Would have been nice if someone actually put it that way... all responses seemed to be confused as to what I was wanting to do until I put in the form of my last reply.
Thanks for the input. Mark -----Original Message----- From: Tshon [mailto:[EMAIL PROTECTED]] Sent: Thursday, March 14, 2002 4:11 PM To: Mark Odette II Cc: [EMAIL PROTECTED] Subject: Re: Loopback Interfaces..long reply, read carefully please to [7:38285] The answer everyone keeps giving you is no. Mark Odette II wrote: OK, For some reason, my first time of sending this reply got chopped, sohere it is again.Brian, et al.,Please Note the following:***All I wanted to know was: Can the Loopback Interface be used to host acomplete subnet (and the Router make routing decisions with this inteface),or is its functionality such that it will always respond like an interfaceconfigured with a 255.255.255.255 mask, and 86 traffic not destined for ITon the same subnet??I'm not looking for someone to help me make a completely working config forall routers in this implementation.The idea is to do such:!Interface FastEthernet0! description Connected to PIX Outside Interface, and PIX Inside Interfaceis subnet for Data traffic.! Ip adress x.x.x.x 255.255.255.x!Interface Loopback0! description VoIP subnet with VoIP originating/terminating on thisRouter... other hosts also placed on the same subnet at a later date, andconnecting via the Ethernet Port which connects to a switch that the otherhosts are also plugging into.! Ip address 192.168.101.1 255.255.255.0!Interface Serial0! NO IP ADDRESS! Encap Frame-Relay!Interface Serial0.1! description Connected to the Internet! Ip address x.x.x.x x.x.x.252! interface-dlci 16!Interface Serial0.100! description Connected to HQ over PVT FR for Voice traffic! ip unnumbered loopback0! interface-dlci 100! {insert Map-Class Tag here}!{Insert Route-Maps Here}!{Insert Voice configuration here... a.k.a. Dial Peers}!{Insert QoS config here... a.k.a. Map Classes}!Router EIGRP 1750!Network 192.168.100.0 >>Brian""Mark Odette II"" wrote in message[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... OK, I'll make the question simpler.Can you use a loopback interface in the same respect that you would use anethernet interface?Create the loopback: Interface Loopback0Assign it an IP with a /24 mask : ip address 192.168.10.1Configure the subnet assigned to the loopback interface to a routingprocess, such as EIGRP or RIP.Assign many other hosts on a LAN or a WAN an IP address that is in the same subnet as the loopback interface.Replicate the above configuration on Router at other end of FR network.add subnet assigned to far-end routers' loopback interface to local EIGRPAS, or RIP; do the same on the far-end routers' config for the same EIGRP AS or RIP configuration.And then, configure FR Subinterface with IP Unnumbered Loopback0, and route traffic across the FR network, with the traffic orininating from either the Router, or another host (if configuration above is legal) on the subnet that is assigned to the Loopback interface.What I want to do, is configure a VoIP enabled router with a loopbackinterface assigned to 192.168.10.1, and several LAN hosts with the samesubnet assignment, i.e., 192.168.10.2, .3, .4, etc., and a /24 subnet maskfor all hosts including loopback interface.I then want to create and assign IP Unnumbered loopbackX to a FR P-to-Psubinterface.Create EIGRP AS to route Subnets assigned to loopback interfaces on eachrespective router.Mirror image this configuration on the other end of the "wire" (FR Network). Configure Dial-Peers with VOIP destinations pointing to the loopbackinterface of the peer router (other end of the FR Network).Is this Possible??The reason why I want to use Loopback interfaces, is because I plan toassign a separate subnet to the FastEthernet Interface, and don't believethat the use of the Secondary command will work, i.e., you can't specify IP Unnumbered FastEthernet0 and have the Secondary IP address used.... ipunnumbered fastethernet0 will use the FastEthernets' Primary address, which is not desired.The Primary Subnet assigned to the FastEthernet Interface will be NATTranslating with a PIX FW (PIX will be doing the NAT) to hit the Internet.For Topology description:Router HQ connects to internet on one subinterface, while connecting to 3remote offices on a private FR network on a second subinterface.Router Remote1 Will be connecting to the internet on one subinterface, while connecting back to HQ on separate FR subinterface for VoIP over FR trafficonly (no Data traffic)Router Remote2 will be doing the same as Remote1Router Remote3 will also be doing the same as Remote1... So much for a simpler reply. :)Thanks in advance for everyones' comments.-----Original Message-----From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf OfTshonSent: Tuesday, March 12, 2002 11:44 PMTo: [EMAIL PROTECTED]: Re: Loopback Interfaces... [7:37933]What in the world is the question about, what are you trying to do. Ping the remote routers, they have a serialinterface that you can ping, or the ethernet. Why do you need aloopback, what routing protocol are yourunning, where is a config? We can't figure out what you are talkingabout, we need your help to help you.Brian Lodwick wrote: This has got to be the most confusing message I have ever read.A loopback interface is just a virtual interface. It's not a real interface it's just a virtual interface you can create within the router, and you can create as many as you want.The biggest reason someone would want to use a loopback interface would be for resiliency. If you build a certain session to the loopback interface(BGP, DLSW...) and you have more than one path to reach this router thesession will not die if a certain interface dies. ___________ ( )------- r1 >>Brian""Mark Odette II"" wrote in message[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... Just when I thought I understood Loopback interfaces, I decided whileredesigning a network, that I would use them.... but now I'm questioning my comprehension.Somebody clear the confusion for me- Please.This is what I'm wanting to do, but not sure if this is proper utilization, much less whether or not it will work:RouterHQ connecting to 3 Remote Routers (branch offices) via FR Pvt Network RouterHQ has 2 Ethernet Interfaces, but the Remotes Do NOT....They only have one.(I think without pause: "No Problem, I can just create a Loopback interface to take care of the other subnet.")The FR Pvt Network is only for Voice Traffic, while all data traffice will be going out another interface that is using IP UnNumbered InterfaceFastEthernet0.Here is where my quandry lays. I can't create a Secondary address, as Ibelieve the IP UnNumbered command will use the primary address on theEthernet Interface.So, can I create a Loopback interface, and treate it like a Ethernetinterface, as such that I can assign an IP to the Loopback interface, but it have a /24 mask, and other devices on the local network can also be keyed for the same subnet as the Loopback, making it where I can give the command IP UnNumbered Lo0 to a Serial SubInterface??I thought I could, but then got concerned when I hopped on CCO, and did a lookup on Loopback interfaces, and read a blurb about traffic NOT destined for the LoopBack Interface itself will be routed to 'ye old trashcan' i.e., Null Interface.Somebody please tell me that I can send traffic from one end of the circuit to the other and have it destined for a node OTHER than the LoopbackInterface with that node being on the same subnet as the Loopback interface. Thanks.Mark Message Posted at:http://www.groupstudy.com/form/read.php?f=7&i=38285&t=38285-------------- ------------------------------------FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.htmlReport misconduct and Nondisclosure violations to [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=38317&t=38317 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
