LAN Switching Foundation Technologies

QoS Parameters for a Single PortSwitch1 (enable) show port qos 10/3 Config: Port ACL name ... [full story]

Calculating MAC Address for Multicast Group Port 10/1 is configured to accept the 239.1.1.1 stream on VLAN 3. (See Example 9-2.) All other ports should not receive this traffic anymore because the CAM table has only one port associated with ... [full story]

Creating a Static CAM EntrySwitch1 (enable) set cam static 01-00-5e-01-01-01 10/1 3 Static multicast entry added to CAM table. Switch1 (enable) show mac 10/1 Port Rcv-Unicast ... [full story]

IGMP Snooping IGMP snooping prevents multicast flows from flooding to all ports on a VLAN by monitoring the Layer 3 IGMP packets. Multicast streams are sent to ports that explicitly request the flow. The switch via the IGMP snooping mechanism listens ... [full story]

IGMP Snooping Process Between Source and Receiver on the Same VLAN This scenario will go step by step through the IGMP snooping process (refer to Figure 9-4). The first objective is to know what the configuration looks like on the router, ... [full story]

IGMP Configuration on the Router and Switchmsfc_15#show ip pim interface vlan3 Address Interface Version/Mode ... [full story]

Supervisor Multicast InformationSwitch1 (enable) show multicast protocols status IGMP enabled IGMP fastleave disabled RGMP disabled GMRP disabled Example 9-5 shows the IGMP max query response set at 10 seconds. A router must receive a ... [full story]

IGMP Interface Informationmsfc_15#show ip igmp interface vlan 3 Vlan3 is up, line protocol is up Internet address is 10.1.3.10/24 IGMP is enabled on interface Current IGMP host version is 2 ... [full story]

Multicast Source OnlySwitch1 (enable) show igmp groupinfo 3 01-00-5e-01-01-01 MAC Address: 01-00-5e-01-01-01 Multicast Flag: TRUE ... [full story]

IGMP Snooping Process Between the Source and a Second Receiver on the Same VLAN Figure 9-5 illustrates what happens when a second host from the same VLAN sends a membership report to the router. Figure 9-5. Host3 Sends a Membership Report The ... [full story]

IGMP Snooping Process Between Source and Receiver on Different VLANs Host4 from a different VLAN has requested the multicast stream 239.1.1.1. (See Figure 9-6.) Figure 9-6. Host4 Sends a Membership Report A hardware shortcut is created by the MSFC in this scenario ... [full story]

Multicast Statistics on the SwitchSwitch1 (enable) show mls multicast statistics Router IP Router Name Router MAC --------------- ------------------ ----------------- ... [full story]

IGMP Leave Process This section explores two types of leave process. The first leave process involves a single host leaving a multicast session while other hosts from the same VLAN are still receiving the multicast traffic. In the second example, the ... [full story]

IGMP Snooping Leave Process Between the Source and Multiple Receivers on the Same VLAN Figure 9-7 and the subsequent steps outlined address the issue of a receiver leaving a multicast group while another receiver on the same VLAN is still interested ... [full story]

Multicast Traffic Is Sent Only to Host2 To manually configure ports to receive the multicast stream, it is important to know how to derive the Layer 2 MAC address for the multicast group 239.1.1.1. The first 4 bits of the ... [full story]

Multicast Flooding Because no specific host is associated with the multicast MAC address in the content-addressable memory (CAM) table, multicast traffic is flooded throughout the VLAN. (See Figure 9-1.) This type of setup creates unnecessary traffic on the VLAN and wastes ... [full story]

Input Scheduling Input scheduling is the next step involved in handling the frame after the frame has arrived at the ingress port, assuming the port has been configured for trust-cos (refer to Figure 8-1). Input scheduling basically assigns incoming frames to ... [full story]

Type of QoS SchedulingSwitch1 (enable) show port capabilities 10/3 Model WS-X6248-RJ-45 Port ... [full story]

Default Parameters for 1q4t rxSwitch1 (enable) show qos info config 1q4t rx QoS setting in NVRAM for 1q4t receive: QoS is enabled Queue and Threshold Mapping for 1q4t (rx): Queue Threshold CoS ----- --------- --------------- ... [full story]

Marking and Policing The next step after input scheduling is for the frame to be forwarded to the switching engine (PFC/PFC2). The switching engine will mark every frame with an internal DSCP value. This marking will help the switching engine to appropriately ... [full story]

CoS to DSCP MapSwitch1 (enable) show qos map runtime cos-dscp-map CoS - DSCP map: CoS DSCP --- ---- 0 0 1 8 ... [full story]

Marking The switching engine forwards the traffic to the egress port. The internal DSCP values assigned to the traffic at the switching engine are marked back to their respected CoS or DSCP/IP precedence values at the egress port. For example, the ... [full story]

Output Scheduling After marking, the traffic is forwarded to the appropriate transmit queue on the egress port (see Figure 8-5). Depending on the hardware module used, the number of queues and drop thresholds varies. The reason behind the queues on the ... [full story]

QoS Information for 2q2t txSwitch1 (enable) show qos information config 2q2t tx QoS setting in NVRAM for 2q2t transmit: QoS is enabled Queue and Threshold Mapping for 2q2t (tx): Queue Threshold CoS ----- --------- ... [full story]

QoS Information for 1p2q2t txSwitch1 (enable) show qos information config 1p2q2t tx QoS setting in NVRAM for 1p2q2t transmit: QoS is enabled Queue and Threshold Mapping for 1p2q2t (tx): Queue Threshold CoS ----- --------- --------------- ... [full story]

QoS Caveats Caveats regarding QoS and the Catalyst 6500 switch include the following: Etherchannel— Etherchannel ports require identical QoS configurations on the individual ports. IGMP snooping— QoS does not support IGMP traffic, if IGMP snooping is enabled on the switch. MSFC— Any traffic sourced ... [full story]

Implementing Multicast on Catalyst Switches This chapter covers the following topics: Understanding IGMPv1 and IGMPv2 Multicast flooding IGMP snooping CGMP IGMP snooping versus CGMP Multicast deployments have increased exponentially over the past 4 years. A single host sources traffic to a multicast group, which has multiple members ... [full story]

Understanding IGMPv1 and IGMPv2 Communication between the router and the host is done via the IGMP, which has two versions. In IGMPv1, two IGMP packets are defined. The first packet is a membership query sent by the query router every 1 ... [full story]

IGMP Sniffer Trace IP: Protocol = 2 (IGMP) IP: Header checksum ... [full story]

IGMP Snooping Leave Process Between the Source and Last Receivers Figure 9-8 illustrates the last receiver, Host4, on VLAN 30 leaving the multicast group 239.1.1.1. When Host4 leaves the multicast group, both switch and MSFC will have to update their appropriate ... [full story]

IGMP Fastleave With IGMP fastleave enabled, the switch removes the port from the multicast forwarding table without sending a MAC-based query to the port. The purpose behind fastleave is to quickly transition the port or VLAN off the multicast stream. Most ... [full story]

Spanning Tree Information for VLAN 3Switch2 (enable) show spantree 3 VLAN 3 Spanning tree mode PVST+ Spanning tree type ... [full story]