Re: Linkup, int up, etc...

2000-06-28 17:03:30
Subject: Re: Linkup, int up, etc...
From: Ray Schafer <schafer AT tkg DOT com>
To: nv-l AT lists.tivoli DOT com
Date: Wed, 28 Jun 2000 21:03:30 +0000
Gord Michaels wrote:

> [...]
> With regards to the routers, what is the difference between linkup and
> interface up ?

The link state of the interface has to do with the interface being physically
connected to a network.  If the cable is pulled (for example) or the hub or
switch it is connected to is disconnected, the link state will go down.  This
link state must be up for the interface to function.

> What is the difference between linkdown and interface down.

A link down is caused by loss of the link state (see above).  But an interface
down event in NetView will be caused only by a failure to ping the interface
from NetView.

> On the switches, what exactly is the meaning of linkdown? Does it just mean
> that
> a port is enabled but nothing is plugged into it??

That will do it.  Same explanation as for a router.

> Also, do I have this correct: The interface up/down traps are soliticed by
> NetView
> via polling, but the linkup/down traps are unsolicted. Do I have this
> correct?

Yes.  That is correct.

> Or, on the router, will you receive a linkdown for an interface which is
> still up
> but, has for instance, been unplugged from it's hub/switch ??

The router will know when the link state is down and will bring the interface
down.  There are two SNMP variables to look at (which NetView v6 uses in
SNMP-based polling):
interfaces.ifTable.ifEntry.ifAdminStatus.<if index>  and
interfaces.ifTable.ifEntry.ifOperStatus.<ifindex>.    Admin status is down
when an administrator downs the interface.  If it is Admin UP, by
operationally down, it is a down interface.  In the example you gave above,
the state should be Oper down, admin up.

Hope that helps!

> Any clarification here is much appreciated.
> Sincerely,
> Gord Michaels.
> ________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
> _________________________________________________________________________
> NV-L List information and Archives: http://www.tkg.com/nv-l

Ray Schafer                   | schafer AT tkg DOT com
The Kernel Group              | Distributed Systems Management

<Prev in Thread] Current Thread [Next in Thread>