I read that RIP-1 supports autosummarization and later in the book it says it does NOT support autosummarization. Which is correct?
RIPv1 is a classful routing protocol that doesn't carry subnet mask info.
It is obliged to perform auto-summary at major network boundary.
RIPv1 doesn't support to disable auto-summary.
RIPv2 supports it and allows for manual summarization out a specific interface RIPv1 cannot do this.
Hope to help