Bringing AgentX Subagents to the Operating System Kernel Space
SNMP agents on conventional operating system platforms are mostly monolithic and implement Managed Objects in a single program. The concept of subagents makes it possible to delegate the implementation of Managed Objects to several subagents located close to the managed subsystems. All subagents are managed by a master agent. While this concept is well accepted for hardware subsystems of modular devices and for host services running in the user space, it is not yet applied for components of conventional operating systems.
This paper examines to what extent the IETF standard subagent protocol AgentX is suitable for the management of kernel components. For this purpose, on the Linux platform two subagents have been implemented within the kernel subsystems they manage. They communicate with a master agent in user space. The implemented software contains a generic intermediate layer which carries out AgentX protocol operations and access to Managed Objects. Based on this layer, the network interface subsystem and the Netfilter subsystem have been enhanced with management extensions.
KeywordsProtocol Layer User Space Kernel Space Network Address Translation Simple Network Management Protocol
- 1.The NET-SNMP home page. WWW Page, http://www.net-snmp.org
- 2.Carpenter, G., Wijnen, B.: SNMP-DPI: Simple Network Management Protocol Distributed Program Interface. RFC 1228, T. J. Watson Research Center, IBM Corp. (May 1991)Google Scholar
- 3.Case, J., Mundy, R., Partain, D., Stewart, B.: Introduction to Version 3 of the Internet-standard Network Management Framework. RFC 2570, SNMP Research, TIS Labs at Network Associates, Ericsson, Cisco Systems (April 1999)Google Scholar
- 4.Daniele, M., Wijnen, B., Ellison, M., Francisco, D.: Agent Extensibility (AgentX) Protocol Version 1. RFC 2741, Digital Equipment Corporation, IBM T. J. Watson Research, Ellison Software Consulting, Cisco Systems (January 2000)Google Scholar
- 5.Eyler, P.: Networking Linux: A Practical Guide to TCP/IP. New Riders Professional Library (2001)Google Scholar
- 6.McCloghrie, K., Kastenholz, F.: The Interfaces Group MIB. RFC 2863, Cisco Systems, Argon Networks (June 2000)Google Scholar
- 7.Rose, M.: SNMP MUX Protocol and MIB. RFC 1227, Performance Systems International (May 1991)Google Scholar
- 8.Strauß, F., Schönwälder, J., Mertens, S.: JAX - A Java AgentX Subagent Toolkit. In: Proc. 1st IEEE Workshop on IP-oriented Operations & Management, Cracow (September 2000)Google Scholar
- 9.Strauß, F., Wellnitz, O.: The experimental TUBS-IBR Linux Netfilter MIB. TUBS-IBR-LINUX-NETFILTER-MIB (2002), http://www.ibr.cs.tu-bs.de/arbeiten/strauss/kagentxd/
- 10.Wehrle, K., Pählke, F., Ritter, H., Müller, D., Bechler, M.: Linux Network Architecture. Prentice Hall, Englewood Cliffs (2004)Google Scholar
- 11.Wijnen, B., Carpenter, G., Curran, K., Sehgal, A., Waters, G.: Simple Network Management Protocol Distributed Protocol Interface Version 2.0. RFC 1592, IBM T. J. Watson Research Center, Bell Northern Research Ltd. (March 1994)Google Scholar