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Reading about IP Routing, I found a brief explanation: "routing daemon, which is normally a user process. The most common daemons used on Unix systems are the programs routed and gated."

In an Unix system these programs are activated if an host to act as router. So, routing daemon is not applied in Cisco IOS? If I am right, those two little square "Routing Daemon" "Netstat Command" are replaced by one routing protocol? Sure which will not exists TCP Module too

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  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide your own answer and accept it. – Ron Maupin Aug 6 '17 at 20:42
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The picture you show is a logical diagram that shows functional elements. As such the functions within it may or may not be implemented as separate software processes, threads, daemons, etc. UNIX and its variants tend to implement the boxes in the picture as processes. Thus you have the netstat command to view the routing table and the route command to update it.

You may also have a routing daemon (long running server process) to take care of updating the routing table without requiring manual intervention via the route command. In the vast majority of servers there is a limited number of routes needed so it is just as efficient to set up the routing table by hand and dispense with a routing daemon. But for those that do, they can run a daemon. The name of the daemon varies according to the routing update and distribution protocol that is in use. For example, routed for RIP, bgpd for BGP.

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You can't compare a monolithic, closed, proprietary OS like IOS to any other OS since you have no architectural or other reference points with which to compare. There may be similarities, but the people who know aren't talking due to legal issues.

Routing works at layer-3, mostly with IP in today's world, but not exclusively. TCP, UDP, etc. are at layer-4. Routing uses the layer-3 addresses to populate a routing table which it uses to switch layer-3 packets from one interface to another.

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  • Of course, but Are Routing Daemons exclusive in Unix systems? Basically, It is employing a function of routing protocol, once that it provides updates in the kernel routing table.. Right? – TMoraes Sep 29 '15 at 0:35
  • The various *nix OSes use daemons. I'm not sure they all have a routing daemon, but most all probably do because of the Unix heritage. Not all OSes are so modular, and some which are not may or may not have services or applications that do routing. There are certainly OSes that have no such routing functionality unless someone has written an application for it. You really need to ask such a question about a specific OS. – Ron Maupin Sep 29 '15 at 0:42
  • I checked in my Unix OS, I've not anyone of three Routing Daemons kinds, I belive which is necessary active them. I am sorry about this specific question, I was looking for a diagram which shown the Layer IP of a Router. – TMoraes Sep 29 '15 at 0:53
  • Again, I belive which must not change to much, rather of Routing Daemon or Netstat, has a routing protocol and sure without TCP Module – TMoraes Sep 29 '15 at 0:55
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    TCP is a layer-above the routing layer. The only routing protocol that I know about that uses TCP is BGP which establishes a TCP session between neighbors. – Ron Maupin Sep 29 '15 at 0:58
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On unix-like operating systems the term "daemon" refers to a long running program that performs some service. Generally started by the systems startup scripts and stopped by it's shutdown scripts.

A routing daemon is a daemon that implements a routing protocol. It sends and receives routes from other routers and uses them to update the routing table in the kernel.

I do know know (and it may well be a secret) exactly how things are broken down on propietary routers but there will almost certainly be a split between the buisness of managing what routes are in use and the buisness of actually forwarding packets based on those routes.

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