Had a question regarding OSPF fast hello. Lets say i configure fast hello on an interface using the command:
ip ospf dead-interval minimal hello-multiplier 5
This means my dead interval is 1 second (this value never changes)
This also means 5 hellos are sent out within 1 second which equals a hello message every 200ms
I have two question
1. Firstly dead interval doesnt follow the normal behaviour of 3 times the hello interval, with fast hellos dead interval is set to 1 second irrespective of hello interval - is this correct?
2. If dead interval is set to 1 second the what is the point of specifying the hello multiplier ie, does it really matter what the multiplier is set to? Even if it set to 100ms per hello or 200ms per hello dead interval will not happen until 1 sec.
2. Yeah... but it makes it possible for the router to "miss" some hellos without tearing the connection down. Because it is alot of hellos so the chanse is greater that it will miss some hellos over a congested link.
by default, Cisco recommends to have the Dead times 4 times the Hello timers.
In this case, if the dead timer is 1 sec, then the hello packets are sent every 250 ms.
The reason why we set the dead timers to be 4 times the hello timers is , even if we miss out one hello packet, the adjacency/neighborship should not go down. so we will wait for 4 hello's to elapse before we declare the neighborship as down.
Hello timer is then technically 0 seconds when you user fast hellos. So even if you confiure 4 hellos/sec on one router the other router can have 5 hellos/sec and adjecency will still form (equal hello/dead timer is a mandatory requirement for adjecency to form in OSPF (except for this)).
Question We run asr9001 with XR 6.1.3, and we have a very long delay to
login w/ SSH 1 or 2 to the device compare to IOS device. After
investigation, the there is 1s delay between the client KEXDH_INIT and
the server (XR) KEXDH_REPLY. After debug ssh serv...
Introduction The purpose of this document is to demonstrate the Open
Shortest Path First (OSPF) behavior when the V-bit (Virtual-link bit) is
present in a non-backbone area. The V-bit is signaled in Type-1 LSA only
if the router is the endpoint of one or ...
Hi, I am seeing quite a few issues with patch install and wanted to
share my experience and workaround to this. Login to admin via CLI, then
access root with the “shell” command Issue “df –h” and you’ll probably
see the following directory full or nearly ...