:0000:0000:0000:0000:00FD:000C:0082

Every 4 Zeros can be 1 Zero

0004:0:0:0:0:00FD:000C:0082

Leading Zeros can be removed

4:0:0:0:0:FD:C:82

Double colon can be used to eliminate similar spaces 

4::FD:C82

Max 1 time Double Colon

::

BB::1

LLA   FE80 
Link Local Address (which is similar APIPA for ipv4 )

Stateless (autoconfigure)

11:22:33:44::/64
IPv6 subnet mask
the first 64 bits is Network prefix the remaining is Client or user Prefix or ID

how to determine your subnet mask
1- figure out how many users IDs need 
example : 14 users 
how many bits give 14 ?
2^4=16 

4 - 128 bits = 124 is the mask needed for 12 client IDs

11:22:33:44::/124


Auto Configure works?
it a new feature for ipv6 which creates a unique IPv6 address by utilizing the existing 48bit MAC address for physical NIC with insertion of FFFE in the middle of the MAC address

Statefull (DHCPv6)

SSH

Secure Shell or Secure Socket Shell, is a UNIX based command interface and protocol for securely getting access to a remote computer.
SSH is a suite of three utilities (slogin, ssh and scp)  are encrypted and secured, both ends of client/server connection are authenticated using a digital certificate.
SSH uses RSA public key cryptography for both connection and authentication. Encryption algorithms include Blowfish, DES, and IDEA
IDEA is default algorithm
SSH2 is the latest version, proposed by IETF

SSH uses port 22

Basic SSH configuration for cisco router
create user name and password

1- R2(config)#username cisco password cisco

2- Create domain-name
R2(config)#ip domain-name SSH-lAB

3- Generate Certificate
R2(config)#crypto key generate rsa
The name for the keys will be: R2.SSH-lAB
Choose the size of the key modulus in the range of 360 to 2048 for your
  General Purpose Keys. Choosing a key modulus greater than 512 may take
  a few minutes.

How many bits in the modulus [512]: 512
% Generating 512 bit RSA keys ...[OK]

R2(config)#
*Mar  1 00:33:04.371: %SSH-5-ENABLED: SSH 1.5 has been enabled

4- Apply SSH to interface or VTY
R2(config-line)# login local
R2(config-line)#transport input ssh


R1#ssh -l cisco 192.168.10.2
Password: 
R2>ena
Password: 
R2#

R1#show crypto key mypubkey rsa
% Key pair was generated at: 00:14:35 UTC Mar 1 1993
Key name: R1.SSH-LAB
 Usage: General Purpose Key
 Key is not exportable.
 Key Data:
  305C300D 06092A86 4886F70D 01010105 00034B00 30480241 00A845F2 99A0B9D0
  B663F008 435F3C6A AF7F53D7 9CDEB6B9 3389F2D2 EB5852D7 DB21FAA7 8D9BA489
  CA71E6C5 BD00087D BBE2C833 C8172E57 58E1A6F3 BC58A5F2 91020301 0001
% Key pair was generated at: 00:14:37 UTC Mar 1 1993
Key name: R1.SSH-LAB.server
 Usage: Encryption Key
 Key is not exportable.
 Key Data:
  307C300D 06092A86 4886F70D 01010105 00036B00 30680261 00B0CA71 FC7EF3BC
  702FBE93 5CCAA2E9 866F5642 3FD3E12B 566BF63A 72967FF7 BE73EBA5 1DC109A8
  F544DA83 87B938DD 61D0FECE 55ACBD86 2FEAF66A 9E5526C8 2E53B9D5 63814B6B
  5D3F8F72 ECAA8FA8 952DC75F 2F21C857 FB4358C4 9287F907 B1020301 0001

WAN Technologies

WAN connection types

• DSL modem 
• Cable modem
• Satellite
• Wireless 4G LTE/ Wimax
• T1 Lines
• Fiber

More bandwidth gain

Metro Ethernet (MAN) based on ethernet used fiber optics to connect buildings together 

Easily connects with LAN

less expensive 

Synchronous Optical network (SONET): a fiber optic multiplexing standard that allows multiple channels of  communication to share a fiber optic cable

Metro Ethernet typical speeds 10 Gbps, 40 Gbps, 100Gbps

Metro ethernet is a way we coule interconnect sites within single metropolitan area network

-VSAT: very Small Aperture Terminal (VSAT)

A WAN Technology that uses small satellite dishes instead at network locations for two-communications via a satellite.

VSAT Characteristics:

• Two way satellite communication
• Satellite dish is less than 3 meters
• Useful for locations that can't have a wired connection 
• Data rates typically in the range of 56Kbps - 4 Mbps
• Data experiences more delay
• Sensitive to weather condition 

Cellular 3G/4G

G: stands for Generation

standards defined by the international  telecommunications union  radiocommunication sector

LTE Long Time Evolution is commonly offered as 4G technology

MPLS:

Multi-protocol label switching 

Makes forwarding decision based on a 20-bit label in a 32-bit header

The idea behind MPLS ( instead of having routers forward traffic based on destination IP address found in layer 3 header of a packet, we can assign labels to packets and routers within MPLS could can make forwarding decision based on label instead of ip address.

Routing based on a label rather than an ip address was originally viewed to be much more efficient way of forwarding traffic within a cloud

other advantages for MPLS 

• services provider can isolate customers traffic based on different labels 
• advance traffic engineering  that gives us a fine level of control as of how traffic is going flow through our the network
• quality of service (QoS) we can treat different types of traffic differently
•  MPLS ability to be compatible with multiple protocols

How MPLS labeling works

MPLS is going to injects its 32-bit header in between L2 and L3 headers and inside that 32-bit header we have 20-bit label (that is the label the routers look at to make its forwarding decision)

different devices on the MPLS network are going to play different rules

CPE (Customer Premise Equiment) a device at customers site that connects to an MPLS provider, ELSR (Edge label Switch Router) a device at the edge of an MPLS cloud that adds lables to traffic coming into the cloud and removes labels from the traffic leaving the cloud (note: an ELSR also know as a PE (provider edge router), LSR (Label Switch Router) a device inside an MPLS cloud that relables traffic and makes forwarding decisions based on those labels (note: an LSR is also know as P Provider Router)

its important to understand that, a packet does not keep its label thoughout the MPLS cloud every LSR hop is going to change the label  

Leased Line T1, E1 T3 and E3 Circuits

Typically, a point-to-point connection that interconnects two sites and provides dedicated bandwidth to the subscribers 

Frame Relay

Frame Relay: 
A layer 2 WAN technology that sends frames over virtual circuits (VCs) that are identified by (DLCI) Data Link Connection Identifier number.

Virtual Circuit (VC): a logical connection between two ends.

Switched Virtual Circuits (SVC) 
A virtual circuit that is brought up on an as-needed basis

Permanent Virtual Circuit (PVC)
A virtual circuit that is always active

Data-Link Connection Identifier (DLCI)
A locally siginificant number that identifies a virtual circuit (VC)

Point-to-Point Circuit
A single VC interconnecting two endpoints, where both endpoints belong to the same IP subnet

Point-to-Multipoint Circuit
A connection from one end to one or more other endpoints, where all end points belong to the same IP subnet

Service Level Agreement
An agreement between a service provider and their customer, describing the level of  service the service provider guarantees  for a specific connection, which guarantee a minimum level of service

Committed Information Rate (CIR)
A bandwidth amount a service provider guarantees to be available, a certain percentage of the time, on a customer's virtual circuit.

Discard Eligibility (DE) bit
A bit in frame relay frame's header that indicates the frame was sent in excess of the CIR and can be discarded by the service provider if congestion is occurring

Backward Explicit Congestion Notification (BECN)
A bit in a frame relay frame's header used to tell a sender to slow down its transmission rate

Forward Explicit Congestion Notification (FECON)
A bit in a Frame relay frame's header used to tell a receiver to send a frame to the sender, which the service provider will mark with a BECN bit





























Frame_relay will be sending data over DLCI (Data Link connection Identifier) known as layer 2 addresses

Frame - LMI type
R3(config-if)#frame-relay lmi-type ?
cisco
ansi  
q933a

Configuring and verifying  Frame_Relay with GNS3

1. Frame_Switch(config)#frame-relay switching
2. Frame_Switch(config-if)#encapsulation frame-relay
3. Frame_Switch(config-if)#frame-relay intf-type dce 
4. Frame_Switch(config-if)#frame-relay route 102 interface serial 1/1 201
5. Frame_Switch(config-if)#frame-relay route 103 interface serial 1/2 301

1. R1(config-if)#encapsulation frame-relay
2. R1(config-if)#ip address 10.1.1.1 255.255.255.0
3. R1(config-if)#no shut

the same config goes for R2 and R3 

Frame_Switch(config-if)#frame-relay route 102 interface serial 1/1 201

frame-relay                  Set frame relay parameter

route                            frame relay route for pvc switching

<16-1007>                  input dlci to be switched

interface                      outgoing interface for pvc switching

<16-1007>                  output dlci to use when switching

PPP

Serial Port - CSU/DSU A digital modem can a router's serial port to a service provider

Connector types:

• V.35 connector: supports speed of 2.048 Mbps using a rectangular connector 
• DB-60 connector: a 60-pin (also know as a cisco 5-in-1 connector) that is supported on serveral cisco router models)
• Smart Serial connector: a high-desnity connector that allows a WAN interface card (WIC) to have two serial connections instead of just one.
• EIA/TIA-232 connector: a 25-pin D-connector that supports of 64 kbps for short distance 

What protocol is running at layer 2?

HDLC (High level Data Link Control) the default layer 2 protocol used by cisco routers on serial interfaces

Note: cisco uses their own proprietary version of HDLC

DCE connector:  Data Communication Equipment DCE ( the end of a serial cable that provides clocking)

DTE connector: Data Terminal Equipment (the end of a serial cable that receive the clocking)

PPP (Point-to-Point) protocol 

a layer 2 encapsulation commonly used on leased lines, which supports authentications, compression, error detection and correction, and logical multi-link interface 

LCP (link control protocol)

a protocol used by PPP to setup, maintain, and teardown a connection

NCP (network control protocol) the protocols used to negotiate the configuration of protocols being transmitted over PPP link

Setup Serial connection with PPP 

1. Change encapsulations to PPP
2. Setup PAP authentication (username & password )
3. setup chap authentication 
4. traffic compress stac
5. reliable-link
6. Multi-link 

R1(config-if)#encapsulation ppp

R2(config-if)#encapsulation ppp

One Way authentication ( server - client authentication)

R1(config)#username papuser password pappassword

R1(config-if)#ppp authentication pap

R2(config-if)#ppp pap sent-username papuser password pappassword

setup ppp authentication chap 

R1(config)#username R2 password chappassword

R1(config-if)#ppp authentication chap

R1(config-if)#compress stac

R1(config-if)#ppp reliable-link

R2(config)#interface multilink 1

R1(config-if)#ppp multilink

R1(config-if)#ip address 10.1.1.1 255.255.255.252

on interface level 

ser0/0 and ser 0/1

R1(config-if)#no ip address

R1(config-if)#ppp multilink group 1

R2(config)#username R1 password chappassword

R2(config-if)#ppp authentication chap

R2(config-if)#compress stac

R2(config-if)#ppp reliable-link

R2(config)#interface multilink 1

ser0/0 and ser 0/1

R2(config-if)#no ip address

R2(config-if)#ppp multilink group 1

GLBP

Gateway Load Balance Protocol is cisco proprietary protocol which gives a very efficient solution such as HSRP in addition to load balancing capability within a single GLBP group.

GLBP Operation
Active Virtual Gateway (AVG): response to ARP requests from hosts and assigns virtual MAC address to members of the GLBP group

Active Virtual Forwarder (AVF): A member of a GLBP group that discovers an Active Virtual Gateway AVG based on Hello messages, and learns its virtual MAC address from that AVG

Configure GLBP
glbp                    Gateway Load Balancing Protocol interface commands

R1(config-if)#glbp 10 ip 10.1.1.1
R1(config-if)#glbp 10 priority 110

R2#show glbp 
FastEthernet0/1 - Group 10
  State is Active
    2 state changes, last state change 00:05:36
  Virtual IP address is 10.1.1.1
  Hello time 3 sec, hold time 10 sec
    Next hello sent in 2.748 secs
  Redirect time 600 sec, forwarder time-out 14400 sec
  Preemption enabled, min delay 0 sec
  Active is local
  Standby is unknown
  Priority 100 (default)
  Weighting 100 (default 100), thresholds: lower 1, upper 100
  Load balancing: round-robin
  There are 2 forwarders (2 active)
  Forwarder 1
    State is Active
      1 state change, last state change 00:05:36
    MAC address is 0007.b400.0a01 (learnt)
    Owner ID is c004.809c.0001
    Redirection enabled, 253.616 sec remaining (maximum 600 sec)
    Time to live: 14053.612 sec (maximum 14400 sec)
    Preemption enabled, min delay 30 sec
    Active is local, weighting 100
    Arp replies sent: 1
  Forwarder 2
    State is Active
      1 state change, last state change 00:11:23
    MAC address is 0007.b400.0a02 (default)
    Owner ID is c002.1640.0001
    Redirection enabled
    Preemption enabled, min delay 30 sec
    Active is local, weighting 100

    Arp replies sent: 1




 

EIGRP - IPv6

EIGRP routing for IPv6 the same as IPv4 routing except you have enable the IPv6 routing with the following commands
you will see this error message if IPv6 routing not enabled
R1(config)#ipv6 router eigrp 10 
% IPv6 routing not enabled

R1(config)#ipv6 unicast-routing Enable unicast routing
R1(config)#ipv6 cef

R1(config)#ipv6 router eigrp 10
R1(config-rtr)#router-id 1.1.1.1

No network statements given at router config, instead its given at participating interface

R1(config-if)#ipv6 eigrp 10

Very important no shutdown to IPv6 EIGRP protocol 
or you will have errot message 

R3#show ipv6 eigrp interfaces 
IPv6-EIGRP interfaces for process 10

% EIGRP 10 is in SHUTDOWN

R2(config)#ipv6 router eigrp 10
R2(config-rtr)#no shut
R2(config-rtr)#
*Dec  6 01:47:09.363: %DUAL-5-NBRCHANGE: IPv6-EIGRP(0) 10: Neighbor FE80::C809:1DFF:FEA8:8 (Serial2/0) is up: new adjacency
*Dec  6 01:47:09.367: %DUAL-5-NBRCHANGE: IPv6-EIGRP(0) 10: Neighbor FE80::C80B:15FF:FE80:6 (FastEthernet0/1) is up: new adjacency

R2#show ipv6 route
IPv6 Routing Table - 11 entries
Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP
       U - Per-user Static route, M - MIPv6
       I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary
       O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2
       D - EIGRP, EX - EIGRP external
D   2000:1::/64 [90/30720]
     via FE80::C809:1DFF:FEA8:8, Serial2/0
     via FE80::C80B:15FF:FE80:6, FastEthernet0/1
C   2000:2::/64 [0/0]
     via ::, Serial2/0
L   2000:2::2/128 [0/0]
     via ::, Serial2/0
C   2000:3::/64 [0/0]
     via ::, FastEthernet0/1
L   2000:3::2/128 [0/0]
     via ::, FastEthernet0/1
C   2000:4::/64 [0/0]
     via ::, FastEthernet0/0
L   2000:4::1/128 [0/0]
     via ::, FastEthernet0/0
D   2000:11::1111/128 [90/158720]
     via FE80::C809:1DFF:FEA8:8, Serial2/0
     via FE80::C80B:15FF:FE80:6, FastEthernet0/1
LC  2000:22::2222/128 [0/0]
     via ::, Loopback0
D   2000:33::3333/128 [90/156160]
     via FE80::C809:1DFF:FEA8:8, Serial2/0
     via FE80::C80B:15FF:FE80:6, FastEthernet0/1
L   FF00::/8 [0/0]

     via ::, Null0

Verification commands

1. show ipv6 protocol 
2. show ipv6 eigrp interface
3. show ipv6 eigrp neighbors 
4. show ipv6 route
5. show ipv6 eigrp topology 
6. show ipv6 cef

Modifying K values

R3(config-rtr)#metric weights 0 1 1 1 0 0

Configure Neighbors Authentication 

R2(config)#key chain Test

R2(config-keychain-key)#key-string pa$$word

R2(config-if)#ipv6 authentication key-chain eigrp 10 Test

R2#2(config-if)#ipv6 authentication mode eigrp 10 md5 

R2#show key chain 
Key-chain Test:
    key 10 -- text "pa$$word"
        accept lifetime (always valid) - (always valid) [valid now]
        send lifetime (always valid) - (always valid) [valid now]

VRRP

VRRP is similar to HSRP

Virtual Router Redundancy Protocol (VRRP)
A standards-based First Hop Redundancy Protocol (FHRP)

Configure VRRP
R1(config-if)#vrrp 10 ip 10.1.1.1

R1#show vrrp
FastEthernet0/1 - Group 10
  State is Master  
  Virtual IP address is 10.1.1.1
  Virtual MAC address is 0000.5e00.010a
  Advertisement interval is 1.000 sec
  Preemption enabled
  Priority is 110
  Master Router is 10.1.1.2 (local), priority is 100
  Master Advertisement interval is 1.000 sec
  Master Down interval is 3.609 sec


R2(config-if)#vrrp 10 ip 10.1.1.1

R2(config-if)#do show vrrp
FastEthernet0/1 - Group 10
  State is Backup  
  Virtual IP address is 10.1.1.1
  Virtual MAC address is 0000.5e00.010a
  Advertisement interval is 1.000 sec
  Preemption enabled
  Priority is 100
  Master Router is 10.1.1.2, priority is 110
  Master Advertisement interval is 1.000 sec
  Master Down interval is 3.609 sec (expires in 3.269 sec)

HSRP

HSRP
Hot Standby Router Protocol is cisco proprietary protocol known as First hop Redundancy Protocol
one router or multi-layer switch that actively forwards traffic out of a subnet which called an active-router. If the active router becomes unavailable the second router can detect the absence of an active router and it becomes the active router which called the standby router (Backup router).

HSRP Operation
Clients configured with default gateway that is neither active or standby configured with, which means there is a virtual gateway ip address that clients point to along with virtual MAC address
Virtual Router which often called phantom router that have the actual gateway ip address clients point to.

How HSRP functions
Hello messages used to elect an active router and to inform the standby router that the active router is still available.
Hello messages sent out every 3 seconds, there is also Holdertime Timer (a time after which the standby router becomes that active router (default of 10 senconds)
HSRP ver 2 Holdtimer can be configured in milliseconds, that is how standby router can determine an active router has gone down.

Active Router Election 
The router or multi-layer switch with the highest priority is elected as the active router (default priority is 100)

Tracking option
Allows an HSRP router to monitor a network condition such as interface status, and decrements its priority based on that condition.

Preeampt Option
HSRP's preempt option allows a router that was previously the active router to reclaim its rule active router, if it goes down and comes a backup.

Configuring HSRP

R1(config-if)#stan
R1(config-if)#standby 10 ip 10.1.1.1
R1(config-if)#
*Dec  4 19:35:18.983: %HSRP-5-STATECHANGE: FastEthernet0/1 Grp 10 state Standby -> Active

R2(config-if)#standby 10 ip 10.1.1.1
R2(config-if)#
*Dec  4 20:16:50.203: %HSRP-5-STATECHANGE: FastEthernet0/1 Grp 10 state Speak -> Standby




R2(config-if)#standby 1 ip 10.1.1.1
R2(config-if)#
*Mar  1 00:05:32.695: HSRP: Fa0/1 Grp 1 Disabled -> Init
*Mar  1 00:05:32.695: HSRP: Fa0/1 Grp 1 Redundancy "hsrp-Fa0/1-1" state Disabled -> Init

R2(config-if)#
*Mar  1 00:05:42.699: HSRP: Fa0/1 Grp 1 Active router is 10.1.1.2
*Mar  1 00:05:42.699: HSRP: Fa0/1 Interface up
*Mar  1 00:05:42.699: HSRP: Fa0/1 Starting minimum interface delay (1 secs)
*Mar  1 00:05:43.699: HSRP: Fa0/1 Interface min delay expired
*Mar  1 00:05:43.699: HSRP: Fa0/1 Grp 1 Init: a/HSRP enabled
*Mar  1 00:05:43.699: HSRP: Fa0/1 Grp 1 Init -> Listen
*Mar  1 00:05:43.699: HSRP: Fa0/1 Grp 1 Redundancy "hsrp-Fa0/1-1" state Init -> Backup
*Mar  1 00:05:53.699: HSRP: Fa0/1 Grp 1 Listen: d/Standby timer expired (unknown)
*Mar  1 00:05:53.699: HSRP: Fa0/1 Grp 1 Listen -> Speak
*Mar  1 00:05:53.699: HSRP: Fa0/1 Grp 1 Redundancy "hsrp-Fa0/1-1" state Backup -> Speak
*Mar  1 00:06:03.775: HSRP: Fa0/1 Grp 1 Speak: d/Standby timer expired (unknown)
*Mar  1 00:06:03.775: HSRP: Fa0/1 Grp 1 Standby router is local
*Mar  1 00:06:03.775: HSRP: Fa0/1 Grp 1 Speak -> Standby
*Mar  1 00:06:03.775: HSRP: Fa0/1 Grp 1 Redundancy "hsrp-Fa0/1-1" state Speak -> Standby
R2(config-if)#

Standby Content Help
R2(config-if)#standby ?
  <0-255>         group number
  authentication  Authentication
  delay           HSRP initialisation delay
  ip              Enable HSRP and set the virtual IP address
  mac-address     Virtual MAC address
  name            Redundancy name string
  preempt         Overthrow lower priority Active routers
  priority        Priority level
  redirects       Configure sending of ICMP Redirect messages with an HSRP
                  virtual IP address as the gateway IP address
  timers          Hello and hold timers
  track           Priority tracking
  use-bia         HSRP uses interface's burned in address

R2(config-if)#standby 1 ?
  authentication  Authentication
  ip              Enable HSRP and set the virtual IP address
  mac-address     Virtual MAC address
  name            Redundancy name string
  preempt         Overthrow lower priority Active routers
  priority        Priority level
  timers          Hello and hold timers
  track           Priority tracking

R1#show standby brief 
                     P indicates configured to preempt.
                     |
Interface   Grp Prio P State    Active          Standby         Virtual IP  
Fa0/1       1   100    Active   local           10.1.1.3        10.1.1.1    
R1#

R2#show standby brief 
                     P indicates configured to preempt.
                     |
Interface   Grp Prio P State    Active          Standby         Virtual IP  
Fa0/1       1   100    Standby  10.1.1.2        local           10.1.1.1    
R2#


R2(config-if)#
*Mar  1 00:39:03.035: HSRP: Fa0/1 Grp 1 Coup   in  10.1.1.2 Standby pri 110 vIP 10.1.1.1
*Mar  1 00:39:03.035: HSRP: Fa0/1 Grp 1 Active: j/Coup rcvd from higher pri router (110/10.1.1.2)
*Mar  1 00:39:03.035: HSRP: Fa0/1 Grp 1 Active router is 10.1.1.2, was local
*Mar  1 00:39:03.035: HSRP: Fa0/1 Grp 1 Standby router is unknown, was 10.1.1.2
*Mar  1 00:39:03.039: HSRP: Fa0/1 Grp 1 Active -> Speak
*Mar  1 00:39:03.039: %HSRP-6-STATECHANGE: FastEthernet0/1 Grp 1 state Active -> Speak
R2(config-if)#
*Mar  1 00:39:03.039: HSRP: Fa0/1 Grp 1 Redundancy "hsrp-Fa0/1-1" state Active -> Speak
R2(config-if)#
*Mar  1 00:39:13.035: HSRP: Fa0/1 Grp 1 Speak: d/Standby timer expired (unknown)
*Mar  1 00:39:13.035: HSRP: Fa0/1 Grp 1 Standby router is local
*Mar  1 00:39:13.035: HSRP: Fa0/1 Grp 1 Speak -> Standby
*Mar  1 00:39:13.035: HSRP: Fa0/1 Grp 1 Redundancy "hsrp-Fa0/1-1" state Speak -> Standby
R2(config-if)#
*Mar  1 00:39:26.131: HSRP: Fa0/1 Grp 1 Standby: h/Hello rcvd from lower pri Active router (80/10.1.1.2)
*Mar  1 00:39:26.131: HSRP: Fa0/1 Grp 1 Active router is local, was 10.1.1.2
*Mar  1 00:39:26.131: HSRP: Fa0/1 Grp 1 Standby router is unknown, was local
*Mar  1 00:39:26.135: HSRP: Fa0/1 Grp 1 Coup   out 10.1.1.3 Standby pri 100 vIP 10.1.1.1
*Mar  1 00:39:26.135: HSRP: Fa0/1 Grp 1 Standby -> Active
*Mar  1 00:39:26.135: %HSRP-6-STATECHANGE: FastEthernet0/1 Grp 1 state Standby -> Active
R2(config-if)#
*Mar  1 00:39:26.135: HSRP: Fa0/1 Grp 1 Redundancy "hsrp-Fa0/1-1" state Standby -> Active
*Mar  1 00:39:26.243: HSRP: Fa0/1 Grp 1 Resign in  10.1.1.2 Speak   pri 80 vIP 10.1.1.1
*Mar  1 00:39:26.243: HSRP: Fa0/1 Grp 1 Active: i/Resign rcvd (80/10.1.1.2)
*Mar  1 00:39:26.243: HSRP: Fa0/1 Grp 1 Coup   out 10.1.1.3 Active  pri 100 vIP 10.1.1.1
R2(config-if)#
*Mar  1 00:39:29.247: HSRP: Fa0/1 Grp 1 Redundancy group hsrp-Fa0/1-1 state Active -> Active
R2(config-if)#
*Mar  1 00:39:32.247: HSRP: Fa0/1 Grp 1 Redundancy group hsrp-Fa0/1-1 state Active -> Active
R2(config-if)#
*Mar  1 00:39:37.895: HSRP: Fa0/1 Grp 1 Standby router is 10.1.1.2


R1#show standby
FastEthernet0/1 - Group 1
  State is Active
    14 state changes, last state change 00:00:41
  Virtual IP address is 10.1.1.1
  Active virtual MAC address is 0000.0c07.ac01
                  Cisco Vender Code HSRP Ver 1.0 Group#<0-255>     group number
                                                    0000.0c9f.f001
                  Cisco Vender Code HSRP Ver 2.0 Group#  <0-4095> group number
    Local virtual MAC address is 0000.0c07.ac01 (default)
  Hello time 3 sec, hold time 10 sec
    Next hello sent in 0.468 secs
  Preemption enabled
  Active router is local
  Standby router is 10.1.1.3, priority 100 (expires in 9.804 sec)
  Priority 110 (configured 110)
    Track interface FastEthernet0/0 state Up decrement 30
  IP redundancy name is "hsrp-Fa0/1-1" (default)

R2#show ip arp
Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  10.1.1.3                -   c002.1640.0001  ARPA   FastEthernet0/1
Internet  10.1.1.1                -   0000.0c07.ac01  ARPA   FastEthernet0/1
Internet  192.168.14.2            0   0050.56e8.e3c1  ARPA   FastEthernet0/0
Internet  10.1.1.100             44   0050.7966.6800  ARPA   FastEthernet0/1
Internet  192.168.14.254         32   0050.56fd.eee2  ARPA   FastEthernet0/0
Internet  192.168.14.141          -   c002.1640.0000  ARPA   FastEthernet0/0

EIGRP

Characteristics of EIGRP
Enhanced Interior Gateway Routing Protocol, and advanced link state routing protocol

• Fast conversion
• scalable
• Load balancing over unequal cost links
• classless (VLSM)
• Communicates via multicast 224.0.0.10
• was cisco-proprietary

Routing Structure

• EIGRP maintains 3 tables (Neighbor, Interface & Topology)
• EIGRP keeps track of its adjacent neighbors command (show ip eigrp neighbors)
• Interface table which contains a list of interfaces participating in EIGRP Autonomous System command (show ip eigrp interfaces)
• EIGRP Topology table which contains routes to network destination, command (show ip eigrp topology)

Path Selection

• How EIGRP makes path selection decision 
• EIGRP  uses DUAL algorithm (diffusing Update Algorithm) a calculation made by EIGRP to determine the best loop-free path to a network
• Advertised Distance (AD) the Distance (metric value) of a neighboring router to reach a network. Advertised Distance is sometimes called the Reported Distance (RD)
• Feasible Distance (FD): a neighbor's Advertised Distance to a network plus the distance to reach that neighbor
• Successor Router: the primary route to have a network, based on the route having the lowest Feasible Distance (FD) of all routes in the EIGRP topology table.
• Feasible Successor Route: a backup route to a network, based on the route having the second lowest feasible distance in the EIGRP topology (the feasibility condition must be met)
• Feasibility condition: before a route can become a Feasible Successor Route, its Advertised Distance (AD) has to be lower than the Feasible Distance of the successor route. 

Metric Calculation

1. Bandwidth
2. Delay
3. Reliability
4. Load
5. MTU

Metric = [(K1*Bandwidth + (K2*Bandwidth)/(256-Load)+K3*Delay)*K5/(K4+Reliability)]*256

Default K values

K1=1

K2=0

K3=1

K4=0

K5=0

By adding K values into metric formula 

Metric=(Bandwidth + Delay)*256

Metric=[(10,000,000/)+(sum of interface Delays/10)]*256

EIGRP Configuration
from Global configuration mode
Router Eigrp followed by Autonomous system number
Enter networks followed by wildcard mask

R2#sho ip eigrp topology 
IP-EIGRP Topology Table for AS(100)/ID(2.2.2.2)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
       r - reply Status, s - sia Status

P 3.3.3.3/32, 1 successors, FD is 156160
        via 192.168.1.1 (156160/128256), FastEthernet0/1
P 1.1.1.1/32, 1 successors, FD is 158720
        via 192.168.1.1 (158720/156160), FastEthernet0/1
        via 172.16.1.1 (2297856/128256), Serial0/1
P 2.2.2.2/32, 1 successors, FD is 128256
        via Connected, Loopback0
P 10.1.1.0/24, 1 successors, FD is 30720
        via 192.168.1.1 (30720/28160), FastEthernet0/1
        via 172.16.1.1 (2172416/28160), Serial0/1
P 192.168.1.0/30, 1 successors, FD is 28160
        via Connected, FastEthernet0/1
P 172.16.1.0/30, 1 successors, FD is 2169856
        via Connected, Serial0/1

R2#show ip eigrp interfaces 
IP-EIGRP interfaces for process 100

                        Xmit Queue   Mean   Pacing Time   Multicast    Pending
Interface        Peers  Un/Reliable  SRTT   Un/Reliable   Flow Timer   Routes
Lo0                0        0/0         0       0/10           0           0
Se0/1              1        0/0       173       0/15         863           0

Fa0/1              1        0/0      1793       0/10        5936           0

R2#show ip eigrp neighbors
IP-EIGRP neighbors for process 100
H   Address                 Interface       Hold Uptime   SRTT   RTO  Q  Seq
                                            (sec)         (ms)       Cnt Num
1   192.168.1.1             Fa0/1             11 00:08:21 1793  5000  0  11
0   172.16.1.1              Se0/1             13 00:09:18  173  1038  0  20

R2#sho ip cef
Prefix              Next Hop             Interface
0.0.0.0/0           drop                 Null0 (default route handler entry)
0.0.0.0/32          receive
1.1.1.1/32          192.168.1.1          FastEthernet0/1
2.2.2.2/32          receive
3.3.3.3/32          192.168.1.1          FastEthernet0/1
10.1.1.0/24         192.168.1.1          FastEthernet0/1
10.2.2.0/24         attached             FastEthernet0/0
10.2.2.0/32         receive
10.2.2.1/32         receive
10.2.2.255/32       receive
172.16.1.0/30       attached             Serial0/1
172.16.1.0/32       receive
172.16.1.2/32       receive
172.16.1.3/32       receive
192.168.1.0/30      attached             FastEthernet0/1
192.168.1.0/32      receive
192.168.1.1/32      192.168.1.1          FastEthernet0/1
192.168.1.2/32      receive
192.168.1.3/32      receive
224.0.0.0/4         drop
224.0.0.0/24        receive
255.255.255.255/32  receive

Configure unequal Cost Load Balancing 
By default OSPF and EIGRP can load balance over an equal cost links

Example:

routing table shows only one path to 1.1.1.1

EIGRP topolofy shows it has 2 paths to 1.1.1.1

WHY?
its very simple why, because of the feasible distance is less 158720 < 2297856

by using this command we can inject another path in the routing table which is to be our load balance link
variance             Control load balancing variance

R2(config-router)#variance ?
  <1-128>  Metric variance multiplier

how to figure out the variance number?
Simple way in doing that!

by dividing the worst FD / Best FD
2297856 / 158720 = 14.4 is not enough which we have to round up to 15

R2(config-router)#variance 15

EIGRP Auto-summary
Auto-summary can reduce the individual route in routing table EIGRP can summarize networks at their classfull boundaries using their natural mask which can be a great thing to reduce size of the ip routing table it could a problem for discontiguous that can cause a problem

R1#show ip protocols
Routing Protocol is "eigrp 100"
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Default networks flagged in outgoing updates
  Default networks accepted from incoming updates
  EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
  EIGRP maximum hopcount 100
  EIGRP maximum metric variance 1
  Redistributing: eigrp 100
  EIGRP NSF-aware route hold timer is 240s
  Automatic network summarization is in effect
  Automatic address summarization:
    172.16.0.0/16 for Loopback0, FastEthernet0/0
      Summarizing with metric 2169856
    10.0.0.0/8 for Loopback0, Serial2/0
      Summarizing with metric 28160
    1.0.0.0/8 for FastEthernet0/0, Serial2/0
      Summarizing with metric 128256
  Maximum path: 4
  Routing for Networks:
    1.1.1.1/32
    10.1.1.0/24
    172.16.1.0/30
  Routing Information Sources:
    Gateway         Distance      Last Update
    (this router)         90      00:02:38
    10.1.1.2              90      00:02:38
    172.16.1.2            90      00:02:38
  Distance: internal 90 external 170


Configure Passive Interface

hello packet passes through this interface which is connected to a switch, which might be a security issue

!
router eigrp 100
 variance 15
 passive-interface FastEthernet0/0
 network 2.2.2.2 0.0.0.0
 network 10.2.2.0 0.0.0.255
 network 172.16.1.0 0.0.0.3
 network 192.168.1.0 0.0.0.3
 no auto-summary
!

Passive interface will not send hello packets

Troubleshooting

1. show ip route
2. show ip protocols
3. show ip eigrp neighbors
4. show ip eigrp topology
5. show ip cef
6. matching K values
7. look for authentication mismatch
8. EIGRP AS# mismatch
9. look for passive interface 

OSPFv3

OSPFv2 does not support IPv6
IPv6 is supported by OSPFv3 which can be configured from the interface
with following commands

couple of commands that need to enabled for IPv6 routing to work
ipv6 cef                      Cisco Express Forwarding for IPv6
Cisco Express Forwarding (allow routers to making and an efficient routing decisions based on FIB (forwarding Information Base) and adjacency table 
ipv6 unicast-routing   Enable unicast routing (which enables the router to route traffic based on destination IPv6 addresses)

R1>interfaces ip information
interface Loopback0
ip address 1.1.1.1 255.255.255.255
interface FastEthernet0/0
no ip address
duplex auto

speed auto

ipv6 address 2000:11AA::1/64

interface FastEthernet1/0

no ip address

duplex auto

speed auto

ipv6 address 2000:1122::1/64

Configuring OSPv3  do the same commands on R2 & R3

R1# conf ter

Enter configuration commands, one per line.  End with CNTL/Z.

R1(config)#ipv

R1(config)#ipv6 router

R1(config)#ipv6 router os

R1(config)#ipv6 router ospf 1

R1(config-rtr)#router-id 

Note: error message if IPv6 unicast not enable 

R2(config)#ipv6 router ospf 1

% IPv6 routing not enabled

configuring interfaces with OSPFv3 with with this command 

R1#conf ter

Enter configuration commands, one per line.  End with CNTL/Z.

R1(config)#inter fas

R1(config)#inter fastEthernet 0/0

R1(config-if)#ipv

R1(config-if)#ipv6 osp

R1(config-if)#ipv6 ospf ?

  <1-65535>            Process ID

  authentication       Enable authentication

  cost                 Interface cost

  database-filter      Filter OSPF LSA during synchronization and flooding

  dead-interval        Interval after which a neighbor is declared dead

  demand-circuit       OSPF demand circuit

  flood-reduction      OSPF Flood Reduction

  hello-interval       Time between HELLO packets

  mtu-ignore           Ignores the MTU in DBD packets

  neighbor             OSPF neighbor

  network              Network type

  priority             Router priority

  retransmit-interval  Time between retransmitting lost link state

                       advertisements

  transmit-delay       Link state transmit delay

R1(config-if)#ipv6 ospf 1 are

R1(config-if)#ipv6 ospf 1 area 0

R1(config-if)#

R2(config)#interface fas 0/0

R2(config-if)#ipv

R2(config-if)#ipv6 osp

R2(config-if)#ipv6 ospf 1 area 0

R2(config-if)#

*Mar  1 01:06:29.099: %OSPFv3-5-ADJCHG: Process 1, Nbr 1.1.1.1 on FastEthernet0/0 from LOADING to FULL, Loading Done

As soon we configured R2 interface adjacency formed with neibhor R1 with router-id 1.1.1.1

R3

R3#conf ter

Enter configuration commands, one per line.  End with CNTL/Z.

R3(config)#inter ser 1/0

R3(config-if)#ipv

R3(config-if)#ipv6 osp

R3(config-if)#ipv6 ospf 1 area

R3(config-if)#ipv6 ospf 1 area  1

R3(config-if)#

*Mar  1 01:10:03.855: %OSPFv3-5-ADJCHG: Process 1, Nbr 2.2.2.2 on Serial1/0 from LOADING to FULL, Loading Done

R3(config-if)#

For R3 adjacency formed neighbor relationship with router R2 router-ir 2.2.2.2 through serial interface 

Verification Commands

R3#ping 2000:11aa::1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2000:11AA::1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 16/23/36 ms

R3#sho ipv

R3#sho ipv6 route

R3#sho ipv6 route

IPv6 Routing Table - 8 entries

Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP

       U - Per-user Static route

       I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary

       O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2

       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2

OI  2000:1122::/64 [110/65]

     via FE80::CE02:24FF:FE7C:0, Serial1/0

OI  2000:11AA::/64 [110/66]

     via FE80::CE02:24FF:FE7C:0, Serial1/0

C   2000:2233::/64 [0/0]

     via ::, Serial1/0

L   2000:2233::3/128 [0/0]

     via ::, Serial1/0

C   2000:33AA::/64 [0/0]

     via ::, FastEthernet0/0

L   2000:33AA::3/128 [0/0]

     via ::, FastEthernet0/0

L   FE80::/10 [0/0]

     via ::, Null0

L   FF00::/8 [0/0]

     via ::, Null0

R3#

R3#show ipv6 interface brief 

FastEthernet0/0            [up/up]

    FE80::CE03:16FF:FE24:0

    2000:33AA::3

Serial1/0                  [up/up]

    FE80::CE03:16FF:FE24:0

    2000:2233::3

Serial1/1                  [administratively down/down]

    unassigned

Serial1/2                  [administratively down/down]

    unassigned

Serial1/3                  [administratively down/down]

    unassigned

FastEthernet2/0            [administratively down/down]

    unassigned

FastEthernet3/0            [administratively down/down]

    unassigned

Loopback0                  [up/up]

    unassigned

R3#

R3#traceroute 2000:11aa::1

Type escape sequence to abort.

Tracing the route to 2000:11AA::1

  1 2000:2233::2 4 msec 24 msec 20 msec

  2 2000:11AA::1 20 msec 24 msec 16 msec

R3#

R3#show ipv6 ospf neighbor                                          

Neighbor ID     Pri   State           Dead Time   Interface ID    Interface

2.2.2.2           1   FULL/  -        00:00:35    5               Serial1/0

R3#

R3#show ipv6 ospf interface serial 1/0

Serial1/0 is up, line protocol is up 

  Link Local Address FE80::CE03:16FF:FE24:0, Interface ID 5

  Area 1, Process ID 1, Instance ID 0, Router ID 3.3.3.3

  Network Type POINT_TO_POINT, Cost: 64

  Transmit Delay is 1 sec, State POINT_TO_POINT, Cost: 64

  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

    Hello due in 00:00:03

  Index 1/1/1, flood queue length 0

  Next 0x0(0)/0x0(0)/0x0(0)

  Last flood scan length is 1, maximum is 1

  Last flood scan time is 0 msec, maximum is 0 msec

  Neighbor Count is 1, Adjacent neighbor count is 1 

    Adjacent with neighbor 2.2.2.2

  Suppress hello for 0 neighbor(s)

R3#

R3#sho ipv6 protocols 

IPv6 Routing Protocol is "connected"

IPv6 Routing Protocol is "static"

IPv6 Routing Protocol is "ospf 1"

  Interfaces (Area 1):

    Serial1/0

  Redistribution:

    None

R3#

R3#show ipv6 cef 

2000:1122::/64

     nexthop FE80::CE02:24FF:FE7C:0 Serial1/0 

2000:11AA::/64

     nexthop FE80::CE02:24FF:FE7C:0 Serial1/0 

2000:2233::3/128

  Receive

2000:2233::/64

     attached to Serial1/0 

2000:33AA::3/128

  Receive

2000:33AA::/64

     attached to FastEthernet0/0 

FE80::/10

  Receive

FF00::/8

  Receive

R3#

OSPF Step-by-Step

understand basic OSPF routing protocol and how its functions and what type of algorithm it uses to select best routs

OSPF Basics

• Open standard devloped by IETF
• Establishes Adjacency with routers 
• Sends Link State Advertisments LSA's to other routers in an area
• Constructs a links state database from received LSA's 
• Runs Dijkstra Shortest Path First for algorithm to determine the shortest path to a network
• Attempts to inject the best path for each network into a router's routing table

OSPF Terminology 

• Hello: a protocol used to discover OSPF neighbors and confirm reachability to chose neighbors also used in elections of designated routers.
• Link State Advertisement (LSA): information a router sends and receives about network reachability, used to construct a router 's link state database.
• Links State Update LSU: a packet that carries LSA's 
• Link State Request LSR: used by a router to request specific LSA information from a neighbor
• Link State Acknowledgement LSACK: used bu router to confirm it received LSU

DR and BDR

Adjacencies only to be formed with DR and BDR

How DR gets Elected ?

• Hello protocol used to elect a DR
• During DR election, router with highest priority value wins.
• OSPF priority value is associated with an interface and can be a value in range 0 - 255
• An OSPF priority value 0 means that the router will not become a DR
• The default Priority value of an interface is 1
• If the priorities tie, the router with highest router ID (RID) becomes DR
• A router ID can be configured in router configuration mode, with command router-id value
• If an RID is not configured, the highest IP address of a loopback interface becomes the RID
• If a router no loopback interface, the highest IP address of non-loopback interface becomes the RID

Types of LSA

OSPF Example with 2 Areas