we have a test case from the operator that upon expiry of router lifetime the client device supposed to send Router solicitation message to the router. But this is not happening. is this because of some kernel configuration missing ? what could be the reason for this? Usually the router life time is infinite but for this particular test case it is of very low value of 240Seconds.Please help me.

  • Welcome to NE, we hope you find this a great community to contribute to and learn from. Please consider editing your question to add more details. You may find our Network Engineering Question Checklist can help you improve your question. For example: vendor/model of router, OS of client device, configuration from the router, etc – YLearn May 1 '15 at 0:07

Take a look at RFC 4861: Router Solicitations should only be sent when connecting to a link. After that the host just listens to the periodic Router Advertisements sent by the router.

If something goes wrong this is the router's fault for not sending a new RA in time, not the host's.

  • 1
    Actually, the switch could be blocking RAs (a good practice), but have that incorrectly set on the switch port to which the router connects (a common mistake). – Ron Maupin Apr 30 '15 at 16:13
  • @RonMaupin: good point, although in that case I would expect the first solicited RA to be dropped as well and that doesn't seem to be the case. But definitely a good setting to check! – Sander Steffann Apr 30 '15 at 16:15
  • Actually the test case is something like this1.Verify that the UE sends IPv6 Router Solicitation messages to the network and that the network responds. Configure the network so that the Router Advertisement message uses a "Valid Lifetime" of 5 minutes, a "Preferred Lifetime" of 5 minutes, and a "Router Lifetime" of 4 minutes. 2.Verify that the UE sends a Router Solicitation message to the PDN after between 3 and 4 minutes have elapsed from the receipt of the first Router Advertisement message. – sunil May 4 '15 at 6:21
  • The client device won't send another RS. That's not how the protocol works. – Sander Steffann May 4 '15 at 7:13

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