PowerPoint PresentationAlcatel-Lucent University Antwerp
University
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Entry level requirements:
You must have a basic theoretical knowledge of STP and RSTP.
You must be able to configure the basic configuration for the 7302 ISAM both via AWS and full CLI.
STP/RSTP/MSTP
Overall, the spanning tree protocol provides two main benefits. First, it has the ability to eliminate potential looping problems that could cripple a network, and finally it allows redundant links to be kept in reserve and automatically activated when they are needed and deactivated when they are not.
What is Link Aggregation?
Link aggregation allows one or more links to be aggregated together to form a Link Aggregation Group, such that a MAC Client can treat the Link Aggregation Group as if it were a single link.
Link aggregation also offers some resilience: if one of the links in a link aggregation group fails, the traffic will be handled by the remaining links (with a lower total capacity).
What is NT redundancy?
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Describe the most important xSTP parameters
Enable/disable xSTP on the system
Configure xSTP settings on a network port
Check the status of the network ports in a spanning tree
Describe link aggregation
Configure a LAG
Describe and compare the different scenario’s for access resiliency (NT redundancy)
Configure NT protection.
Alcatel-Lucent University Antwerp
Spanning Tree Protocol
In this section the ISAM implementation of (Rapid) Spanning Tree Protocol is described. The theoretical background is described in the document 3FL00275 part B.
Algorhyme (Radia Perlman)
A tree whose crucial property
Is loop-free connectivity.
So packets can reach every LAN.
First the Root must be selected
By ID it is elected.
Least cost paths from Root are traced
In the tree these paths are placed.
A mesh is made by folks like me
Then bridges find a spanning tree.“
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Avoids loops in a bridged network
provides path redundancy
RSTP backwards compatible with STP
RSTP limits number of hops (typically 8)
xDSL
xDSL
X
X
X
Spanning Tree Protocol (802.1d) and its variant RSTP have been developed in order to avoid that loops are created which could result in broadcast storms.
Spanning-Tree Protocol (STP) prevents loops from being formed when switches or bridges are interconnected via multiple paths. Spanning-Tree Protocol implements the 802.1D IEEE algorithm by exchanging BPDU messages with other switches to detect loops, and then removes the loop by shutting down selected bridge interfaces. This algorithm guarantees that there is one and only one active path between two network devices.
Recovery time of STP ~ 50 seconds ( recovery time for RSTP: 100 ms!). STP was designed at a time where recovering connectivity after outage within a minute or so was considered adequate performance
upon reconfiguration, bridge ports must wait for new topology information to propagate through the domain before transitioning from ‘blocking’ to ‘forwarding’ state (30-60 second expiry timer) hence limitation of 7 hops …
RSTP versus STP:
The main difference between STP and RSTP is in the negotiation between nodes on the network - everything else is identical. In RSTP, the BPDU format has changed due to the consolidation of several aspects of STP to streamline performance. For instance, in STP there are five different states that a port can be in, while in RSTP there are only three. Second, there are several points during the negotiation of BPDUs that have been made more efficient. As an example, when sending or receiving BPDUs, the STP system waits for a specific amount of time before acting. In RSTP these delays are reduced or eliminated. Finally, RSTP can detect and reconfigure the logical topology of a network much quicker than STP because of more efficient communication between the nodes. All of these benefits of RSTP result in faster reconfiguration of the network, making 802.1w a better candidate for eliminating loops in modern Ethernet networks.
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Avoids loops in a bridged network
MSTP is VLAN-aware
Uses RSTP for rapid convergence
Instance 1
(VLAN30, VLAN40)
Instance 2
Instance 2
Instance 1
MSTP is the 802.1s IEEE standard.The idea is that several VLANs can be grouped into a spanning tree “instance”, with each instance having a spanning-tree topology independent of other spanning-tree instances.
This architecture provides multiple forwarding paths for data traffic, enables load balancing and reduced the number of spanning-tree instances required to support a large number of VLANs.
A common Region Name,Format Selector, and Revision Level logically group switches into a Region. This allows for greater scalability, since each region now defines the logical boundary of the spanning tree network.
Therefore, each spanning tree instance converges separately and has its own root bridge.
This allows for seamless interoperability between areas of the network that do not support multiple spanning tree processes with others that do.
 Every bridge/switch has a single MST configuration with following attributes:
Alpha numeric configuration name
A config revision nr
Mapping table VLAN – instance
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Configure mstp general version
rstp : rapid spanning tree protocol IEEE 802.1w
mstp : multiple spanning tree protocol IEEE 802.1srstp
Additional parameters :
[no] priority : stp bridge priority(n*4096)
[no] max-age : stp max-age for root-bridge(n*100)
[no] hello-time : stp hello-time for bridge acting as root(n*100)
[no] forward-delay : forward delay value (n*100)
[no] tx-hold-count : maximum transmission rate limit
[no] path-cost-type : version of stp default path cost
[no] max-hop-count : max hop count(n*100)
Default bridge priority is 32768. Other values can be selected from the list (all multiples of 4096 from 0 to 61440).
Bridge hello time in seconds. Default: 2 s. Granularity: 1 s. Range: 1..10s.
With RSTP 802.1w, BPDUs with the current information are sent every hello-time, and not simply relayed anymore. With 802.1d, a non-root bridge would only generate BPDUs when it received one on its root port.
Root bridge forwarding delay in seconds. Default: 15s. Granularity: 1s. Range: 4..30.
The forwarding delay is the max. time needed to recalculate a spanning tree (=recovery time), i.o.w. the time a port stays in a certain state before moving to the next state.
Bridge max. age. Default = 20s. Granularity: 1 s. Range: 6-40.
On a given port, if hellos are not received for three consecutive times, protocol information can be immediately aged out (or if max_age expires). A bridge considers that it has lost connectivity to its direct neighbor if it misses three BPDUs in a row. This fast aging of the information allows quick failure detection. If a bridge fails to receive BPDUs from a neighbor, it is certain that the connection to that neighbor has been lost, as opposed to 802.1d where the problem could have been anywhere on the path to the root.
Max. age = max. age of info learned from the network on any port before it is discarded.
Tx. hold count: max. number of BPDUs to be transmitted before transmissions are subject to a one-second timer. Default:3. Range: 1..10.
Difference between IEEE802.1d and 802.1t:
IEEE802.1d calculates the port cost using the short method (16 bit).
The IEEE 802.1D specification assigns 16-bit (short) default port cost values to each port that is based on bandwidth. You can also manually assign port costs (in theory between 1–65535; on the ISAM n*4096 from 0 to 61440). The 16-bit values are only used for ports that have not been specifically configured for port cost.
IEEE802.1t calculates the port cost using the long method (32 bit).
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Configure mstp port 3
[no] disable-stp : current Msti port state disabled
path-cost : port path cost
[no] admin-p2p : admin p2p status of the LAN segment
attached to the port
[no] hello-time : port hello time
RSTP (or STP) is only supported on network ports, not on subtending ports or user ports! However, RSTP is supported towards DSLAMs in a ring topology.
The port priority is a multiple of 16 (i*16, where i ranges from 0 to 15) that you can select from a list. Default value = 128.
For link type, you can select:
Point-to-point (there’s only one host on this segment)
Shared (there are several hosts on this segment)
Auto
Edge port = a port at the edge of the bridged network. No loops are expected at the edges, so STP will not act on this port. Make sure there can be no loop!!
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Configure RSTP settings applicable to the SHUB :
configure mstp general version rstp
configure mstp general ….
configure mstp port (port)
RSTP operates on a port rather than on a VLAN
The NE can be configured with several network interfaces. They can be used to connect the NE to multiple Ethernet switches. The Rapid Spanning Tree Protocol (RSTP) is a link management protocol that provides path redundancy while preventing undesirable loops in the network. This procedure provides the steps to configure RSTP management on the NE.
Specify RSTP settings applicable to the SHub (I.e. the bridge as a whole!):
configure mstp general
path-cost-type <Shub::RstpPathCost>.
Specify RSTP settings applicable to a particular port of the Shub:
configure mstp port (port)
(no) hello-time
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General configuration :
stp-compatible : spanning tree protocol IEEE 802.1D
rstp : rapid spanning tree protocol IEEE 802.1w
Mstp : multiple spanning tree protocol IEEE 802.1s
Configure mstp general region-name <NAME>
Configure mstp general no disable-stp
Create instance with VLAN(s) association :
Configure mstp instance 1 priority n ( n=N*4096)
Configure mstp instance 1 associate-vlan 100
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MSTP configuration on SHUB port(s) :
Configure mstp port 0 no disable-stp admin-p2p force-true priority 48
[no] admin-p2p admin status of the LAN segment attached to the port
Possible values: - force-true : p2p link connection
- force-false : shared media connection
- optional parameter with default value: 128:
- range: [0...240]
By default, RSTP is enabled on out-band management link
Neither visible, nor configurable with AWS!
Configure with CLI (make sure there’s no loop!!):
Disable RSTP/MSTP:
configure the out-band management port as edge port
configure mstp port (port) edge-port
By default, RSTP is enabled on an out-band management link. This implies that RSTP might decide to block the management port to avoid loops.
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Configuration
MSTP
MSTP = multiple spanning tree protocol
This protocol allows you to have several spanning trees for different sets of vlans.
CLI configure mstp general no disable-mstp …
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Configuration
MSTP
EML-USM
Spanning tree create spanning tree instance for a set of vlans.
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Configuration
MSTP
Navigate to a network port on the service hub.
assign a spanning tree instance (I.e. a set of vlans to be used in a spanning tree) to the network port
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What is Link Aggregation?
Link aggregation allows one or more links to be aggregated together to form a Link Aggregation Group, such that a MAC Client can treat the Link Aggregation Group as if it were a single link.
one or more links with the same speed can be aggregated to a LAG
Increased bandwidth
Increased availability (if a physical link fails, the LAG needn’t fail)
Load-sharing
Low risk of duplication or mis-ordering
What is a Link Aggregation Group?
A group of links that appear to a MAC client as if they were a single link. All links in a Link Aggregation Group connect between the same pair of aggregation systems. One or more conversations may be associated with each link that is part of a Link Aggregation Group.
a LAG appears to be a single link.
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Links can be aggregated into a link aggregation group (LAG)
only for network & subtending links
combine links with same speed
n x data rate of components links
aggregate participates in forwarding decision process
max. 7 (8) LAG
support for LACP
LAG
LAG
For all these topologies – the links between the nodes could be GE/FE or multiple FE/GE. Multiple network or subtending links can be used to connect the ISAM to the same peer by aggregating these links (component links) into a Link Aggregation Group using 802.3ad.
Link Aggregation Control Protocol – means that messages are exchanged between the switches through which it is also possible to detect a failure of a component link and on the basis of that failure swap all traffic to an active link.
IP-address can also be used for computing of hashing value when ISAM can behave as a router
There’s no limit to the number of link aggregation groups. Load balancing between different links within the Link Aggregation Group is supported. Note that Link Aggregation is not supported on user links.
Using link aggregation on the uplink interfaces provides the following advantages:
Higher link capacity: e.g. 200 Mbps instead of 100 Mbps when 2 FE links are aggregated.
Link redundancy: if one link fails, the other link takes over. Throughput is decreased, but the connection is not lost.
The following link aggregation combinations can be used in the 7302 ISAM:
• Network and Subtending links:
For a GE or FE type link, an aggregation can exist of maximum 7 component links (max. 8 in case ECNT-C is used).
• User links:
Link aggregation cannot be used for user links.
Hashing assures that all frames of a single (TCP) flow are sent over the same component – so no re-ordering needed
Based on MAC SA and/or DA
Based on IP SA and or DA
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Links can be aggregated into a LAG
only for network & subtending links
Enable/disable LACP:
Configure la >[no] disable-lacp (CLI)
Configuration
LACP = Link Aggregation Control Protocol
You can configure the system-level parameters associated to the link aggregation module of a Service Hub. You can start and stop the link aggregation module, and enable and disable the protocol for one or more Service Hubs.
Link Aggregation Control involves:
Checking that candidate links can actually be aggregated.
Controlling the addition of a link to a Link Aggregation Group, and the creation of the group if necessary.
Monitoring the status of aggregated links to ensure that the aggregation is still valid.
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Port
Configure
Select one or more ports in a LAG
Select the LAG
EML-USM
Before you can create link aggregation groups you have to be make sure that link aggregation is allowed (system settings: Link aggregation is started (protocol enabled))>
The command <Port > Link Aggregation > Aggregate> is available in the Service Hub when one configured network port is selected and one or more unconfigured ports. You can’t create a link aggregation group when you select only unconfigured ports or only configured ports!
After a LAG has been created, you can select the LAG that appears at the bottom of the list (on top of the contributing links). When you select this LAG, you can check the configuration (show config) and even change the link aggregation parameters (configure).
When you select a contributing link of a link aggregation group, you can deaggregate this link from the LAG.
Link Aggregation Parameters:
Actor Admin Key (4 hexadecimal characters 0 to 9A to Fa to f): Current administrative value for the aggregator. Default value = port id of the aggregator (=the configured port in your selection)
LACP Mode: Enable (default) / Manual: Used to enable LACP or manually aggregate the port
LACP Activity: Active / Passive
LACP Time-out: Short / Long
Active LACP: preference to speak
Periodic transmission of LACPDUs
Local actor switch
LACPDU = Link Aggregation Control Protocol Data Unit
LACPDUs are basic 802.3 Ethernet frames (untagged).
The LACP protocol depends upon the transmission of information and state, rather than the transmission of commands. LACPDUs sent by the first party (the Actor) convey to the second party (the Actor’s protocol partner) what the Actor knows, both about its own state and that of the Partner.
The information conveyed in the protocol is sufficient to allow the Partner to determine what action to take next.
Active or passive participation in LACP is controlled by LACP_Activity, an administrative control associated with each port, that can take the value Active LACP or Passive LACP. Passive LACP indicates the port’s preference for not transmitting LACPDUs unless its Partner’s control value is Active LACP (i.e., a preference not to speak unless spoken to). Active LACP indicates the port’s preference to participate in the protocol regardless of the Partner’s control value (i.e., a preference to speak regardless).
Periodic transmission of LACPDUs occurs if the LACP_Activity control of either the Actor or the Partner is Active LACP. These periodic transmissions will occur at either a slow or fast transmission rate depending upon the expressed LACP_Timeout preference (Long Timeout or Short Timeout) of the Partner System.
In addition to periodic LACPDU transmissions, the protocol transmits LACPDUs when there is a Need To Transmit (NTT) something to the Partner; i.e., when the Actor’s state changes or when it is apparent from the Partner’s LACPDUs that the Partner does not know the Actor’s current state.
LACP mode: enable lacp / disable lacp / manual
When you enable LACP and the actor key at the remote (partner) switch does not match, the link will never come up. You can overrule this by aggregating the links manually: the links will come up and LACP will be used. Disabling LACP completely wouldn’t be wise!
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[no] link-up-down-trap
Show la aggregate-list
Show la network-port-info
information of a member of a LAG
A Link Aggregation Group is identified by means of the primary link (= aggregator-port). The primary link for a LAG is the link with the lowest port number within the group, provided the operational state of the link is UP. The configuration should be performed for the primary link. The settings configured for the primary link of the Aggregation Group apply to each and every link that is a member of the Link Aggregation Group.
The primary link (= aggregator-port) may change during the lifetime of the aggregation group. To cope with this phenomenon, the operator is advised to repeat the configurations described in this procedure for each link of the Aggregation Group. Care must be taken to configure identical settings for all links within the Aggregation Group.
1 Specify the LAG parameters with the following command. (Remark: you can only configure an aggregator port via CLI if the network port is already configured!):
configure la aggregator-port (network-port)
(no) actor-sys-prio (actor system priority; range:0..255; default value=1)
selection-policy <….> (MAC SA and/or DA; IP SA and/or DA)
actor-key (range 0..65535)
(no) actor-port-prio (port priority for the actor; range: 0..255; default value=1)
(no) active-lacp (default: passive lacp) -- ‘active’ means the link is able to exchange LACPDU messages
(no) short-timeout (default: long timeout)
(no) aggregatable (port is candidate to be aggregated – default: no aggregatable)
lacp-mode (enable-lacp, disable-lacp, manual)
2 To enable (only needed after manual shut down) or disable the Link Aggregation feature.:
configure la no disable (to enable) ; configure la disable (to disable)
3 View information for a Link Aggregation Group configured on the Service Hub:
show la aggregator-info (port) (network port, MAC-address, aggregate (y/n), actor key, partner sys-id, priority, partner key)
4 View information for a member of a LAG configured on the Service Hub:
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VLAN is automatically associated to other links in the LAG
Connection
Configure
Show
EML-USM
VLANs are associated to the aggregator port (it’s not possible to associate a VLAN to the group as such). When you associate a VLAN to the aggregator port, the other ports inherit this association.
Alcatel-Lucent University Antwerp
NT Redundancy
In this section the different scenario’s for NT redundancy are explained and compared with each other. Both equipment protection switching and link protection switching play a role in access resiliency.
NT redundancy is the availability of an NT port to carry additional traffic in the event of problems with one or more NT ports or links or the installation of a redundant NT unit so that the second NT unit can carry traffic in case of problems with the first NT unit.
The NE supports NT redundancy in the form of link and equipment redundancy on the external links when two NT units are installed.
For link redundancy, you can configure the NE to protect the physical links.
For equipment redundancy, you can configure the NE to reduce the time required to repair malfunctioning parts of the NE.
In cases where both link and equipment protection are needed, you can use the LPS/EPS combined configuration option. This solution involves a full switchover of the links and equipment to the network.
In cases where links and equipment are uncoupled, an NT I/O is used.
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Redundancy Configurations
Link aggregation
Resiliency = ability to recover from failure (HW/SW/data)
port – LT – NT – link – NT – link – access/ - link – access/ - link - head-end
control
control
Protection required
The term may be applied to hardware, software or data.
Resiliency always matters when many users are impacted upon failure, so it was always crucial in aggregation and edge networks:
non-stop forwarding / graceful restart / MPLS…
Historically it was less important in access networks, but that changes now: especially when triple plays takes off, resiliency is crucial in access networks too!
“A chain is as weak as its weakest link”
Network resiliency relies on solid base of node protection + link protection
Link protection
Node protection
Node protection
Node protection
Node protection
Link protection
Link protection
Link protection
Link protection
Path protection
Equipment Protection Switching
1
16
(e.g. RSTP)
NT I/O
Equipment protection switching protects the system against hardware failures: e.g. if NT-A fails, there’s a switchover to NT-B. For the NT I/O there’s no redundant equipment (there’s less need for a redundant board, since it contains basically passive components with little chance of failures).
APS = Automatic protection switching
The NE supports line protection and EPS. If a second – redundant – NT unit is installed, EPS provides protection against internal failures of the active NT.
Remark:
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server cards (e.g. IVPS)
1+1 LT redundancy
LTs
traffic is only forwarded to the active NT
no equipment redundancy for xDSL boards (no N+1 LT redundancy)
only equipment redundancy for server boards (1+1 redundancy)
e.g. for IVPS (ISAM-voice)
NT I/O:
On the NT I/O four GE interfaces are available. These interfaces forward traffic to the active NT. Redundant links are present, so the NT I/O is connected both to NT-A as to NT-B.
The NT I/O makes it possible to uncouple link protection from equipment protection: a failing link will not cause a switchover to the redundant NT!
Until now, there’s no protection of dynamic data yet (e.g. routing information). It will take some time to build this database again after a switchover.
In the future also dynamic data protection! (ARP, IGMP…)
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NT-only protection through the NT I/O:
NT protection is available for two NT units with a single uplink connected through an NT I/O to the active NT. In case of failure of the active NT, the NT I/O automatically reconnects the single uplink to the appropriate switch fabric port of the standby NT.
NT-only protection through a passive fiber splitter (7302 ISAM only and only for optical interfaces!):
NT protection is available for two NT units with a single uplink connected through a passive splitter. The passive optical splitter interconnects the single fiber with an optical interface directly on the NT units (but is logically connected to the active NT unit). The NT protection switching is executed by a laser disable logic that is activated on the standby NT. The laser disable logic prevents the standby NT from disturbing uplink transmission from the active NT unit on the shared fiber.
When there‘s no NT I/O, a link failure may force an NT switchover in case of combined link protection switching and EPS.
However, it is also possible that you have a standby link on the active NT and that in case of link failure, there‘s only a switchover to the standby link and not necessarily to the standby NT! In case the active NT unit fails, link protection and equipment protection become coupled.
To perform an independent switchover of the NT protection and uplink protection according to the location of the fault, you need an NT I/O.
Since there‘s no redundant NT I/O, the NT I/O becomes a single point of failure.
However, since the NT I/O contains mainly passive components with extremely low failure rate, the mean time between failures is extremely long (115 years!).
No need to protect NT I/O irrelevant to total system availability
NT switchover A B
outage data/forwarding plane ~ 2-5s
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load balancing
MAC layer redundancy
LAG
or ethernet switch
Single homing versus dual homing:
Dual Homing (Multi-Homed)
where a device is connected to the network via two independent access points (points of attachment). One access point is the primary connection; the other is a standby connection that is activated in case the primary connection fails.
Single Homing
where a device is connected to the network via ‘one’ (physical or logical) access point. In case of a link aggregation group, there’s only one logical group. The links in that group are not independent from each other!
802.3ad LACP = Link Aggregation Control Protocol
Link aggregation is used to increase the uplink capacity by bundling links.
Link aggregation offers a 1:N protection against link failures: if one of the links in the LAG fails, the other links take over (recovery time: 2-3 seconds – independent of the topology). The aggregate links falls back to a lower aggregate bandwidth then. Note that portion of traffic may get lost when fall-back to lower aggregate bandwidth.
LACP does not offer a protection against aggregation node failure. All links of a LAG go to the same aggregation node (e.g. an ethernet switch or a router), so if that aggregation node fails, nothing much can be done. Rapid spanning tree protocol can offer a solution for this. See further.
Multi-chassis link aggregation can also offer a solution (MC-LAG in 7x50). MC-LAG is transparent to the ISAM, so it’s beyond the scope of this course.
The links in a LAG work in loadsharing. There are no spare links in the group. All links are used for forwarding.
Link aggregation offers redundancy at the MAC layer. It is transparent for the upper layer. The LAG acts as one single physical link.
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ISAM is hot standby
NT B in hot-standby, no traffic
Triggers for a switchover:
pre-defined threshold for number of bad links in a LAG
Aggregation switch cold standby
“hot standby”
“cold standby”
Here you can have a single active link or a LAG as a single logical active link.
Switch-over from a failing LAG is only triggered if a certain number of bad links is reached (pre-defined threshold).
Hot-standby = automatic switchover without intervention of an operator.
Cold-standby = manual switchover – intervention of an operation is required to launch the switchover.
In this scenario there is a slow restoration.
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Protection against:
link failure
forced switchover to ‘full’ backup LAG possible
Supported for all forwarding models
RSTP
A
S
The slide shows a dual homing scenario where a device is connected to the network via two independent access points (points of attachment). One access point is the primary connection; the other is a standby connection that is activated in case the primary connection fails.
802.1w Rapid Spanning Tree Protocol runs over ISAM uplinks
RSTP runs over ISAM network links, not over subtending links or user links.
RSTP protects against:
RSTP doesn’t offer load balancing!
RSTP can be combined with link aggregation (LACP offers load balancing between the links in a LAG).
In that case, combined link and NT protection recommended (forced switch-over to “full” backup LAG instead of bandwidth drop upon failure of a defined number of links in the LAG – you can configure the threshold for switchover how many links in the LAG must always be operational?)
(Persistency of subscriber management characteristics in 7x50 nodes requires regular exchanging state info between both switches.)
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under-utilized links
better utilization of links
This is also a dual homing situation.
In case of RSTP only one Ethernet switch is active for all VLANs. The other Ethernet switch is standby for all VLANs.
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configure equipment protection-group <1> admin-status <lock/unlock> eps-quenchfactor <0..1440000>
By locking protection-group 1, you disable NT protection.
The EPS-quench factor is a timer value (in AWS expressed in seconds; in CLI in hundreds of seconds). This can be used to avoid toggling from NT-A to NT-B and back all the time. If there is a next failure before time out (t < quench timer), there will be no switchover.
Parameter
Link A Forced Active,
Link B Forced Active
APS Quench Factor in seconds (AWS CLI: in hundreds of seconds). A value equal to zero means the quenching mechanism is disabled.
EPS Administrative State Unlocked/Locked
Chain A Forced Active,
Chain B Forced Active
EPS Quench Factor in seconds (AWS CLI: in hundreds of seconds). A value equal to zero means the quenching mechanism is disabled.
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configure interface shub group 1 port 2
configure interface shub group 1 threshold 1
threshold = min. number of links that must be up
Default threshold = 0 (means no coupled LPS/EPS)
“hot standby”
Link & NT combined
If you omit this step, a link failure will never cause a switchover to the redundant NT!
Parameters:
Range: [1...7].
[no] threshold minimum number of links to be operational up in the group.
Range: [0...7]
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show equipment protection-group
show equipment protection-element
shows you which NT is in service and which one is in standby.
Alcatel-Lucent University Antwerp
Perform these exercises with CLI and AWS unless specified differently
Retrieving STP and LACP info / Creating LAG
1. What are the STP (or RSTP) parameters on the system (bridge parameters, e.g. hello time, forwarding delay…)?
Via Full CLI:
2.  Which Ethernet ports on the SHUB are in the forwarding state?
Via Full CLI:
Create LAG / Associate VLAN
For these exercises you’ll need to join forces with other groups!
1.  Subtend one ISAM to another one and create a link aggregation group between these two ISAMs. Create this LAG with AWS. Keep the default settings of the LAG.
AWS:
2.  Associate VLAN 150 to the aggregator port (i.e. the port in the LAG with the lowest port-id). Then check (via CLI) if VLAN 150 is also associated to the other port in the LAG.
AWS:
CLI:
3.  Is it possible to configure an aggregator port via CLI if the port is unconfigured?
CLI:
 
4.  Delete the LAG you created earlier with AWS and create it again with CLI (make sure they get an identical configuration). Use the same parameter values as the defaults in the AWS.
Then check the link aggregation configuration both via CLI and via AWS.
CLI:
5.  Retrieve link aggregation information from the LAG you created. What value do the LACP parameters have?
AWS:
CLI:
AWS:
CLI:
Exercises - Questions
NT redundancy
For these exercises you’ll need to join forces with other groups!
Insert 2 ECNT-A boards in an ISAM. Enable NT redundancy.
Wait until the NT-boards are synchronized (data is copied).
Configure a user channel and generate some traffic (e.g. some video multicast traffic – ask your teacher!).
Pull out the active NT (NT-A). NT-B will take over.
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