RFC 1879 (rfc1879) - Page 2 of 6
Class A Subnet Experiment Results and Recommendations
Alternative Format: Original Text Document
RFC 1879 Class A Subnet Experiment January 1996 Initial predictions [3] seemed to indicate that the safest path for an ISP that participates in such a routing system is to have -all- of the ISP clients be either: a) singly connected to one upstream ISP OR b) running a classless interior routing protocol It is also noted that a network with default route may not notice it has potential routing problems until it starts using subnets of traditional A's internally. Problems & Solutions Operations There were initial problems in at least one RIPE181 [4] implementation. It is clear that operators need to register in the Internet Routing Registry (IRR) all active aggregates and delegations for any given prefix. Additionally, there need to be methods for determining who is authoritative for announcing any given prefix. It is expected that problems identified within the confines of this experiment are applicable to some RFC 1597 prefixes or any "natural" class "A" space. Use of traceroute (LSRR) was critical for network troubleshooting during this experiment. In current cisco IOS, coding the following statement will disable LSRR and therefore inhibit cross-provider troubleshooting: no ip source-route We recommend that this statement -NOT- be placed in active ISP cisco configurations. In general, there are serious weaknesses in the Inter-Provider cooperation model and resolution of these problems is outside the scope of this document. Perhaps the IEPG or any/all of the national or continental operations bodies [5] will take this as an action item for the continued health and viability of the Internet. Manning Informational
