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Core Router Upgrade Status

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It has been a while since I've provided an update on the core router upgrade project, so here's the latest information.  Five of six routers have been replaced, with the remaining router likely to be replaced some early morning during the week of January 17th. The most challenging replacement thus far was in Engineering I, which took many hours and was a complete rip-and-replace project; many thanks to those who helped make it a success!

The primary links between the new core routers have been upgraded to 10Gb. It is likely the primary link between the campus core and border will be upgraded to 10Gb within the next couple of weeks.

The new routers have been operating largely as expected, and few people have noticed any changes associated with the migration. The implementation of access-control lists (ACLs) is slightly different, primarily due to differences in handling IP fragments and the removal of explicit "default deny" rules from existing ACLs. The use of explicit "default deny" rules had been for clarity while reading ACLs, but due to differences with IPv6 ACLs, we've updated ACLs to only use implicit "default deny" rules. It's a subtle change that has no functional impact, and will help maintain consistency between IPv4 and IPv6 ACLs.

There has been one unexpected reload of a core router, which occurred on Dec. 2nd. This reload was due to a software defect, and all relevant information was provided to Cisco. Although I have received preliminary information indicating the bug had been identified and fixed in code scheduled for release in January, I'm not entirely confident of the diagnostic process and have requested additional information. Fortunately, this defect has only caused one reload thus far.

As always, I really appreciate everyone's patience and support during this upgrade process. Please feel free to contact me at with any questions.