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 ---------- ----------