Support to set/unset Overload bit for ISIS Simulated and Emulated Routers without bringing down the ISIS session.

[SuryyaKrJana]

Feature Overview

• Related Issue: (Support to set/unset Overload bit for ISIS Simulated and Emulated Routers without bringing down the ISIS session. #480)
• Brief Description:
  User should be able to instruct the implementation to set or unset the Overload bit in the ISIS LSP without bringing down the session.
  When a router sets this bit, it tells other routers not to use it as a transit router.
  The router still forms IS-IS adjacencies, advertises its own prefixes,but other routers avoid routing through it during SPF calculations.

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Feature Details

• Redocly docs for this feature/branch

• New Locations
  Added update_overload_bit as a new choice on Action.Protocol.Isis.

• Dev-Snappi branch reference

• Example command to fetch the dev-snappi branch:

  go get github.com/open-traffic-generator/snappi/gosnappi@isis-overload-bit-control-ops
  

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Code snippets

...
  // --- SET overload bit ---
setAction := gosnappi.NewControlAction()
olBit := setAction.Protocol().Isis().UpdateOverloadBit()
olBit.SetRouterNames([]string{"simRtr1", "simRtr2"})
olBit.SetChoice(gosnappi.ActionProtocolIsisOverloadBitChoice.SET)  // Or .UNSET if needed.
if _, err := client.Api().SetControlAction(setAction); err != nil {
    t.Fatal(err)    
}
...

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[apratimmukherjee]

Looks good to me.