In the section we're going to talk about h s r b protocol
first top redundancy Perko F. H R P is a computer networking protocol which is designed to protect the
default gateway used on some network by allowing two or more hours to provide backup for the address
in the event of a failure of an active rather the backup brother will take over the address usually
within a few seconds.
In practice such protocols can also be used to protect other services operating on a single IP address.
Not just rodders
hot Stemberg rather protocol HRP is a running protocol that allows a host computers on the internet
to use multiple rather that act as a single virtual rather maintaining the connectivity even if the
first hop rather fails because other mothers are on standby and they're ready to go.
Rachel I.P and Emeka races are shared between the two brothers and there is no load balancing and were
fired by the Sjostrom by command.
As you can see that in our figure we have two others and they are rather one and rather two.
And please pay attention that I'm using edgers are paid to protect to default gateway for here and here.
If there is a problem in that rudders this interface or if that rather fails completely for example
we can have an power unit problem or we can have a cable problem in the interface connecting between
switch and the router if this rather is the active one the HSR protocol will switch the traffic to the
Sambre of.
This is actually what HRP is doing.
But there is no load balancing.
As I said for example if this one is active for other rather one is the act of further traffic flows
in that direction and there is no packet in here.
When this guy fails the traffic is switched to this direction.
And if I call for your preemption on rather wan.
For example let's say that I have fixed the power unit problem and if I configured preemption as well
this rather will become the active gateway again.
And this guy will act as a standby.
So let's take a look how we select the active and the standby gateways in the aitches happy as you can
see that in the figure we have two brothers again and the router with their highest IP address will
be active by default but the selection can be changed with the HSR property value rather with the highest
etches happy price to Wolley becomes active and default property value is 100 the active and the stem
brothers send the helo packets to the aitches or peer group mouth.
Guess others in 3 seconds.
If the help Pecka does not arrive in 10 seconds the standby rather becomes active.
OK let's say that this guy is active again and this guy has standby.
If I want to change the roles if I want to make this guy as an active I need to increase the price to
all the office rather when I think his approach to all of you this guy will be active and traffic will
follow.
In this direction is that of this direction in HS or the active gateway propagates this Mechel us and
SES that hey guys use this mac address widget x x is the atheist or peer group identifier to reach the
IP address which is HAARP.
By IP.
Let's talk about the topology.
Now we have a PC in here which has an IP address of 10.
That 100 the gateway address of the PC is 10 to 1.
And please pay attention that that's the HSR IP IP so I'm at I'm going to attach these I address to
this interface of the rather one and I'm going to attach this IP address to this interface of rather.
True and I'm going to attach S10 by IP for both of them and that's going to be turned up one and I'm
going to define the gateway as Tanda one.
So what the thing about this for example why I'm not attaching the tender to as Gateway let's say that
the good ways tend to if good they will be turned up to ival follow this line to send the packets to
weather and that work great.
But when these rather fails if this if there is a problem with this rather in at work
because of the 10 that too will fail also Also I wouldn't go to why they're in that work.
But if I can figure this one whenever this rather Frails rather too will be active for other and take
effect on trade and I'm going to reduce the weather in at work again without any interruption.
Let's take a look to the preemption feature.
If the active role of fails the standby rather is activated and it remains active even if the previous
active rather is return preemption process forces rather to a new HSR P selection.
And here are the states of the HSR brothers.
We have six six states and the first phase is initial.
This is the beginning state that indicates HAARP is not running.
It happens when the configuration changes or the interface is first turned on in the last day rather
has not at all my the virtual IP address and has not yet seen an authenticated helo message from the
active rudder in this state.
Rather we'll still wait to hear from the active rather in the listening state rather knows.
But IPN makers of the ritual rather.
But it's not the active or standby in this big state.
Rather sends periodic etches Arpey hello's and participates in the action of active or standby rather
in a standby state rather mudders how low packets from the active for other and it will take the active
state and the current active Crowder fails and in the active state through other forward packets that
are sent to the HRP group the rudder also sends periodic helo message's.
And here is the configuration of the HSR.
First I need to fix the IP addresses for my configuration.
The IP address in here is
thirty two.
And here is thought that Tori and my get Gateway s
third it up 1 and my H R P is also
they they're doing the configuration is ongoing under the interface mode and I'm assigning the IP addresses
at thirded up to and third that three to the physico interfaces.
These are four here and four here.
Then I'm going to attach the standby IP by using standby and some by group number and IP and the IP
address OK I'm doing the same thing on rather to to I just heard two different configurations for rather
one in here sent by one Pertti 150.
This line shows me that rather one is the active for for this HAARP topology.
Because of the default volley of the press it is 100 if I choose the 150.
This guy will be active from here as you can see that I taps them by wump preempt command which means
I configured the preemption.
For example if this rather fails
this guy will be active from but when this rudder is back this guy will be ystem by again.
And rather one will be active because configure the preemption 12:5 Daiches IP configuration.
I'm using the show standby command and I can see the group number State active virtual Mac address and
standby by others IP as well.
By typing this shows on by comment I can use different good ways for different real.
In HS are paid to.
And this is what multa group HAARP is doing for me.
For example for Villon tem and reelin 20 I'm using this guy as primary and I'm using this guy as the
second word for willen 20 million 10.
Then I'm getting under the interface we learn.
For example interface will antenne I'm attaching air lower priority for real antenna and high priority
for me than 20 which means this is going to be active for Villa 20.
And this is going to be in standby mode for the we learn Ted
etches R.P. has another great feature that is known as Sarpy interface trecking.
As I told you in the first flight Sarpy always is responsible for protecting the default gateway interfaces
but when I try to connect the internet I have also these interfaces as well.
So what or is doing without interference trecking HAARP is watching that if this interface is up or
not.
If this interface fails for example if serial 0 0 interface fails what HSR is doing this is DiClemente
profitable for one and rather b is becoming the active for others.
So I'm not having an interruption.
So traffic is flowing in this direction.
So another thing that HAARP can do is object tracking.
For example let's say that I have not problem in this in this interface to and everything is OK in my
local area network.
Here is my local area work my rudder is working fine and there is no problem in this interface or this
interface.
Everything is OK but there may be a problem on the
ISP network.
Maybe I hower central router in here that I'm collecting the traffic from the branch offices but HAARP
object tracking does.
I can think here these interfaces of my HQ router and if pink fails to the HQ rather
I can't change the traffic pattern again and maybe I can use another ISP and and Central rather and
so that my traffic won't interrupt
object traffic conflagration as well.
Under-funding and I personally and I'm trying to pin this IP address as you can see that I have a local
area in which I have rather one and rather two.
And on the other side I have a corridor which is an IP address or from what
them under-funding for frequency which means that I'm going to ping here each five seconds then I'm
defining the start and the finish time of the HSR.
I'm sorry I personally then I'm trecking does IPA Salei.
And whenever there's a problem I'm going to decrement the probes really.
And the other rudder will switch as the active
etches are people.
Is the following two types of authentication and their plaintext.
And they end the five if you want to configure and the first you can use the semigroup authentication
and the five keys ring and the keystream number in this thread the group number is arbitrary you can
choose anything that you want if you want to configure a plaintext you can use them by for example one
authentication and you can use the string that you want all rather in a HRP group send hello pickup's
by default the helo timer is set to three seconds and the timer is set to 10 seconds.
It means that a hello packet is sent but when the errors are pissed then by group devices every three
seconds and the standby the West becomes active and help back up has not been listed for 10 seconds.
If you want to modify the helo and Houlton timer you can use standby semigroup number timers and Helo
time or time command.
There are two versions of the HRP and they are version 1 and the version 2 version 1 is the default
version of the protocol aitches IP version 2 ellos group numbers up up to 4000 and 96 thus allowing
you to use Villere number as the group number.
All devices in an ancient happy group must have the same version configured.
Otherwise are elements masses are not on to.