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1.2.21 Maintenance windows
Maintenance works are on everybody’s agenda in current fast paced and continuously evolving networks. During maintenance network engineers are very busy and will welcome any help their systems can offer in carrying out those works with the least amount of headaches. IRP is clearly not in the top of network engineer’s priorities and asking to suspend or shutdown a provider immediately before a maintenance window starts and restart the provider back once the maintenance works end is not very helpful if not even annoying.
Instead IRP offers the facility to plan maintenance windows in advance. Knowing when a maintenance window starts and ends, IRP excludes that specific provider link from either performance optimization or bandwidth control. More so, IRP has the capability to reshape the traffic flowing in and out of a network to anticipate any downtime on a link.
Setting a maintenance window by router sets each of the providers on the router with a maintenance window of their own.Properly configured maintenance windows allows IRP time to move most of the outbound traffic and deflect most of inbound traffic away from the provider link that is scheduled for maintenance. Having only a small fraction of traffic or none at all on the maintenance link before the downtime starts avoids any (shall we say, catastrophic) spikes, possible overloads and consequently unpredictable behavior of the remaining live network equipment.
Specifically the following applies:
- a maintenance window is configured in advance and can be removed/revised at any time,
- a maintenance window sets details for single provider. If needed multiple maintenance windows can be setup and even overlapping maintenance windows are OK.
- IRP highlights maintenance windows in IRP’s Frontend sidebar so that it is easy to spot current maintenance window status.
- optionally IRP can preserve existing improvements so that once the maintenance window ends improvements are reimplemented. It is advised that this feature is used only when the maintenance window is very short (a few minutes).
- an unloading period can be setup. During unloading IRP actively re-routes outbound prefixes through other available providers. While IRP is able to make most of the unloading improvements fast consideration shall be given to the announcement rate limitations setup in Bgpd in order for all the improvements to reach network routers in time for maintenance window starting time.
- a prepend time can be setup. This is only applicable if Inbound optimization is operational. If this time is setup then IRP will prepend configured inbound prefixes with the maximum allowed number of prepends through the provider link under maintenance in order to deflect inbound traffic towards other providers. Refer to Inbound bandwidth optimization for more details about Inbound optimization.
Refer Maintenance windows for details how to configure, review, create, edit, delete maintenance windows.