a 16MB cisco can't handle a "full internet route table" while a 16MB i486 machine can do it easily.
SL-IIJ-1>show ip b s BGP table version is 9430997, main routing table version 9430997 19216 network entries (32713 paths) using 2945880 bytes of memory 917 BGP path attribute entries using 73740 bytes of memory ... SL-IIJ-1>show mem free Head FreeList Total(b) Used(b) Free(b) Largest(b) Processor 310824 2E96D0 13315724 7699588 5616136 5131068 I/O 6000000 2F04B4 1047544 370708 676836 676836 SRAM 1000 2F11E8 65412 34760 30652 30652 SL-IIJ-1> show ver ... cisco 4000 (68030) processor (revision 0xA0) with 16384K/1024K bytes of memory. ... Cheers, -drc