Comments inline: *-----Original Message----- *From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED]] *Sent: Tuesday, July 16, 2002 1:32 PM *To: [EMAIL PROTECTED] *Subject: Re: ip unnumbered [7:48894] * * *Chuck wrote: *> *> recall that the link between you and whomever is a two host *> network. * *And I would add to that, recall that the link is just a transit for *end-to-end traffic. With the exception of network management, *it doesn't *matter what the network-layer addressing is on that link. It carries *host-to-host traffic which is identified by the network-layer *addresses of *the end hosts. * *What I'm trying to get at is that you may be concerned because *of a common *misconception that the network-layer addressing changes from *hop-to-hop, *which it doesn't. (If you're studying for CCIE, then of course *you wouldn't *have that micsonception, but I don't know how far you are in *your studies *yet. :-) * *Now, network management is a concern, however. If your serial *interface is *unnumbered, you can't ping it or send it SNMP messages. With those *functions, the serial port acts as an end host and must have a *network-layer *address. That's the tradeoff. As Chuck says, it's common *practice to use *unnumbered with static and default routing pointing to the interface, *however. So many people take the tradeoff. Even though you *can't ping the *serial interface, you can still get a lot of info from it with the show *interface command.
As Priscilla states, a ping monitor wouldn't work for the serial interface, but you can still poll the router via SNMP using a loopback or other interface network layer address for the status of the unnumbered interface. So if your monitoring system is using the output of the SNMP interface status, you can still monitor the interface. * *________________________ * *Priscilla Oppenheimer *http://www.priscilla.com * * * *> if you *> were numbering, you would most likely use a /30. even when *> connecting to the *> internet, this link need not use public IP space. Your ISP is *> most likely *> using a static route to you, and you in turn are using a static *> route to *> them. *> *> them: ip route "your public space" out interface X *> *> You: ip route 0.0.0.0 0.0.0.0 interface Y *> *> this is a regular practice. *> *> IP unnumbered is even better, because then no one has to commit *> to or agree *> upon address, and no one has to waste public space. *> *> Usually, you would number your ethernet port with a public *> number, and you *> would use an ip unnumbered off that publicly addressed *> interface. *> *> HTH *> *> *> *> ""richard dumoulin"" wrote in message *> [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... *> > Hey guys, *> > I have to connect a Cisco router to the internet (Worldcom) *> and I was told *> > the following "If your router is a CISCO model, then there is *> no *> > need to assign actual IP addresses to the WAN serial *> > interfaces since CISCO's un-numbered technology can *> > be employed". Does this mean that I can configure IP *> unnumbered ethernet0 *> or *> > loopback0 (with one of them having a routable IP address) and *> so I must *> > configure ppp encap on the serial ?? *> > *> > I am a bit confused, thx for your help !! *> *> * * * * Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=48942&t=48894 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
