CCNA || cisco router high availability commend || TYPE :GLBP ,HSRP, VRRP

 GLBP ,HSRP, VRRP

1) GLBP=gateway load balancing protocol

Gateway Load Balancing Protocol (GLBP) protects data traffic from a failed router or circuit, like Hot Standby Router Protocol (HSRP) and Virtual Router Redundancy Protocol (VRRP), while allowing packet load sharing between a group of redundant routers.

-These protocol provide high availability with load balancing.

-cisco priopritary protocol.

-All gateway will be used by default in these techinque where as in HSRP/VRRP only 1 gateway will in use.

-It uses two technique

a) AVG=Active virtual gateway

b) AVF=Active Virtual Forwarder

- All multiple router must be in the same GLBP Group.

-Port : UDP 3222

-Hello:224.0.0.102

-AVG is use for handling for Gateway's and ARP request that ARP request came from Client - lan systems.

-Highest priority or highest ip address will be elected for AVG.

-Next priority or highest ip add will be elected for AVF.

-mac address:0007.b400.xxyy

whereas xx=group id , yy=AVF id.

-hello timer: 3sec Hold down timer:10 sec

-After 3 consecutive hello/10sec if neighbor router doesn't get hello then it declare dead.

-Load balance types

a) round robin (Default in use)

b) weighted

c) host-dependent 

- Higher priority/IP address will be AVG & other will be AVF mode.

- If AVF 1 is down then virtual mac add of AVF1 will be transfered to next AVF. meansR1 to R2.

so, that mac add will provide arp request.

-If R1 goes down till 10 min R2 will maintain R1 mac address entry after 10 min R2 will flush R1 mac address.

R1#int fa1/0

  glbp 1 priority 150

  glbp 1 ip 170.10.12.100

  glbp 1 timers redirect 120 1000

  glbp 1 timers msec 200 msec 600

  glbp 1 load-balancing weighted

  exit

  do sh history

  exit

  int fa1/0

  glbp 1 weighting 150 lower 90

  exit

  track 1 interface s0/0 line-protocol

  exi

  int fa1/0

  glbp 1 weighting track 1 decrement 70

  exit

  int s0/0

  shut

R2#int fa1/0

  glbp 1 priority 120

  glbp 1 ip 170.10.12.100

  glbp 1 timers redirect 120 1000

  glbp 1 timers msec 200 msec 600

  glbp 1 load-balancing weighted

  exi

  exit

int fa1/0

  glbp 1 weighting 150 lower 90

  exit

  track 1 interface s0/0 line-protocol

  exi

  int fa1/0

  glbp 1 weighting track 1 decrement 70

  exit

R3#int fa1/0

  glbp 1 priority 100

  glbp 1 ip 170.10.12.100

  glbp 1 timers redirect 120 1000

  glbp 1 timers msec 200 msec 600

  glbp 1 load-balancing weighted

  exi

  exit

int fa1/0

  glbp 1 weighting 150 lower 90

  exit

  track 1 interface s0/0 line-protocol

  exi

  int fa1/0

  glbp 1 weighting track 1 decrement 70 

exit

verification:

sh glbp brief

sh glbp 

User Traceroute from R1, R2,R3 & show them packet is use different path to reach destination.

here check prioprity,status, active router state.

smile... :) by: injoy143.blogspot.com ….Pradhyuman ghodela

 

Layer-3 Redundancy protocol

 

HSRP= Hot Standby Routing Protocol = Cisco prioprity protocol-->use for gw high availability.

VRRP= Virtual Router Redundancy  Protocol = open standard protocol-->use for gw high availability. 

GLBP= Gateway Load Balancing Protocol = Cisco Prioprity protocol.-->Load sharing & High availability provided

Each of the router provides redundancy for given gateway address.

one router with the higest priority or higher ip address as a primary or active HSRP router.

Then next highest ip add or higest priority will be the next standyby HSRP state router.

so, if the priority is same then higest ip add will use to elect as a active HSRP router. 

You can configure router immediately take over the role for highest at any time with

Preempt mode.

 mHSRP=Load sharing & High availability provided

multi HSRP

=================================================================

HSRP 

Hot Standby Router Protocol (HSRP) is a CISCO proprietary protocol, which provides redundancy for a local subnet. In HSRP, two or more routers gives an illusion of a virtual router. HSRP allows you to configure two or more routers as standby routers and only a single router as active router at a time.

  R1(config)#do sh history

  standby 1 ip 170.10.12.100

  standby 1 priority 120

  standby 1 timers msec 300 msec 900

  do sh history

  standby 1 preempt

  standby 1 track s0/0 30

  exit

  do sh history

  exit

  int s0/0

  shut

  int s0/0

  no shut

  key chain abc

  key 1

  key-string cisco123

  int fa1/0

  standby 1 authentication md5 key-chain abc

  do sh history

R2(config)#do sh history

    standby 1 ip 170.10.12.100

    standby 1 priority 110

    standby 1 timers msec 3000 msec 9000

    standby 1 timers msec 300 msec 900

    do sh history

    standby 1 preempt

    standby 1 track s0/0 30

    exit

    do sh history

  do sh history

  exit

  key chain abc

    key 1

    key-string cisco123

    int fa1/0

    standby 1 authentication md5 key-chain abc

  do sh history

  wr

  exit

  do sh history

R3(config)#do sh history

  en

    int fa1/0

    standby 1 ip 170.10.12.100

    standby 1 timers msec 3000 msec 9000

    standby 1 timers msec 300 msec 900

    do sh history

    standby 1 preempt

    standby 1 track s0/0 30

    exit

    do sh history

  do sh history

  exit

  key chain abc

    key 1

    key-string cisco123

    int fa1/0

    standby 1 authentication md5 key-chain abc

  do sh history

  exit

  do sh history

VRRP (Virtual Router Redundancy Protocol)

The Virtual Router Redundancy Protocol (VRRP) is a computer networking protocol that provides for automatic assignment of available Internet Protocol (IP) routers to participating hosts. This increases the availability and reliability of routing paths via automatic default gateway selections on an IP subnetwork.

 

·         It is alternative to HSRP, defined in IETF standard. (It is open standard protocol)

·         UDP,8888

·         The active router is called the master router, whereas all others are in the backup state.

·         One router is elected as the Master. This router has the highest priority value, or the highest IP address in the group, if there is no highest priority.

·         VRRP group : 0 to 255

·         Priority : 1 to 254 (default is 100)

·         virtual MAC address (0000.5E00.01xx, where xx is the hex VRRP group number)

·         VRRP advertisements are sent at 1-second intervals.

·         VRRP sends its advertisements to the multicast destination address 224.0.0.18

(VRRP), using IP protocol 112.

·         VRRP defaults to use pre-emption, but HSRP defaults to not use pre-emption.

·         In VRRP, you can set virtual IP address from any of the gateway (actual) IP address .

 On R1,

Conf t

Int f1/0

Vrrp 1 priority 150

Vrrp 1 ip 170.10.12.100

Vrrp 1 timers advertise msec 100

Vrrp 1 preempt delay minimum 10

Vrrp 1 track 1 decrement 40

Exit

Track 1 interface s0/0 line-protocol

exit

 

On R2,

Conf t

Int f1/0

Vrrp 1 priority 120

Vrrp 1 ip 170.10.12.100

Vrrp 1 timers advertise msec 100

Vrrp 1 preempt delay minimum 10

Vrrp 1 track 1 decrement 40

Exit

Track 1 interface s0/0 line-protocol

exit

 

On R3,

Conf t

Int f1/0

Vrrp 1 priority 100

Vrrp 1 ip 170.10.12.100

Vrrp 1 timers advertise msec 100

Vrrp 1 preempt delay minimum 10

Vrrp 1 track 1 decrement 40

Exit

Track 1 interface s0/0 line-protocol

exit

   Verification:

R1#sh vrrp  brief

Interface          Grp      Pri        Time   Own    Pre    State        Master addr      Group addr   Fa1/0                1       150         714                  Y    Master       170.10.12.1     170.10.12.100

 

R1#sh vrrp                                

R2#sh vrrp brief

Interface          Grp      Pri        Time   Own    Pre   State        Master addr          Group addr   Fa1/0                 1      120         831                  Y    Backup      170.10.12.1       170.10.12.100

From R5 & R6,

Trace 170.10.8.8

Now shutdown s0/0 port on R1,

Sh vrrp brief

From R5 & R6,

Trace 170.10.8.8

The following chart provides difference HSRP Vs VRRP Vs GLBP protocols.

Difference between HSRP, VRRP and GLBP Protocols

Protocol Features	HSRP	VRRP	GLBP
Scope	Cisco Proprietary	IEEE standard	Cisco proprietary
Standard	RFC2281	RFC3768	none
OSI Layer	Layer-3	Layer-3	Layer-2
Load Balancing	No	No	Yes
Multicast Group IP address	224.0.0.2 in version 1224.0.0.102 in version 2	224.0.0.18	224.0.0.102
Transport Port Number	UDP 1985	UDP 112	UDP 3222
Timers	Hello – 3 sec	Advertisement – 1 sec	Hello – 3sec
	Hold – 10 sec	Master down time = 3*Advertisement Time + Skew TimeSkew Time = (256-            Priority)/256	Hold – 10sec
Election	Active Router:1.Highest Priority2. Highest IP address (Tiebreaker)	Master Router: (*) 1-Highest Priority 2-Highest IP (Tiebreaker)	Active Virtual Gateway: 1-Highest Priority 2-Highest IP (Tiebreaker)
Router Role	-One Active Router, one Standby Router-one or morelistening Routers	– One Active Router- One or More Backup Routers	– One AVG (Active Virtual Gateway)- up to 4 AVF Routers on the group (Active Virtual Forwarder) passing traffic.- up to 1024 virtual Routers (GLBP groups) per physical interface.
Preempt	If Active Router(Highest Priority) is down and up again, Preempt should be configured to become a Active Router again	By default Preempt is ON in VRRP, If Active Router is down and up again, It will automatically become a MasterRouter	If Active Router(Highest Priority) is down and up again, Preempt should be configured to become a Active Router again.
Group Virtual Mac Address	0000.0c07.acxx	0000.5e00.01xx	0007.b4xx.xxxx
IPv6 support	Yes	No	Yes