announce address for the local network

[Joachim]

Hallo,
I am wondering if anybody could help me to explain the fifth line in
the following routing table:

Network Address Netmask Gateway Address
0.0.0.0 0.0.0.0 205.217.146.1
127.0.0.0 255.0.0.0 127.0.0.1
205.217.146.0 255.255.255.0 205.217.146.200
205.217.146.200 255.255.255.255 127.0.0.1
205.217.146.255 255.255.255.255 205.217.146.200
224.0.0.0 224.0.0.0 205.217.146.200
255.255.255.255 255.255.255.255 205.217.146.200

The first line is the default route for everything not mentioned
elsewhere.
The second line is the local host.
The third line is the local network direct connected to the PC.
The fourth line is the PC itself.
The fifth line is a broadcast address ???
(Means that any broadcasts should be send to 205.217.146.200 ?)
Is that line really needed? When is it needed?
Is it needed for the arp protocol?

Any comments to my question are appreciated.
Joachim

[News Reader]

Joachim wrote:
> Hallo,
> I am wondering if anybody could help me to explain the fifth line in

Lines 3, 5, 6, and 7 all convey the same format (Gateway Address).

> the following routing table:
>
> Network Address Netmask Gateway Address
> 0.0.0.0 0.0.0.0 205.217.146.1
> 127.0.0.0 255.0.0.0 127.0.0.1
> 205.217.146.0 255.255.255.0 205.217.146.200
> 205.217.146.200 255.255.255.255 127.0.0.1
> 205.217.146.255 255.255.255.255 205.217.146.200
> 224.0.0.0 224.0.0.0 205.217.146.200
> 255.255.255.255 255.255.255.255 205.217.146.200
>
> The first line is the default route for everything not mentioned
> elsewhere.
> The second line is the local host.
> The third line is the local network direct connected to the PC.
> The fourth line is the PC itself.

Reached via the loopback interface. Packet NOT required to be placed on
the wire.

> The fifth line is a broadcast address ???

Reached via a connected route. The packet is required to be placed on
the wire, via a specific interface.

> (Means that any broadcasts should be send to 205.217.146.200 ?)

Perhaps this just conveys that the destination is directly reachable by
the host itself (205.217.146.200), without the aid of a router (i.e.: a
connected route).

If you had more than one NIC with an assigned IP address, this might
help convey which NIC to use to get to a specific destination. Although,
that does seem a bit redundant given that there is an "interface" column
in the route table (at least on my host).

> Is that line really needed? When is it needed?
> Is it needed for the arp protocol?

Would be needed for any communication, not just ARP.

>
> Any comments to my question are appreciated.
> Joachim
>

Best Regards,
News Reader