Hello, Le 22/01/2015 10:20, Chitrang Srivastava a écrit : > > I am new to SNMP world, and trying to set(SNMPv2c) an OID , which is of > type *DisplayString*, > > If string is huge like 1300 bytes or so , I see length in OID is encoded as > 1296 (0x0510) > > Byte stream I see on wire shark is like *0x04 0x82 0x05 0x10* > > Why is that ? Is this SNMP v2c limitation or something ASN.1 related?
I thing the answer is here : <http://en.wikipedia.org/wiki/X.690#The_definite_form>. <cit.> In contrast to the short form, the long form length octets consist of an initial octet and one or more subsequent octets. According to the X.690 standard [] the initial length octet shall be encoded as follows: bit 8 shall be one; bits 7 to 1 shall encode the number of subsequent octets in the length octets, as an unsigned binary integer with bit 7 as the most significant bit; the value 11111111 shall not be used. </cit.> After the 0x04 for OCTET STRING, you have 0x82 i.e. binary 10000010. The bit 8 is one, the bits 7 to 1 have value 2, i.e. two octets for the actual length. <cit.> All bits of the subsequent octets form the encoding of an unsigned binary integer equal to the number of octets in the contents octets. </cit.> 0x05 0x10, then 0x0510, i.e. 1296 decimal. Regards, -- Olivier Miakinen ------------------------------------------------------------------------------ New Year. New Location. New Benefits. New Data Center in Ashburn, VA. GigeNET is offering a free month of service with a new server in Ashburn. Choose from 2 high performing configs, both with 100TB of bandwidth. Higher redundancy.Lower latency.Increased capacity.Completely compliant. http://p.sf.net/sfu/gigenet _______________________________________________ Net-snmp-users mailing list Net-snmp-users@lists.sourceforge.net Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
