H3C S5820X SERIES High Availability Configuration Manual

Also see for s5800 series: Installation manual Instruction manual Command reference Quick start Troubleshooting guide

Contents

H3C S5820X SERIES High Availability Configuration Manual Manual pdf 71 page image

59RRPP timersWhen RRPP checks the link state of an Ethernet ring, the master node sends Hello packets out the primaryport according to the Hello timer, and determines whether its secondary port receives the Hello packetsbased on the Fail timer.• The Hello timer specifies the interval at which the master node sends Hello packets out the primaryport.• The Fail timer specifies the maximum delay between the master node sending Hello packets out theprimary port and the secondary port receiving the Hello packets from the primary port. If thesecondary port receives the Hello packets sent by the local master node before the Fail timer expires,the overall ring is in Health state. Otherwise, the ring transits into Disconnect state.• The Fast-Hello timer specifies the interval at which the master node sends Fast-Hello packets out theprimary port.• The Fast-Fail timer specifies the maximum delay between the master node sending Fast-Hellopackets out the primary port and the secondary port receiving the Fast-Hello packets from theprimary port. If the secondary port receives the Fast-Hello packets sent by the local master nodebefore the Fast-Fail timer expires, the entire ring is in the Health state. Otherwise, the ring transitsinto the Disconnect state.NOTE:In an RRPP domain, a transit node learns the Hello timer value and the Fail timer value on the master nodethrough the received Hello packets, ensuring that all nodes in the ring network are consistent in the twotimer settings. A transit node, however, cannot learn the Fast-Hello timer value and the Fast-Fail timervalue set on the master node through received Fast-Hello packets.How RRPP worksPolling mechanismThe polling mechanism is used by the master node of an RRPP ring to check the Health state of the ringnetwork.The master node sends Hello packets out its primary port periodically. These Hello packets travel througheach transit node on the ring in turn.• If the ring is complete, the secondary port of the master node will receive Hello packets before theFail timer expires, and the master node will keep the secondary port blocked.• If the ring is torn down, the secondary port of the master node will fail to receive Hello packetsbefore the Fail timer expires. The master node will release the secondary port from blocking dataVLANs and sending Common-Flush-FDB packets to instruct all transit nodes to update their ownMAC entries and ARP/ND entries.Link down alarm mechanismWhen a transit node, edge node, or assistant-edge node finds that any of its own ports belonging to anRRPP domain is down, it immediately sends Link-Down packets to the master node. Upon the receipt ofa Link-Down packet, the master node releases the secondary port from blocking data VLANs, and sendsCommon-Flush-FDB packet to instruct all the transit nodes, the edge nodes and the assistant-edge nodesto update their own MAC entries and ARP/ND entries. After each node updates its own entries, traffic isswitched to the normal link.