Summarizes IPv6 path MTU controls, TCP MSS adjustment, neighbor discovery, IP address conflict resolution, VRF fallback, redirects, and local station MAC address configuration.
Use this chapter to control network stack traffic behavior, manage address conflicts, and configure IPv6 neighbor discovery and router-specific addressing functions.
The chapter organizes network stack traffic control and address management into these content areas:
|
Content area |
Included information |
|---|---|
|
IPv6 path MTU discovery |
Path maximum transmission unit (MTU) discovery behavior and the requirement to use TCP applications for path MTU discovery. |
|
TCP MSS adjustment |
TCP maximum segment size (MSS) adjustment and supported egress-interface requirements. |
|
IPv6 neighbor discovery |
Neighbor discovery behavior, neighbor solicitation messages, router advertisements, neighbor redirects, router advertisement suppression, and unicast router advertisement messages. |
|
IP address conflict resolution |
IP Address Repository Manager (IP ARM) conflict resolution policies, address repository behavior, and route tags for connected routes. |
|
VRF fallback and redirect |
Virtual routing and forwarding (VRF) fallback and redirect behavior and operational restrictions. |
|
Local station MAC addresses |
Local station media access control (MAC) addresses and the restriction for Cisco Silicon One Q100 ASICs. |
The topics progress from packet-size controls to IPv6 neighbor discovery, address conflict resolution, routing-instance fallback, and local station address configuration. Requirement and restriction information appears before the related configuration tasks.
Path MTU discovery for IPv6
Explains how IPv6 path MTU discovery dynamically identifies MTU differences along a path so the source can handle fragmentation, and describes its TCP-only support and key IPv6 MTU requirements.
TCP MSS adjustment
Explains how TCP MSS adjustment modifies the maximum segment size of transit IPv4 and IPv6 TCP SYN and SYN-ACK packets to keep flows within the interface MTU and prevent fragmentation during session establishment.
IPv6 neighbor discovery
Explains how IPv6 neighbor discovery operates on the local link to resolve neighbor addresses, verify reachability, and track neighboring routers by using ICMP-based discovery, advertisement, solicitation, and redirect messages.
IP address conflict resolution
Describes how IP Address Repository Manager (IPARM) detects address conflicts, applies conflict policies, supports connected-route tags, and uses Address Repository Manager data to select the active address.
VRF fallback and redirect
Describes how VRF fallback and redirect forward unmatched traffic through another VRF and use ABF rules to redirect IPv4 or IPv6 packets.
Local station MAC addresses for routers
Describes how a router-wide local station MAC address supports static ARP and dynamic ARP packets received across router interfaces on supported routers.