Re: subnet mask of /32

James <j@[EMAIL PROTECTED]
> wrote in news:g29knc$cnu$1$8302bc10@[EMAIL PROTECTED]
> I have seen on some ISPs an IP address and a subnet mask of 
> 255.255.255.255 (/32)
> 
> I'm a little confused of this as one needs a default gateway. The 
> default gateway of this network would be???
> 
> This to me is a network address and broadcast address, so I'm not sure 
> how to understand this.
> 
> Does anyone have a proper explanation of this?
> 
> Regards
> 
> James
> 

Hi James

This type of IP address is often known as a loopback address, normally 
issued to a loopback interface on your router for management purpose. The 
router announces the particular IP address via its routing protocol to 
other routers. Actually some routing protocols demand such an IP address 
on a loopback for proper functionallity.

A loopback interface is actually a virtual interface on the router, that 
never goes down unless you explicit do a shutdown on the interface.

Regards,
Lars Christensen
CCIE #20292