Internet Protocol Network Multipathing (Update)
This article is an update to the article published in August 2001. It has been updated primarily because of Bug ID: 4710499, "Synopsis: rpc.bootparamd cannot send out reply with physical interface flag DEPRECATED." More details on this are presented later in this article and from http://sunsolve.sun.com/. This article also removes the reference to a dummy data address, this is now termed an additional data address. This is to avoid any confusion. While the address might not be used for inbound connections if it has not been advertised in a naming service or otherwise published. It will be utilized for outbound network connections. This additional address was originally included to circumvent a problem, Bug ID: 4426000, that could occur on boot with Solaris_ 8 Operating Environment (Solaris 8 OE) systems. This problem has been fixed in Solaris 9 OE.
This article describes the features and configuration of Internet Protocol network multipathing (IPMP). IPMP can provide network adapter resilience and increased data throughput by using multiple network adapters connected to the same subnet.
The intended audience for this article is systems designers or administrators. This article is a concise overview of the Solaris 8 OE IP Network Multipathing Administration Guide documentation. The following elements are addressed:
- Design Considerations
- Basic Management
This article also discusses two essential considerations for IP network multipathing that are not covered in the administration guide. See sections, Data Address Definition within the Design Considerations section and the addendum, The Problem With ping.
This article covers the IPv4 network protocolsfor information on IPv6, see the IP Network Multipathing Administration Guide section of the Solaris 8 OE documentation. Go to: http://docs.sun.com/
The commands of IP network multipathing are not listed in the man pages of the Solaris OE version 8 update 2 (10/00), but are in later releases.
IP network multipathing was introduced in the Solaris 8 OE update 2 (10/00) software release. This feature enables a server to have multiple network ports connected to the same subnet.
Network adapters function in the following modes:
IP network multipathing coupled with multiple network connections per subnet provide a server with one or both of the following advantages:
- Resilience from network adapter failure
- Increased data throughput for outbound traffic
To provide resilience, IP network multipathing detects the failure or repair of a network adapter, and switches the network address to or from an alternative adapter. If more than one network adapter is active, outbound packets are spread across adapters, thereby increasing data throughput.