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OS7000 Network Design and Configuration Guide. February 20, 2003. Version 4.0 Posted on the Intranet Website. From the IND home page: (aww.ind.alcatel.com) Select NIBU marketing Scroll down to sales and SE tools Click on “SE Corner” And “Voila!” The direct link is:
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OS7000 Network Design and Configuration Guide February 20, 2003
Version 4.0 Posted on the Intranet Website • From the IND home page: (aww.ind.alcatel.com) • Select NIBU marketing • Scroll down to sales and SE tools • Click on “SE Corner” • And “Voila!” • The direct link is: http://aww.ind.alcatel.com/nibu/se_corner.cfm • Versions 3.0 and 2.0 are also there for comparison
What is This Document? • Reference document • Table of contents and reference links “hot” hyperlinks • Not designed to replace the user manual • Does not replace the release notes • Explains the current status of each feature • Limitations explained • Some detailed background • Workarounds presented when possible • Sample configurations • Table of contents has hot links to sub-chapters • Not intended to be read cover to cover • (Unless you need a solution for insomnia)
What Does it Include? • Network design theory • Physical audit (Power, AC, cable types, traffic distribution) • Protocols (IP Addressing, VLAN architecture, AVLANs) • Capacity planning (Bandwidth requirements, future growth) • Management requirements (Logical & physical, secure access) • Security and Policies (Source control, physical and logical access) • Application prioritization (QoS) • Optimal network designs • Hierarchal (Edge, distribution, core) • Redundancy Methods (Link Agg., STP, RIP, OSPF, SLB) • Broadcast considerations • Scalability & Security
Features Covered • Redundancy / high availability • CMM Redundancy • Virtual Router Redundancy Protocol (VRRP) • Server Load Balancing (SLB) • 802.3ad Dynamic Link Aggregation (LACP) • OmniChannel • Switching / Layer 2 • Multicast Switching • 802.1w Rapid Reconfiguration Protocol • 802.1D Spanning Tree Protocol (STP) • 802.1Q • Group Mobility
Features Covered • Routing / Layer 3 • Open Shortest Path First (OSPF) • Routing Information Protocol (RIP) • Border Gateway Protocol (BGP) • Distance Vector Multicast Routing Protocol (DVMRP) • Protocol Independent Multicast Sparse Mode (PIM-SM) • UDP Relay • QoS (Quality of Service) • QoS Generalities • Differentiated Services Code Point (DSCP) • Type of Service (ToS) • 802.1p
Features Covered • Security • Authenticated VLANS • Access Control Lists (ACLs) • Network Address Translation (NAT) • OS6600 specific functionality • Introduction • IP Switching • IP Telephony Primer • Bandwidth requirements for various codecs • Voice quality (delay, jitter, throughput, packet loss) • VoIP audit • QoS: What type and where • Deploying VoIP in a converged network
Features Covered • System limitations • OS6600 • Stacking limited to 4 in first release • Group mobility: One VLAN per protocol per port • Link aggregation limited to one ASIC • Multicast routing, port mirroring • L3/L4 Classification requires IP Switching • System limitations • OS7000 • Link Aggregation • Port Mirroring • IP Multicast Routing • BGP Scalability
Link Aggregation Issue • Broadcast traffic is forwarded in software • In some configurations the following can happen: • Broadcast traffic can be looped back and duplicated • Unwanted MAC address movement • Software fix for problem in 5.1.3. R01 • Release date first week in January • Retrofit into 5.1.1 R03 due out end of January • Ultimate fix is Coronado II • Current availability date is Q2 2003
Network Mac2 PortA Switch ‘F’ Switch ‘S’ LnkAgg Mac3 Mac1 PortB How Does it Happen? • Packet sent from Mac 2 to Mac 1 • Mac 1 is unknown in switch “S” • Flooded to switch “F” over the aggregate • Switch “F” has previously learned Mac 1 on the aggregate
How Does it Happen? Network • Load sharing algorithm can choose port A or B • If egress port == ingress port, Coronado drops the packet • If not, packet arrives in switch “S” and is a duplicate • Switch “S” now learns Mac 2 as source Mac on aggregate Mac2 PortA Switch ‘F’ Switch ‘S’ LnkAgg Mac3 Mac1 PortB
Software Workaround • What was done in software? • Change made for Gigabit NIs only (10/100 still has problem) • Source learning was modified to detect when: • A Mac DA has a source port that is the same as the aggregate • In this case the destination queue ID is set to the drop queue. • Prevents frame duplication and unwanted Mac movement • Modifications are straightforward and hardware handles issue • No effect on the rest of the source learning logic • No configuration required - change is unconditional • All ports on the Coronado are part of the SAME aggregate • Any packet from a basic port to the aggregate will be dropped • QoS Rules for these Mac addresses cannot be used • The rules might modify the queue ID (not the drop queue)
Configuration Work-Around • The problem described only occurs on bridged links • Configure the links as routed connections (separate subnets) • Must use command: “qos classifyl3 bridged enable” • Routed connections use MAC addresses of routers • Since MAC addresses are the same on both ends • Load sharing is not effective • Command causes load sharing to use IP instead of MAC addr. • Problem solved! • Other ports of Coronado not forced to be part of aggregate
Port Mirroring • Coronado hardware can’t port mirror at wire speed • Egress wire speed, ingress software • Software modification: one port at a time to be monitored • Could handle two, but limited to one by configuration • Less than wire speed performance • Cumbersome to use • Problem corrected by Coronado II • Current schedule is Q2 2003 • With fix, four ports can be monitored at wire speed • Mixed configurations with Coronado I and Coronado II limited
IP Multicast Routing - (Chapter 7.4 in Document) • Layer 2 traffic is ALWAYS sent at wire speed • Some routed multicast traffic sent via software • Performance: 32,000 - 37,000 packets per second • Conditions that require hardware routing to be turned off • Presence of 802.1Q trunks where traffic is routed • Fragmentation between ports with different MTU sizes • UDP packets with non-standard size headers (>20 bytes) • PIM encapsulated packets • Packets requiring translation (SNAP to Ethernet II) • Unicast tunnels transporting multicast traffic • IP multicast hardware-routing • IP multicast no hardware-routing
IP Multicast Routing - (Chapter 7.4 in Document) • Software changes in AoS 5.1.3 R01 • Automatic detection of 802.1Q trunks • No longer necessary to turn off hardware routing manually • Other non-tagged connections remain wire speed • Unicast tunnels and PIM packets also detected automatically • Must turn off hardware routing for remaining conditions: • Fragmentation between ports with different MTU sizes • UDP packets with non-standard size headers (>20 bytes) • Packets requiring translation (SNAP to Ethernet II) • Other Fixes for multicast issues found a the TIC • Duplicate multicast streams routed by DVMRP routers • DVMRP not creating forwarding entries when metric modified
802.1Q Workaround - Add a Non-Tagged Trunk Disable MC routing on VLANs 1-4. Enable on VLAN 5. Traffic routed at wire speed! Video Server VLAN 7 Video Server Untagged Trunk (VLAN 5) VLAN 6 Main Switch MC Switching (No Routing) 1 2 End Users 3 4 802.1Q Tagged Trunk
802.1Q Workaround - One-Armed Router One-Armed Video Server MC Router VLAN 1 VLAN 1 2 3 Untagged Links Provides Wire Speed Multicast Routing 4 Main Switch MC Switching (No Routing) 1 2 End Users 3 4 802.1Q Tagged Trunk
802.1Q Workaround - Multiple Video Servers Video Server Video Server VLAN 1 VLAN 2 Video Server Layer 2 traffic is switched at wire speed! VLAN 3 Main Switch Video Server MC Switching VLAN 4 (No Routing) 1 2 3 End Users 4 802.1Q Tagged Trunk
Multicast on OS6600 • Currently multicast routing not supported on OS6600 • Hardware limitations of Intel IXE2424 • When scr/dest flow is learned, additional flows don’t go to software • DVMRP can’t function correctly because it can’t prune • Engineering decided a partial DVMRP to be unwise • It is possible to deploy multicast with some restrictions: • Only one active interface at a time (configure precedence) with routers that could be looped • Router will dynamically select interface to provide redundancy • Cascaded leaf routers are OK
Multicast on OS6600: An Example Switch2 Switch 1 VLAN 2 Video Server OS7000 DVMRP OS7000 DVMRP Configure VLAN 3 as preferred link (closer to video source) VLAN 3 VLAN 1 OS6600 DVMRP End Users End Users End Users OS6600 DVMRP End Users
Multicast on OS6600: Why is this Important? • Without L3 multicast support, OS6600 needs to Q-tag to core • OS7000 routing is not wire speed on Q-tagged trunks • Once you tag to the core, why unicast route on the edge? • The OS6600 slowly becomes an L2 switch • It erodes the “advanced switch” story • Limitations are not unreasonable • If you need full DVMRP, use OS7000 • If the OS6600 did everything the OS7000 does, we wouldn’t sell OS7000! • Leverage OS6600 wire-speed delivery over Q-tagged trunks • Cascade 6124/6148 off of OS6600
Patent Pending Method for MC Traffic Over Q Trunks • Utah team defined MC optimization method for Q trunks • Send one copy on one VLAN, duplication done downstream • Q-tag Multicast Optimization for Proactive Switching (QMOPS) • (That’s a joke! There is no formal name) • Only one “join” message sent upstream • Subsequent join requests managed by downstream switch • All packet duplication done in downstream switch • Traffic is not copied on Q trunks from OS7000 • Present to customers as optimization • Bandwidth is conserved: one packet across trunk, not multiple • Requested option to specify “primary” VLAN
MC Traffic Optimization Over Q Tagged Trunks Video Server Video Server VLAN 1 VLAN 5 VLAN 1 MC Client VLAN 3 Main Switch MC Client MC Routing 1 2 VLAN 4 3 IPMS Only MC Client End Users 4 (No Router) 802.1Q Tagged Trunk
IP Multicast Routing Information Resources • Chapter 7.4 in the document • Routing solutions Web page has great stuff! • FAQ pages, support info, white papers, presentations • IND home page > routing solutions (under Product information) • Web Address: http://aww.ind.alcatel.com/products/routing.cfm • Jeff Thomas is happy to answer any other questions • His e-mail address is: jeff.thomas@ind.alcatel.com
That’s All Folks!!!!!!!!!!!!!!!!!!!!! • For those of you asleep at the Beginning: • From the IND Home Page: (aww.ind.alcatel.com) • Select NIBU marketing • Scroll down to sales and SE tools • Click on “SE Corner” • And “Voila!” • The Direct link is: http://aww.ind.alcatel.com/nibu/se_corner.cfm • Versions 3.0 and 2.0 are there for comparison • Questions Welcome!