Posted by: Sandesh Dixit on: October 7, 2008
You use GETNEXT, typically, to get selected columns from one or more rows of a table. If you want the values for columns S(1)..S(s) from columns C(1)..C(c) (where s<c (and there are N rows), you would make N+1 GETNEXT requests. (This assumes that the varBinds for columns S(1)..S(s) will fit in a request and response [...]
Posted by: Sandesh Dixit on: October 7, 2008
SNMPv2 had been announced for many months, and most of us assumed that it was accepted as the next step up from SNMPv1. That assumption was false. In fact there were several points on which the members of the IETF subcommittee could not agree. Primary among them was the security and administrative needs of the [...]
Posted by: Sandesh Dixit on: October 7, 2008
In the SNMPv1 protocol, there is a single type of operation to send an unsolicited message from an agent to a manager, which is a [v1]Trap. SMIv1 uses the TRAP-TYPE construct to define the conditions when such a message can be generated, the identification of the message, and the management information to be contained in [...]
Posted by: Sandesh Dixit on: October 7, 2008
I am relatively ignorant about SNMP. However, I have spent a reasonable amount of effort investigating agents, managers, the technology, and I have read most of the important RFCs. There are a bunch of related but simple, practical questions to which I cannot get a straight answer: Are SNMP traps useful in the real world? [...]
Posted by: Sandesh Dixit on: October 7, 2008
“Automated topology discovery is a hard problem due to the diversity of deployed systems and the wide distribution of resource information. I will briefly mention some reasons why a ping/traceroute based approach will not work : subnetting, tunneling, firewalls, virtual LANS. Your network topology discovery tool would have to extract more information like subnet masks, [...]
Posted by: Sandesh Dixit on: October 7, 2008
There are several varients of the SNMPv2 protocol. They are: SNMPv2p(OBSOLETE): For this version, much work was done to update the SNMPv1 protocol and the SMIv1, and not just security. The result was updated protocol operations, new protocol operations and data types, and party-based security from SNMPsec. This version of the protocol, now called party-based [...]
