compare layer of RIP vs. OSPF

Hello

Every one knows that RIP and OSPF protocols are routing protocols.
My question is the difference between them.

RIP uses UDP port 520.
This means that RIP format in the network layer has following shape.

+---------------+----------------+-----------------------+
| IP header | UDP header | RIP header |
+---------------+----------------+-----------------------+

However
OSPF is directly attached next to the IP header like

+---------------+-----------------+
| IP header | OSPF header |
+---------------+-----------------+

Both protocols have similar functions like routing.
Why does RIP use UDP header, OSPF does not use UDP header?

Choonho wrote:
> Hello
>
> Every one knows that RIP and OSPF protocols are routing protocols.
> My question is the difference between them.
>
> RIP uses UDP port 520.
> This means that RIP format in the network layer has following shape.
>
> +---------------+----------------+-----------------------+
> | IP header | UDP header | RIP header |
> +---------------+----------------+-----------------------+
>
> However
> OSPF is directly attached next to the IP header like
>
> +---------------+-----------------+
> | IP header | OSPF header |
> +---------------+-----------------+
>
> Both protocols have similar functions like routing.
> Why does RIP use UDP header, OSPF does not use UDP header?

The IP header carries all the needed info, ie., OSPF does not need the
port numbers added by a UDP header.

Specifically, the IP PROTOCOL field for OSPF is 89. RIP has no
specific protocol field reserved for its use; it uses UDP (PROTOCOL
field is 17).

See:
http://www.networksorcery.com/enp/pr...p.htm#Protocol

hth,
prg

Thank you for your apply.

I also know that OSPF has a protocol number in the IP header, but RIP does
not.
I want to know a historical reason why RIP does not have a protocol number
in the IP header.

"prg" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
>
> Choonho wrote:
>> Hello
>>
>> Every one knows that RIP and OSPF protocols are routing protocols.
>> My question is the difference between them.
>>
>> RIP uses UDP port 520.
>> This means that RIP format in the network layer has following shape.
>>
>> +---------------+----------------+-----------------------+
>> | IP header | UDP header | RIP header
>> |
>> +---------------+----------------+-----------------------+
>>
>> However
>> OSPF is directly attached next to the IP header like
>>
>> +---------------+-----------------+
>> | IP header | OSPF header |
>> +---------------+-----------------+
>>
>> Both protocols have similar functions like routing.
>> Why does RIP use UDP header, OSPF does not use UDP header?
>
> The IP header carries all the needed info, ie., OSPF does not need the
> port numbers added by a UDP header.
>
> Specifically, the IP PROTOCOL field for OSPF is 89. RIP has no
> specific protocol field reserved for its use; it uses UDP (PROTOCOL
> field is 17).
>
> See:
> http://www.networksorcery.com/enp/pr...p.htm#Protocol
>
> hth,
> prg
>

Choonho wrote:
> Thank you for your apply.
>
> I also know that OSPF has a protocol number in the IP header, but RIP does
> not.
> I want to know a historical reason why RIP does not have a protocol number
> in the IP header.

Hmmm ...
That is an interesting question to which I wish I could offer a good
answer with many adventurous tales. Alas, no such luck.

He's my best speculation.

Long before RIP was formalized, routed was being used as a routing
protocol. In effect, routed defined the RIPv1 protocol by default.

UDP was used to avoid the overhead of TCP and a separate IP protocol
type was not an option. You don't just go out and make your own IP
protocol types. Applications, like routed, are not limited in that
fashion and only need a "well known" port to run on.

OSPF was designed _before_ it was implemented and put in use widely.
The designers used the option to request and get an IP protocol type
assigned to them. Why this instead of UDP?

Overhead efficiency and flexibility are my candidates for an answer.
Why waste time passing through UDP?

sorry, that's the best I can do ...
prg

> "prg" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed) oups.com...
> >
> > Choonho wrote:
> >> Hello
> >>
> >> Every one knows that RIP and OSPF protocols are routing protocols.
> >> My question is the difference between them.
> >>
> >> RIP uses UDP port 520.
> >> This means that RIP format in the network layer has following shape.
> >>
> >> +---------------+----------------+-----------------------+
> >> | IP header | UDP header | RIP header
> >> |
> >> +---------------+----------------+-----------------------+
> >>
> >> However
> >> OSPF is directly attached next to the IP header like
> >>
> >> +---------------+-----------------+
> >> | IP header | OSPF header |
> >> +---------------+-----------------+
> >>
> >> Both protocols have similar functions like routing.
> >> Why does RIP use UDP header, OSPF does not use UDP header?
> >
> > The IP header carries all the needed info, ie., OSPF does not need the
> > port numbers added by a UDP header.
> >
> > Specifically, the IP PROTOCOL field for OSPF is 89. RIP has no
> > specific protocol field reserved for its use; it uses UDP (PROTOCOL
> > field is 17).
> >
> > See:
> > http://www.networksorcery.com/enp/pr...p.htm#Protocol
> >
> > hth,
> > prg
> >