GbE2c Ethernet Blade Switch for c-Class BladeSystems ...

GbE2c Ethernet Blade Switch for c-Class BladeSystems Compatibility with Cisco-based Networks white paper Abstract ..............................................................................................................................................2 Introduction .........................................................................................................................................2 Terminology.........................................................................................................................................3 Same technology, different form factor....................................................................................................3 VLANs and VLAN tagging.....................................................................................................................5 Spanning tree ......................................................................................................................................5 Trunking ..............................................................................................................................................6 Security...............................................................................................................................................7 Management .......................................................................................................................................7 Port mirroring.......................................................................................................................................8 Multicast traffic ....................................................................................................................................8 Network time .......................................................................................................................................8 Conclusion ..........................................................................................................................................9 For more information ............................................................................................................................9 Abstract This white paper describes the interoperability of the GbE2c Ethernet Blade Switch with Cisco-based Ethernet networks consisting of Catalyst switches. This document is not intended to be a guide for deploying a GbE2c Ethernet Blade Switch within a Cisco-based network. For this information, see the white paper, Deploying the GbE2c Ethernet Blade Switch into a Cisco-based Network. The intended audience for this paper includes engineers and system administrators familiar with the GbE2c Ethernet Blade Switch for HP BladeSystem c-Class. For readers not familiar with GbE2c Ethernet Blade Switch, please see the HP GbE2c Ethernet Blade Switch for c-Class BladeSystem - overview as well as the user documentation that shipped with the GbE2c Ethernet Blade Switch. To obtain these documents, go to the HP website (http://www.hp.com/support), and search for GbE2c. Introduction The c-Class BladeSystem consists of ProLiant BL server blades, the 10U (17 inch) c7000 server blade enclosure, network and power infrastructure components, and software that enables adaptive computing optimized for rapid deployment. The c-Class server blade enclosure holds the server blades and up to eight switch modules. Each server contains multiple network interface controllers (NICs). The enclosure has a signal backplane that routes the server blade NIC signals to the Blade switches in a redundant, highly available architecture. HP offers a family of interconnect options for a choice of how the Ethernet, as well as Fibre Channel, signals exit the server blade enclosure. Available interconnects include two Ethernet switches, two patch panel pass-through modules (Ethernet and FibreChannel), and a FibreChannel SAN switch. The two patch panel options allow all Ethernet network signals to pass through to third-party LAN devices, thus giving customers flexibility in choosing their own switches. The interconnect switches provide up to 32-to-1 Ethernet cable consolidation reducing the time to deploy and manage HP BladeSystem c-Class. The GbE2c Ethernet Blade Switch is available for HP’s BladeSystem c-Class. The GbE2c Ethernet Blade Switch is an industry-standard all Gigabit Ethernet switch with five uplink ports and 14 internal server ports, and is intended for: • Applications that require up to 1000 megabits per second (Mb/s) NIC consolidation • Connectivity to copper-based 10/100/1000T Ethernet networks • Advanced network feature support (including planned future options for layer 3 advanced routing protocols) In a typical application, the GbE2c Ethernet Blade Switch acts as a redundant access switch layer that is in turn connected to the core network often consisting of Catalyst switches from Cisco Systems (Cisco). This white paper identifies the interoperability of the GbE2c Ethernet Blade Switch for HP c-Class BladeSystems within a Cisco-based Catalyst switch Ethernet network. Topics discussed include VLANs, spanning tree, multi-link trunking, security, management, and more. Terminology Terminology used in this document that differs between Cisco Catalyst switches and the GbE2 Interconnect Switch is identified in Table 1. Table 1. Network terminology cross reference HP GbE2c Ethernet Blade Switch Cisco Catalyst switches VLAN tagging, 802.1Q tagging trunking, VLAN or 802.1q encapsulation port VLAN identification (PVID) VLAN identification (VLANID) link aggregation, multi-link trunking (MLT) EtherChannel, channeling spanning tree protocol group (STG) spanning tree instance IEEE 802.1s, multiple spanning tree per VLAN spanning tree (PVST), PVST+ port mirroring SPAN, RSPAN Same technology, different form factor In a typical tiered server network configuration designed with redundancy, two or more network interface controllers (NIC) are used per server. The Ethernet signals from these NICs are routed to two separate access switches that are in turn connected to the core network. One or more “crosslink” connections are commonly made between the access switches for added availability. The access switch “downlink” ports are used to collect NIC signals from the servers for aggregation to the network backbone via one or more “uplink” ports. The GbE2c Ethernet Blade Switch and c-Class blade architecture use the same technology to provide this function, but in a different form factor (Figure 1). Figure 1. Typical redundant network configuration The access switches and connections have been moved inside the c-Class server blade enclosure. The GbE2c Ethernet Blade Switches become the access switch layer, which is in turn connected to the core switch layer. The same network technology is used and the tiered network configuration remains unchanged. Because the GbE2c switch is an industry-standard managed layer 2 switch, it is compatible with other industry-standard switches including Catalyst switches from Cisco. The remainder of this paper discusses the GbE2c Ethernet Blade Switch interoperability with Cisco Catalyst switches in the areas of: • VLANs and VLAN tagging (VLAN trunking) • spanning tree • multi-link trunking (EtherChannel) • security • management • port mirroring (SPAN, RSPAN) • multicast traffic VLANs and VLAN tagging Each GbE2c Ethernet Blade Switch provides 255 port-based IEEE 802.1Q virtual local area networks (VLANs) compatible with Catalyst switches that support this industry standard. Both the Catalyst switches and GbE2c Ethernet Blade Switches utilize VLAN1 as the default VLAN, thus permitting immediate out-of-the-box passing of Ethernet traffic. To create VLANs across the network, the GbE2c Ethernet Blade Switch supports IEEE 802.3ac VLAN Ethernet frame extensions for 801.2Q tagging.1 Each switch port may be individually configured as tagged or untagged. Therefore, GbE2c Ethernet Blade Switch VLANs may span Cisco switches that support the 802.1Q tagging methodology. Although Cisco typically refers to 802.1Q VLAN tagging as VLAN trunking or dot1q trunking, the technologies are the same, and therefore, completely interoperable. The key is to ensure that ports on both ends of the tagged link (or dot1Q trunk) are assigned to the same VLANs. The Cisco proprietary VLAN tagging Inter Switch Link (ISL) is an alternative method that predates the IEEE 801.1Q tagging standard. The GbE2c Ethernet Blade Switch does not support ISL. Cisco recommends that “…new implementations follow the IEEE 802.1q standard and older networks gradually migrate from ISL” to allow multi-vendor interoperability, greater field exposure, greater 2 third party support, and, to a lesser degree, 802.1Q’s lower encapsulation overhead. Lastly, the GbE2c Ethernet Blade Switch cannot be used as a participating node with Cisco’s VLAN Trunk Protocol (VTP). However, the GbE2c switch may be used as a VTP transparent node to forward VTP information. Spanning tree Spanning tree is enabled by default on the GbE2c Ethernet Blade Switch to ensure that any existing network layer 2 loops are blocked. The GbE2c Ethernet Blade Switch meets the IEEE 802.1D standard and is compatible with Cisco switches that are 802.1D compliant. The bridge priorities, port costs, and port priorities may be manually assigned on the GbE2c Ethernet Blade Switch, allowing the core or other Catalyst switches to be the root bridge. The GbE2c Ethernet Blade Switch further provides interoperability with Cisco’s Per-VLAN Spanning Tree Plus (PVST+) 801.Q tagging proprietary protocol via the use of spanning tree groups (STG). In the GbE2c implementation, an administrator creates an STG and then assigns a VLAN to it. This differs from the Cisco implementation where an administrator creates a VLAN, and then a spanning tree instance (i.e. STG) is automatically created and assigned to the VLAN. The PVST+ interoperability feature on the GbE2c Ethernet Blade Switch includes the following: • Tagged ports may belong to more than one STG, but untagged ports can belong to only one STG. • When a tagged port belongs to more than one STG, egress BPDUs are tagged to identify their STG membership. • An untagged port cannot span multiple STGs. 1 The IEEE 802.3 standards have been merged into a single standard defined as IEEE 802.3-2002. IEEE 802.3-2002, section 3.5 (Elements of the Tagged MAC Frame) now contains the specifications previously defined in IEEE 802.3ac. 2 Best Practices for Catalyst 4000, 5000, and 6000 Series Switch Configuration and Management, Cisco Systems, Document 13414, October 1, 2003; available at http://www.cisco.com/en/US/products/hw/switches/ps663/products_tech_note09186a0080094713.shtml . • Each GbE2c Ethernet Blade Switch supports sixteen STGs operating simultaneously (STG 16 is reserved for switch management). • The default STG 1 can hold multiple VLANs; all other STGs (groups 2–16) can hold one VLAN. The GbE2c Ethernet Blade Switch provides two methods to interoperate with PVST+: 1. All GbE2c Ethernet Blade Switch VLANs configured on the ports connected to the Catalyst switches may be added to the default STG (STG 1). 2. A unique GbE2c Ethernet Blade Switch STG may be created for each of the configured VLANs connecting to the Catalyst switches. For rapid spanning tree convergence, many Catalyst switches support Cisco’s proprietary features PortFast, UplinkFast, and BackboneFast, as well as the industry-standard IEEE 802.1w. The 802.1w extension is an enhancement to the original 802.1D standard. As noted by Cisco, 802.1w provides similar convergence time improvements to the Cisco methods, but 802.1w provides the added benefit of interoperability between vendors. The GbE2c switch supports a single instance of 802.1w. Trunking Trunking, also know as link aggregation, port trunking, and Cisco EtherChannel, combines multiple physical switch ports into a single logical port called a trunk. The bandwidth of the trunk is the aggregate of the bandwidth of the individual links. The industry standard for trunking is IEEE 802.3ad.3 Cisco has developed a similar trunking method known as EtherChannel. The GbE2c Ethernet Blade Switch supports IEEE 802.3ad (802.3-2002) without LACP4 which is compatible with EtherChannel. The GbE2c switch interoperates with both Fast EtherChannel, providing link aggregation for Fast Ethernet (100MB) ports, and Gigabit EtherChannel, which aggregates Gigabit Ethernet (1000MB) links. The GbE2c Ethernet Blade Switch supports twelve trunks per switch. Each trunk may contain two to five ports providing a 10-Gbps aggregate throughput full duplex. An algorithm automatically applies load balancing to the ports in the trunk. A port failure within the trunk group causes the network traffic to be directed to the remaining ports. Load balancing is maintained whenever a link in a trunk is lost or returned to service. This provides flexible and scalable bandwidth with resiliency and load sharing across the links between the GbE2c Ethernet Blade Switch and Cisco devices. To determine the load balancing decisions, varying methods are used. Catalyst switches may use the packet’s source MAC (SMAC) address, destination MAC (DMAC) address, source IP (SIP) address, destination IP (DIP) address, or a combination of these methods. Similarly, the GbE2c Ethernet Blade Switch uses a combination of SIP and DIP addresses to make the load balancing decision; or information embedded within the data frame doesn’t contain IP traffic, the switch will load balance based on the packet’s SMAC and DMAC address. 3 The IEEE 802.3 standards have been merged into a single standard defined as IEEE 802.3-2002. IEEE 802.3-2002, section 43 (Link Aggregation) defines the standards specified in IEEE 802.3ad. 4 Link aggregation control protocol (LACP) is an enhancement over EtherChannel and other static multi-link trunking methods. LACP dynamically learns about the link status and takes decisions on which links to use for and load balancing and failback in case of link failure. As a result, IEE 802.3ad with LACP is often called dynamic trunking. Security The GbE2c Ethernet Blade Switch supports remote authentication dial-in user service (RADIUS) client, communicating to the network RADIUS server to authenticate and authorize a remote administrator using the protocol definitions specified in RFC 2138 and 2866. The GbE2c Ethernet Blade Switch will integrate into an existing Cisco network that uses this industry-standard authentication and authorization protocol. As is performed on the Catalyst switches, the RADIUS configuration on the GbE2c Ethernet Blade Switch requires the user to specify the IP address of the RADIUS server and the RADIUS secret. For enhanced security, the GbE2c Ethernet Blade Switch permits modification of the RADIUS application port, user-configurable RADIUS server retry and time-out values, and support for SecurID if the RADIUS server can perform an ACE/server client proxy. Both a primary and a secondary RADIUS server may be configured. • As an alternative to the industry-standard RADIUS protocol, GbE2c offers interoperability with Cisco’s proprietary Terminal Access Controller Access Control System Plus (TACACS+) method. TACACS+ offers the following advantages over RADIUS as the authentication device: • TACACS+ is TCP-based, so it facilitates connection-oriented traffic. • It supports full-packet encryption, as opposed to password-only in authentication requests. • It supports decoupled authentication, authorization, and accounting. With support for both RADIUS and TACACS+ security methods, GbE2c provides the flexibility to interoperate in Cisco networks that use either protocol. Management The operating system (OS) of the GbE2c Ethernet Blade Switch provides multiple industry-standard methods to easily configure and manage the GbE2c Ethernet Blade Switch. Similar to many Catalyst switches, the GbE2c Ethernet Blade Switch can store redundant OS images and configuration files in memory. The GbE2c Ethernet Blade Switch may be managed and configured via: 1. Command Line Interface (CLI) 2. Browser based interface (BBI) 3. Simple Network Management Protocol (SNMP) The GbE2c Ethernet Blade Switch CLI consists of a hierarchal menu/command-based hybrid interface that has a Linux/Unix type look and feel. The hybrid approach permits new users to see available parameters for each command, and walks them through command parameters one-by-one. It also allows advanced users to perform command stacking and abbreviations similar to Cisco devices. Supported industry-standard scripting simplifies switch configuration management and deployment. The web console or BBI can be utilized via Internet Explorer or Netscape Navigator over a TCP/IP network. Thus, access is possible throughout the Cisco-based network. Like the CLI, the BBI provides the ability to configure and view GbE2c Ethernet Blade Switch settings and information. The GbE2c Ethernet Blade Switch supports industry-standard SNMP management information bases (MIBs), HP enterprise switch MIBs, and environmental traps. The SNMP agents are preinstalled in the GbE2c switch firmware. Redundant community strings and SNMP trap manager hosts can be configured per switch. This capability allows the interconnect switch to be monitored remotely from an SNMP network management station such as HP Systems Insight Manager5 and HP OpenView.6 Additionally, any SNMP-based manager within CiscoWorks or other third party offering may also be used, provided it can read industry-standard MIBs and process industry-standard traps. The GbE2c Ethernet Blade Switch provides other familiar management capabilities consistent with Catalyst switches. These include a local console port with XModem support, access through Telnet and secure shell (SSH), and deployment, back-up, and restore capabilities using trivial file transfer protocol (TFTP) and secure copy protocol (SCP). Port mirroring The GbE2c Ethernet Blade Switch port mirroring feature provides the ability send a copy of any network traffic that enters or leaves the switch to a designated (monitor) port for examination by a network analyzer. Traffic ingressing the port, egressing the port, or both may be monitored. The GbE2c port mirroring provides similar functionality as the switched port analyzer (SPAN) feature on Catalyst switches. The GbE2c Ethernet Blade Switch also interoperates with the Cisco Remote SPAN (RSPAN) feature. By targeting mirrored GbE2c data to a port connected to a Catalyst switch utilizing RSPAN, the traffic can be captured for analysis on the designated Catalyst monitoring port. Multicast traffic Multicasting reduces network traffic and congestion. The GbE2c Ethernet Blade Switch can pass IP multicast traffic that is forwarded to it from Catalyst switches. The GbE2c switch supports active participation within internet group management protocol (IGMP) v1 and v2 multicasting, with the Catalyst switch configured as the Mrouter. Otherwise, provided the VLANs between the GbE2c Interconnect and Catalyst switches are correctly configured, the GbE2c Ethernet Blade Switch will automatically forward IP multicast traffic out all ports on the VLAN from which the multicast traffic was received. Network time The industry standard network time protocol (NTP) synchronizes timekeeping among a set of distributed network devices and time servers. This synchronization allows events to be correlated when system logs are created and other time-specific events occur. As with Catalyst switches, the GbE2c Ethernet Blade Switch supports NTP. On the GbE2c Ethernet Blade Switch, users can specify the NTP server IP address, update interval, and time zone, and then the Cisco and GbE2c switches are synchronized to the same network time. The GbE2c Ethernet Blade Switch includes a battery-backed real time clock that will maintain the time in the event the NTP server is unavailable. 5 Available at http://h18000.www1.hp.com/products/servers/management/hpsim/index.html. 6 Available at http://h20229.www2.hp.com/index.html Conclusion With the introduction of industry-standard blade servers, the number of Ethernet connections and cables within a rack can quickly become overwhelming. To consolidate theses cables, blade manufacturers introduced the concept of integrated Ethernet switches. For network administrators to successfully deploy these new blade switches within their existing networks, interoperability with existing devices and compliance to network industry standards is a must. Available as one of the more cost-savvy and feature rich networking device options for the HP BladeSystem c-Class, the GbE2c Ethernet Blade Switch is ideal for reducing Ethernet network cabling and the time required to deploy, manage, and service the c-Class. The GbE2c’s advanced feature support and compliance to IEEE and other Ethernet protocols permits interoperability with networks based on Cisco Catalyst switches and devices from other common vendors found in today’s datacenter. For more information For additional information, refer to the resources detailed below. Resource description Web address GbE2c Ethernet Blade Switch http://h18000.www1.hp.com/products/blades/ homepage components/ethernet/GbE2c/index.htmlGbE2c Ethernet Blade Switch http://h20000.www2.hp.com/bizsupport/TechSupport/ documentation DocumentIndex.jsp?contentType=SupportManual&lang=en&cc=us&docIndexId=179111&taskId=101&prodTypeId=329290 &prodSeriesId=1845925GbE2c Ethernet Blade Switch http://h18000.www1.hp.com/products/blades/ key benefits components/ethernet/GbE2c/benefits.html#4Network Adapter Teaming white paper http://h18000.www1.hp.com/products/servers/networking/ teaming.html © 2006 Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein. Catalyst, Cisco, Cisco Systems, and EtherChannel are registered trademarks of Cisco Systems, Inc. All other trademarks or registered trademarks mentioned in this document are the property of their respective owners. Document Outline

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