CCNP Certification / BSCI Exam Tutorial: EIGRP Stuck-In-Active Routes
Computer and Technology - Passing the BSCI exam and earning your CCNP is about knowing the details, and when one thinks of EIGRP SIA routes, there will be lots of details to understand. A fast check of an internet search results for "troubleshoot SIA" will bring up some matches. Troubleshooting SIA routes are extremely challenging in which there is nobody reason they occur.
View the EIGRP topology table using the show ip eigrp topology command, and you may see a code next to every successor and feasible successor. A preferred misconception is that many of us want these routes to possess an "A" next to them - so they are active. That is what it is that we want, right? Active routes sound good, right?
Well, they sound good, but they are not. In case a route shows as Active inside the EIGRP topology table, that implies that DUAL happens to be calculating that route, then it‘s currently unusable. Each time a route is Passive (P), which means it is not being recalculated then it‘s a usable route.
A route shown as Active will probably be there for a really short period of the time you repeat the command, hopefully, that Active route has gone Passive. Sometimes that does not happen, though, and also the route becomes SIA - Stuck In Active.
A route becomes SIA each time a query goes unanswered for so long the neighbor relationship is reset. From experience, I will tell you just how troubleshooting SIA routes is even more of an art form when compared to a science, though there are four main reasons a route becomes SIA :
The link is unidirectional, therefore the query can't possibly be answered.
The queried router's resources are unavailable, generally because of high CPU utilization.
The queried router's memory is corrupt or otherwise not able to permit the router to answer the query.
The link between the two routers is of low quality, allowing only enough packets through to stay the neighbor relationship intact, but bad sufficient to permit the replies through.
To sum it up, routes become SIA each time a neighbor either does not answer a query, or either the query or reply took a wrong turn somewhere. I said it wasn't the simplest thing to troubleshoot!
I think it's enough all about CCNP Certification / BSCI Exam Tutorial: EIGRP Stuck-In-Active Routes. Thanks so much :)
CCNP Certification / BSCI Exam Tutorial: EIGRP Stuck-In-Active Routes
Well, they sound good, but they are not. In case a route shows as Active inside the EIGRP topology table, that implies that DUAL happens to be calculating that route, then it‘s currently unusable. Each time a route is Passive (P), which means it is not being recalculated then it‘s a usable route.
A route shown as Active will probably be there for a really short period of the time you repeat the command, hopefully, that Active route has gone Passive. Sometimes that does not happen, though, and also the route becomes SIA - Stuck In Active.
A route becomes SIA each time a query goes unanswered for so long the neighbor relationship is reset. From experience, I will tell you just how troubleshooting SIA routes is even more of an art form when compared to a science, though there are four main reasons a route becomes SIA :
The link is unidirectional, therefore the query can't possibly be answered.
The queried router's resources are unavailable, generally because of high CPU utilization.
The queried router's memory is corrupt or otherwise not able to permit the router to answer the query.
The link between the two routers is of low quality, allowing only enough packets through to stay the neighbor relationship intact, but bad sufficient to permit the replies through.
To sum it up, routes become SIA each time a neighbor either does not answer a query, or either the query or reply took a wrong turn somewhere. I said it wasn't the simplest thing to troubleshoot!
I think it's enough all about CCNP Certification / BSCI Exam Tutorial: EIGRP Stuck-In-Active Routes. Thanks so much :)
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