Sue,
In addition to what ER had to say, the main purpose of
loopback address is actually contained in your
question.....loopback interface is always up/up, and
this helps you to possibly get into the router when
there is problem and all interfaces fail, now you can
see what is going on and troubleshoot after you have
telneted into the router....
inno/ccnp
--- Ednilson Rosa wrote:
> Sorry,
>
> Just a correction: the mask usually used for a
> loopback intf is /32
> (255.255.255.255) and not /24 (255.255.255.0).
>
> Rgards,
>
> ER
> CCNA
>
> ----- Original Message -----
> From: "Ednilson Rosa"
> To:
> Sent: Friday, June 22, 2001 1:20 PM
> Subject: Re: what is loopback interface for ?
> [7:9493]
>
>
> A loopback interface may be used for many purposes.
> You may use it as the
> end of a tunnel on a VPN configuration or you may
> configure it just to have
> a stable router-id for OSPF, for instance.
>
> You don't need to configure it. They are optional
> and you may use any
> address you want. If loopback intfs are following a
> specific address scheme
> in your network, then they must be planned for some
> specific function by who
> designed the network. You should not change it
> before knowing what function
> is this (what may be achieved by analyzing your
> configuration carefully).
>
> The subnet mask used on a loopback intf isn't also
> necessarily /24. This is
> frequently used though, to economize address space,
> since you don't need to
> differentiate network and host on this segment. In
> this case, host and
> network are the same and routing is performed with
> no problem.
>
> ER
> CCNA
>
> ----- Original Message -----
> From: "Susan Stone"
> To:
> Sent: Friday, June 22, 2001 7:22 AM
> Subject: what is loopback interface for ? [7:9493]
>
>
> Hi,
>
> I always wonder what is loopback interface for? Can
> anyone explained its
> function? Can we don't configure the loopback
> interface. Our WAN Lookback
> always start with 192.168.X.X why? Must we use
> private IP? I found I can
> telnet to a remote router using its loopback IP.
> But I wonder How I route
> as it always have the subnet mask of
> 255.255.255.255. Then which is the
> network and which the host
>
> Susan
>
_________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail at
> http://www.hotmail.com.
[EMAIL PROTECTED]
__________________________________________________
Do You Yahoo!?
Get personalized email addresses from Yahoo! Mail
http://personal.mail.yahoo.com/
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=9552&t=9493
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
