I am trying to understand NTP more by trying to have a few routers connected in gns3 having various types of NTP relationships as below:
* Note: "RT32 peer (passive)" for RT29 means RT32 configured to peer to RT29 unidirectionally, ie, no peer configuration done on RT29.
Few questions I have as below:
1) The routers keep flapping from one relationship to another, ex, RT29 at one point says RT01 as "sane, valid", then few minutes later, says RT01 as "insane, invalid" while RT32 as "sane, valid". Is this normal? If not, where should I check?
2) If everything is working correctly, should all sources within a single router be shown as "sane, valid"? I have one particular router (RT31) that shows both relationships as "sane, valid" at one point, with <#sh ntp asso> showing one as "sys.peer" and the other as "candidate".
3) What exactly does "sane, invalid" mean? Where should I begin to check what exactly is causing this?
Thank you.
