What is Difference between Hello' and keepalive ?

[ganpatspatil]

i want to know what is difference between Hello' and keepalive ?

[gpulos]

a hello packet is crafted for a specific protocol that uses 'hello's'

ie: HSRP uses hello packets. EIGRP uses hello packets as well. these two protocols use their own version of a hello packet.

a hello packet announces some service or device to the network so that other services/devices of the same type can make connections with each other.

a keepAlive packet is used by devices that usually have already established a connection, and now use 'keepAlives' to inform the other side of the connection that the device/session is still active/connected.

most protocols that are connection oriented can use keepAlives. interfaces can be configured to use keepAlives as well in most cases.

[Richard Burts]

I think that Greg has given a good explanation of keepalive and hello. I would offer an explanation from a slightly different perspective.

While keepalive and hello share some common functionality there are some things that differentiate them. A keepalive is a function to validate the proper functioning and availability of an interface. As long as the device can send and receive keepalive messages it knows that the interface is functioning and is available to transmit data. While a hello also frequently has this function a hello also usually has some other functionality including the discovery of neighbors and initiating or maintaining a neighbor relationship.

HTH

Rick

[devang_etcom]

hi ganpat,

you can say both works for same...

but each and every protocol use HELLO for the various purpose...and with their own structure-means with their appropriate field... some time HELLO also carry information about what is it all about... which autonomus system or area it belongs to... what are the values of different timers...HELLO protocols timer should match to each other where as in keep alive you can have the different timers value...

but both are work for availability and status indication...

rate this post if it helps

regards

Devang