Allied Telesis AT-9924T/4SP-A-20 manual Igmp Snooping and Recovery Times, Health Message Priority

Page 31

IGMP Snooping and Recovery Times

IGMP Snooping and Recovery Times

Since Software Version 281-03, IGMP snooping includes query solicitation, a new feature that minimises loss of multicast data after a topology change.

When IGMP snooping is enabled on a VLAN, and EPSR changes the underlying link layer topology of that VLAN, this can interrupt multicast data flow for a significant length of time. Query solicitation prevents this by monitoring the VLAN for any topology changes. When it detects a change, it generates a special IGMP Leave message known as a Query Solicit, and floods the Query Solicit message to all ports. When the IGMP Querier receives the message, it responds by sending a General Query. This refreshes snooped group membership information in the network.

Query solicitation functions by default (without you enabling it) on the EPSR master node. By default, the master node always sends a Query Solicit message when the topology changes.

On other switches in the network, the query solicitation is disabled by default, but you can enable it by using the command:

set igmpsnooping vlan={vlan-name1..4094all} querysolicit={onyestrue}

If you enable query solicitation on an EPSR transit node, both that node and the master node send a Query Solicit message.

Once the Querier receives the Query Solicit message, it sends out a General Query and waits for responses, which update the snooping information throughout the network. If necessary, you can reduce the time this takes by tuning the IGMP timers, especially the queryresponseinterval parameter. For more information, see the “IGMP Timers and Counters” section of “How To Configure IGMP on Allied Telesyn Routers and Switches for Multicasting”. This How To Note is available in the Resource Center of the Documentation and Tools CDROM for Software Version 2.8.1, or from: www.alliedtelesyn.co.uk/en-gb/solutions/techdocs.asp?area=howto

Query solicitation also works with networks that use Spanning Tree (STP, RSTP, or MSTP).

Health Message Priority

EPSR uses Health messages to check that the ring is intact. If switches in the ring were to drop Health messages, this could make the ring unstable. Therefore, Health messages are sent to the highest priority queue (queue 7), which uses strict priority scheduling by default. This makes sure that the switches forward Health messages even if the network is congested.

We recommend that you leave queue 7 as the highest priority queue, leave it using strict priority scheduling, and only send essential control traffic to it.

In the unlikely event that this is impossible, you can increase the failover time so that the master node only changes the ring topology if several Health messages in a row fail to arrive. By default, the failover time is set to two seconds, which means that the master node decides that the ring is down if two Health messages in a row fail to arrive.

Page 31 AlliedWare™ OS How To Note: EPSR

Page 30 Page 32
Image 31
Page 30 Page 32
Contents What information will you find in this document? IntroductionWhich products and software versions does it apply to? Epsr Components How Epsr WorksEstablishing a Ring Fault in a link or a transit node Recovering from a FaultFault in the master node Transit Nodes with Both Ports Down Restoring Normal OperationMaster Node Transit Nodes with One Port DownConfiguring Epsr How To Configure EpsrConfigure other ports and protocols as required Iii. Remove the ring ports from the default VlanIv. Configure the Epsr domain Enable EpsrModifying the Control Vlan Example 1 a Basic Ring Configure the Master Node aAdd the data Vlan to the domain Configure the Transit Nodes B and CRemove the ring ports from the default Vlan Create the Epsr domainCreate epsr=test mode=transit controlvlan=vlan1000 Example 2 a Double Ring Configure the master node switch a for domainConfigure Epsr Configure the master node switch C for domainConfigure the data Vlan for domain Example 3 Epsr and Rstp Configure the master node switch a for the Epsr domainRemove the STP VLAN’s ports from the default Vlan Configure switch E for Epsr and Rstp Epsr Domain Example 4 Epsr with Nested VLANsConfigure the Epsr control Vlan Configure client switch H connected to transit node D Configure client switch E connected to the master nodeConfigure client switch F connected to transit node B Configure client switch G connected to transit node CExample 5 Epsr with management stacking Configure stacking on the second transit node host3 Configure stacking on the first transit node host2Configure Epsr on the stacked switches Configure the other VLANs on the stacked switchesExample 6 Epsr with an iMAP Configure the AT-TN7100 iMAP as Master NodeFollowing diagram shows the expected output Checking the Master Node ConfigurationChecking the Transit Node Configuration Configure the AT-TN7100 iMAP as a Transit NodeLINKS-UP Classifiers and Hardware FiltersPorts and Recovery Times Health Message Priority Igmp Snooping and Recovery TimesEpsr State and Settings Epsr Information Name Domain1 Snmp Traps Counters Master node sends Health messages DebuggingLink Down Between Master Node and Transit Node Master Node Node a Debug OutputPrimary port goes down Master node continues sending Health messagesMaster node transmits a Ring-Down-Flush-FDB message Hello timer expires again Hello timer expiresPrimary port comes back up Master node receives the Ring-Up-Flush-FDB message on port Master node returns the ring to a state of CompleteMaster node transmits and receives Health messages Transit node receives Health messages Transit Node Node B Debug OutputTransit node receives a Ring-Down-Flush-FDB message Port 1 on the transit node goes downTransit node receives a Health message Port 1 comes back upTransit node receives a Ring-Up-Flush-FDB message 252 Link Down Between Two Transit Nodes Link between the two transit nodes goes down Master node receives a second Link-Down message Master node receives a Health message 51 AlliedWare OS How To Note Epsr 375 53 AlliedWare OS How To Note Epsr Transit node sends a Link-Down message Transit node receives another Health message Link comes back upTransit node receives a Ring-Up-Flush-FDB message

AT-9924SP-30, AT-9924T-40, AT-8948, AT-9924T/4SP-A-20, X900-48FE-N specifications

Allied Telesis is a leading provider of networking solutions, renowned for its innovative technologies and high-performance networking equipment. Among its extensive product lineup, the X900-48FE-N, AT-9924T-40, AT-8948, AT-9924T/4SP-A-20, and AT-9924SP-30 stand out for their remarkable features and capabilities.

The X900-48FE-N is a robust layer 2/3 managed switch that features 48 Fast Ethernet ports. This model is particularly known for its energy efficiency and reliability, making it a suitable choice for enterprises with demanding networking needs. It supports a wide range of Layer 2 Ethernet switching technologies, including VLANs, Spanning Tree Protocol (STP), and Link Aggregation Control Protocol (LACP), which enhances network reliability and efficiency.

The AT-9924T-40 is a versatile switch designed for high-performance environments. It offers a rich set of features, including 24 Gigabit Ethernet ports and 4 SFP ports for fiber connectivity. This device is equipped with Advanced Layer 2 and Layer 3 features, including IPv4/IPv6 support, Quality of Service (QoS) capabilities, and robust security options. This switch is ideal for core and distribution deployments within enterprise networks, ensuring fast and reliable connectivity.

The AT-8948 is another important model in Allied Telesis' offerings. It features 48 10/100 Mbps Ethernet ports and 4 Gigabit uplink ports, providing a high density of connectivity options. The AT-8948 is also equipped with advanced management capabilities, including SNMP, RMON, and web-based management, allowing for easy configuration and monitoring of the network.

The AT-9924T/4SP-A-20 offers a combination of 24 Gigabit Ethernet ports and 4 SFP slots to extend network capabilities through fiber connections. It is particularly well-suited for environments requiring high bandwidth and flexible connectivity. Its compact design makes it an excellent choice for data centers and enterprise networks.

Lastly, the AT-9924SP-30 is characterized by its 24 Gigabit SFP ports, offering flexibility in terms of fiber connectivity. This switch supports advanced routing capabilities and is designed for high-availability environments. Its ability to handle diverse network traffic while maintaining optimal performance makes it a valuable asset for any modern enterprise.

In summary, these Allied Telesis models showcase advanced features, network reliability, and versatile management options, making them critical components for efficient and scalable networking solutions.
Top Page Image Contents