We have a DMVPN network with about 270 spokes (831) and 2 hubs (3825). We run EIGRP in all branch of the network.
We had experience many problems so far, but one of them seems to be related with the amount of traffic that is generated when some of our hub went down for about 15 to 30 seconds. All of our spokes start blinking on EIGRP but our VPN still up. Here is some of our messages that we have on Hub side (peer goodbye receive, stuck in active, hold timer expire). Our EIGRP timer are 5/15 but we tried 60/180, but we had the same issue.
We have a fiber 5Mb on one hub and the other hub have 10Mb fiber link.
This problem may happen because of various reasons like one of the neighbors reseting the other due to routes stuck in active, some router reporting a k-value mismatch, etc. Following links may help you
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...