IPv6 Peer Routing in VLT Domains Overview
VLT enables the physical links between two devices that are called VLT nodes or peers, and within a VLT domain, to be considered as a
single logical link to external devices that are connected using LAG bundles to both the VLT peers. This capability enables redundancy
without the implementation of Spanning tree protocol (STP), thereby providing a loop-free network with optimal bandwidth utilization.
IPv6 peer routing is supported on all the platforms that are compatible with IPv6 routing and support VLT. This functionality performs the
following operations:
•
Forwarding control traffic to the correct VLT node when the control traffic reaches the wrong VLT node due to hashing at the VLT LAG
level on the ToR.
•
Routing the data traffic which is destined to peer VLT node.
•
Synchronizing neighbor entries learned on VLT VLAN interfaces between the primary and secondary node.
•
Synchronizing the IP address of VLT VLAN interfaces between the VLT primary node and secondary node.
•
Performing routing on behalf of peer VLT nodes for a configured time period when a peer VLT node goes down.
When you configure Layer 3 VLT peer routing using the
peer-routing
command in VLT DOMAIN mode, it applies for both IPv4 and
IPv6 traffic in VLT domains. Layer 3 VLT provides a higher resiliency at the Layer 3 forwarding level. Routed VLT allows you to replace
VRRP with routed VLT to route the traffic from the Layer 2 access nodes. With neighbor discovery (ND) synchronization, both the VLT
nodes perform Layer 3 forwarding on behalf of each other.
The neighbor entries are typically learned by a node using neighbor solicitation (NS) and ND messages. These NS or neighbor
advertisement (NA) messages can be either destined to the VLT node or to any nodes on the same network as the VLT interface. These
learned neighbor entries are propagated to another VLT node so that the peer does not need to relearn the entries.
IPv6 Peer Routing
When you enable peer routing on VLT nodes, the MAC address of the peer VLT node is stored in the ternary content addressable memory
(TCAM) space table of a station. If the data traffic destined to a VLT node, node1, reaches the other VLT node, node2, owing to LAG-level
hashing in the ToR switch, it is routed instead of forwarding the packet to node1. This processing occurs because of the match or hit for
the entry in the TCAM of the VLT node2.
Synchronization of IPv6 ND Entries in a VLT Domain
Because the VLT nodes appear as a single unit, the ND entries learned via the VLT interface are expected to be the same on both VLT
nodes. VLT V6 VLAN and neighbor discovery protocol monitor (NDPM) entries synchronization between VLT nodes is performed.
The VLT V6 VLAN information must synchronize with peer VLT node. Therefore, both the VLT nodes are aware of the VLT VLAN
information associated with the peers. The CLI configuration and dynamic state changes of VLT V6 VLANs are notified to peer VLT node.
The ND entries are generally learned by a node from Neighbor advertisements (NA).
ND entries synchronization scenarios:
•
When you enable and configure VLT on both VLT node1 and node2, any dynamically learned ND entry in VLT node1 be synchronizes
instantaneously to VLT node2 and vice-versa. The link-local address also synchronizes if learned on the VLT VLAN interface.
•
During failure cases, when a VLT node goes down and comes back up all the ND entries learned via VLT interface must synchronize to
the peer VLT node.
Virtual Link Trunking (VLT)
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Содержание S4048T-ON
Страница 1: ...Dell Configuration Guide for the S4048 ON System 9 11 2 1 ...
Страница 148: ...Figure 10 BFD Three Way Handshake State Changes 148 Bidirectional Forwarding Detection BFD ...
Страница 251: ...Dell Control Plane Policing CoPP 251 ...
Страница 363: ... RPM Synchronization GARP VLAN Registration Protocol GVRP 363 ...
Страница 511: ...Figure 64 Inspecting the LAG Configuration Link Aggregation Control Protocol LACP 511 ...
Страница 512: ...Figure 65 Inspecting Configuration of LAG 10 on ALPHA 512 Link Aggregation Control Protocol LACP ...
Страница 515: ...Figure 67 Inspecting a LAG Port on BRAVO Using the show interface Command Link Aggregation Control Protocol LACP 515 ...
Страница 516: ...Figure 68 Inspecting LAG 10 Using the show interfaces port channel Command 516 Link Aggregation Control Protocol LACP ...
Страница 558: ...Figure 84 Configuring Interfaces for MSDP 558 Multicast Source Discovery Protocol MSDP ...
Страница 559: ...Figure 85 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 559 ...
Страница 560: ...Figure 86 Configuring PIM in Multiple Routing Domains 560 Multicast Source Discovery Protocol MSDP ...
Страница 564: ...Figure 88 MSDP Default Peer Scenario 2 564 Multicast Source Discovery Protocol MSDP ...
Страница 565: ...Figure 89 MSDP Default Peer Scenario 3 Multicast Source Discovery Protocol MSDP 565 ...
Страница 729: ...protocol spanning tree pvst no disable vlan 300 bridge priority 4096 Per VLAN Spanning Tree Plus PVST 729 ...
Страница 841: ...Figure 115 Single and Double Tag TPID Match Service Provider Bridging 841 ...
Страница 842: ...Figure 116 Single and Double Tag First byte TPID Match 842 Service Provider Bridging ...