Please help: ptp links addresses
Dear Local Registries, I need some advice on the following: An italian ISP, which we run its delegated LIR, is planning its backbone network where there are *A LOT* of point-to-point links (on leased lines, on channelized lines, on Frame Relay PVCs, etc.). I know about two ways of managing the links in terms of IP addresses: 1- using a /30 subnet for each link: in this way both ends of the link have a unique address (binary 01 and 10), but two addresses (binary 00 and 11) cannot be used, so 50% of the address space used is wasted. This should be avoided if possible because the address space required is really large. 2- using unnumbered interfaces for each link and, on cisco routers, associating another interface IP address (the loopback interface is quite useful for this purpose): in this way addresses are not wasted but certain functionalities are lost, i.e. SNMP monitoring of each physical interface, etc. Are you aware of any other way to deal with this issue so that it is possible to have IP addresses for each interface without wasting address space? Thank you very much in advance. ---------- ---------- Antonio-Blasco Bonito E-Mail: bonito@nis.garr.it GARR - Network Information Service c=it;a=garr;p=garr;o=nis;s=bonito c/o CNUCE - Istituto del CNR Tel: +39 50 593246 Via S. Maria, 36 Fax: +39 50 904052 I-56126 PISA Telex: 500371 CNUCE I Italy Url: http://www.nis.garr.it/nis/staff/bonito.html ---------- ----------
1- using a /30 subnet for each link: in this way both ends of the link have a unique address (binary 01 and 10), but two addresses (binary 00 and 11) cannot be used, so 50% of the address space used is wasted. This should be avoided if possible because the address space required is really large.
The usage is actually 75%, as there are effectively three addresses: the two ends (00 and 01) and the broadcast address for the network (11). 10 is the unused address. Mike
On Tue, 25 Jun 1996, Antonio_Blasco Bonito wrote:
I need some advice on the following:
An italian ISP, which we run its delegated LIR, is planning its backbone network where there are *A LOT* of point-to-point links (on leased lines, on channelized lines, on Frame Relay PVCs, etc.).
I know about two ways of managing the links in terms of IP addresses:
1- using a /30 subnet for each link: [...]
2- using unnumbered interfaces for each link and, on cisco routers, associating another interface IP address (the loopback interface is quite useful for this purpose): in this way addresses are not wasted but certain functionalities are lost, i.e. SNMP monitoring of each physical interface, etc.
Are you aware of any other way to deal with this issue so that it is possible to have IP addresses for each interface without wasting address space?
Hmm... I tried to do the following... it makes a bit sense to me, but my Cisco didn't like it (makes more sense if it rfc1918 address space). I took a quick glance at RFC1812 as well, but it didn't give a solution. interface s0 ip unnumbered e0 ip addr 193.88.45.1 255.255.255.252 secondary What happened though, was that the traffic looped between the two interfaces. What would be the good about this solution was that on a traceroute it would still map back to a host in your domain, but you can still ping/SNMP to the interface. So if someone has a good contact at Cisco, please ask them if they'd consider adding this to the code in the future. :-) -- Robert Martin-Legène (RM59), Network Manager (AS2109) DKnet, Fruebjergvej 3, DK-2100 København Ø, Denmark, +45 39 17 99 00
Estimado/a Sr/a, Su mensaje de fecha: Mon, 8 Jul 1996 20:36:12 +0200 (MET DST) acerca de: Re: Please help: ptp links addresses ha sido recibido satisfactoriamente en el help-desk del ES-NIC (nic@rediris.es). El numero de mensajes pendientes de procesar en estos momentos es de 312. El suyo sera procesado cuando le llegue su turno, que estimamos sera en 20 dias habiles. Por favor, le rogamos encarecidamente que no vuelva a enviar su mensaje (en ese caso el recibido en primer lugar sera ignorado). Si lo que desea es informacion acerca del procedimiento y formulario para registrar un dominio de DNS de segundo nivel bajo ".es", puede obtener la documentacion necesaria en: ftp://ftp.rediris.es/es-nic/es-nic-dom.txt o bien enviando un mensaje a nic@rediris.es cuyo "subject" sea: get es-nic-dom.txt Si lo que desea son direcciones IP Internet, pongase en contacto con su proveedor de acceso Internet, que es quien se las tiene que suministrar (con fecha 31/1/96 el ES-NIC ha dejado de ejercer las funciones de registro de ultimo recurso para la asignacion de direcciones IP en Espana). Los proveedores, a su vez, han de obtener las direcciones IP necesariamente bien de su proveedor de transito, bien del registro delegado de Internet en Europa (RIPE NCC). Si es para cualquier otro asunto, recibira contestacion cuando su mensaje sea procesado. En caso de tratarse de una solicitud de registro de nombre de dominio bajo "es" le recordamos algunas de las normas basicas: - Solo se puede registrar un dominio de segundo nivel por organizacion, entendiendo como tal una persona juridica (no fisica), es decir, una entidad legalmente establecida en Espana y, por tanto, registrada en algun registro oficial (mercantil, fundaciones, asociaciones, entidades publicas, partidos politicos, etc.) - El dominio propuesto habra necesariamente de corresponderse o ser directa y facilmente asociable al nombre con el que la organizacion aparece registrada en el mencionado registro oficial (preferentemente el nombre completo o un acronimo registrado y habitualmente usado por la organizacion). - En el caso de que la organizacion prefiera utilizar el nombre de una de sus marcas registradas con la que habitualmente se la identifique, en lugar del de la propia organizacion, podra solicitar el registro de un nombre de dominio que se corresponda con dicha marca, siempre que lo acredite mediante el envio a este NIC del certificado correspondiente de la Oficina Espanola de Pantentes y Marcas. - Los unicos caracteres validos para un nombre de dominio son las letras del alfabeto ingles, los numeros y el guion ("-"). - En nigun caso se admitiran solicitudes de registro de nombres de dominio que: a) tengan menos de tres caracteres b) coincidan con algun dominio de DNS de primer nivel (Top Level Domain) c) se compongan exclusivamente de un toponimico d) se compongan exclusivamente de un generico e) coincidan con nombres de protocolos, aplicaciones y terminologia de Internet f) sean contrarios a la Ley o el orden publico, ofensivos o malsonantes g) se compongan exclusivamente de una combinacion de c), d), e) o f) h) se asocien de forma notoria a otra organizacion distinta de la solicitante i) se compongan exclusivamente de nombres o apellidos - Las solicitudes se procesaran por estricto orden de llegada. - Toda solicitud incorrecta, incompleta o que no cumpla las normas sera rechazada. - Cualquier falsedad en los datos consignados en la solicitud podra ser causa de rechazo de la misma o de baja del dominio si el registro ya se hubiera producido. Atentamente, ES-NIC +---------------------------------------------------------------+ | ES-NIC (Delegated Internet Registry for Spain) | | Centro de Comunicaciones CSIC RedIRIS | | Serrano 142 Tel: + 34 1 5855150 | | 28006 Madrid Fax: + 34 1 5855146 | | SPAIN Email: nic@rediris.es | +---------------------------------------------------------------+
This is an automatic reply to acknowledge that your message has been received by the Greek Hostmaster (hostmaster@forthnet.gr) This acknowledgement is NOT a confirmation that your request has been processed. Your mail was forwarded to the appropriate people and you will have a response to your request as soon as possible. Kind regards, GR-HOSTMASTER hostmaster@forthnet.gr
Why not use "private" address space, like network 10.0.0.0 You'll have plenty of subnets for internal links ! Regards, ___ ___ __ /__/ / /__/ / /\ / / / /__ / / _/_ / \/ o vox://+972-4-8560600 cel://+972-5-2593886 Alain@NetVision.net fax://+972-4-8550345 http://www.netvision.net.il/php/alain
On Tue, 9 Jul 1996, Alain Golan wrote:
Why not use "private" address space, like network 10.0.0.0 You'll have plenty of subnets for internal links !
Because the address of the router in a traceroute then might be private address space one. I sort of like the idea that you know where in the world you are when you do a traceroute. If the interface has a hidden IP# that you can send packets to, but it still will present itself as (for instance) the ethernet interface, you just give the ethernet interface a "normal" IP# and all looks normal and the router only takes up one IP# (not counting RFC1918 address space). This way you can still ping the interface on 10.0.0.1 . -- Robert Martin-Legène (RM59), Network Manager (AS2109) DKnet, Fruebjergvej 3, DK-2100 København Ø, Denmark, +45 39 17 99 00
Robert Martin-Legene <robert@DK.net> writes:
Because the address of the router in a traceroute then might be private address space one. I sort of like the idea that you know where in the world you are when you do a traceroute.
While this is nice but there may be a tradeoff here. If the address space for links and router interfaces is used efficiently, this is very nice to have. However some people for convenience or other reasons want to burn a lot of address space inefficiently -/24 subnets for 2 interfaces come to mind. In this case they are welcome to use private address space. One of the prices they pay is the tradcerooute problem; another is that they are not able to address spaceific interfaces directly from the Internet. Some tell us that this is a feature and not a bug ;-). As always there is no answer/soloution that fits everyone. Also note that even for private address space traceroute will return the address correctly, so the diagnostics are useful. There just are no names. If the border gateways with publicly adressed interfaces has a reasonable name such as 'bordergw-xxx.clever.net' 'clever-gw.customer.nl' it is quite clear "where you are" in between.
If the interface has a hidden IP# that you can send packets to, but it still will present itself as (for instance) the ethernet interface, you just give the ethernet interface a "normal" IP# and all looks normal and the router only takes up one IP# (not counting RFC1918 address space) This way you can still ping the interface on 10.0.0.1 .
I am not sure I grok that. Daniel
participants (7)
-
Alain Golan -
Antonio_Blasco Bonito -
Daniel Karrenberg -
GR HostMaster -
Mike Norris -
Network Information Centre. RedIRIS CSIC -
Robert Martin-Legene