Re: assumption about number of octets encoding PENs

Hi -

> From: "David Harrington" <[email protected]>
> To: "Romascanu, Dan (Dan)" <[email protected]>; "Mark Ellison" <[email protected]>
> Cc: "Alan DeKok" <[email protected]>; <[email protected]>; <[email protected]>
> Sent: Wednesday, May 23, 2012 8:06 PM
> Subject: Re: [OPS-AREA] assumption about number of octets encoding PENs
...
> A PEN is defined as being an OBJECT IDENTIFIER (a sub-oid if I read
> RFC1157 correctly).
> I think that means the number range is constrained by the adapted subset
> of 1988 ASN.1 that defines an INTEGER sub-oid.
> But I don't have time right now to research that limit.

In ASN.1 the range for sub-oids isn't tied to the definition of the
INTEGER type.  In ASN.1 no upper bound is mandated for sub-ids, other
than in the first position and in the second position if the first is a 0 or 1,
due to the way BER mashes them together.

RFC 1157 also didn't specify limits for sub-identifiers.  Some early
SNMP implementers responded to this by writing their code to 
handle well-formed subidentifiers larger than 0xFFFFFFFF.
I ran into one very early SNMP implementation that had problems
handling subidenfiers greater than a measly 0xFFFF. 

Randy