I'm not so sure that ARP is the appropriate term here. ARP is a defined
function within the TCP/IP suite. ARP is the means of resolving MAC
addresses to network addresses, usually on a broadcast medium such as
ethernet.
A router doesn't really "ARP" to determine which interface to send a packet
over. It does a table lookup. Also, ARP caches are subject to aging. Routes
in the routing table are not, subject to certain specifics for particular
protocols.
Remember too that routers can route things other than TCP/IP. IPX does not
have an ARP function for example, nor does it need one, since the MAC
address is part of the network address.
A router performs a very simple function, that being the forwarding of
packets, based on the routing table. How routes get into the routing table
is another story. the two ways I can think of are static definition and
routing protocols. Cisco's ODR might be considered a third means because it
is based on Cisco's proprietary CDP, which is a layer two protocol.
My point in asking the question originally was to provide a framework for
defining routing protocols versus routed protocols. A routed protocol is any
packet forwarded by a router based on routing table lookup. A routing
protocol is any protocol whose function is to exchange information of
network locations for purposes of placing this information into the routing
table.
In answer to Don's question earlier in the thread, can a router route
without a routing protocol in place, well, the answer is obvious, having
determined what routers do.
Chuck
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
EA Louie
Sent: Tuesday, July 10, 2001 7:04 PM
To: [EMAIL PROTECTED]
Subject: What is a router? [7:11857]
----- Original Message -----
From: Chuck Larrieu
[snip]
>
> To whit, what does a router do, and how does it do it?
>
It's a big ARP table, and it does it by associating network addresses with
an interface
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=11891&t=11857
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
