Tài liệu Intermittent broadcast storms ppt

Here is the top bugs instructors like to use from someone whose been on the inside
and has friends still there.

1. Config registers.
Know them by heart. They laugh when a candidate fails
and leaves in frustration because of the surprising results they're getting during
troubleshooting, and it won't be the obvious, and it can happen to more than
one router.

2.Hold downs and NBMA.
They're amazed how many guys fail when they
manipulate the timers. Be sure you know the hello intervals, updates,
hold downs, ect on the various protocols between medias such as NBMA
and broadcast, so you don't fall into that trap.

3. Intermittent broadcast storms
A tough one, especially when it's gone as fast as
it came before you can bring your guns to bare. One minute a pc is locked up
on network neighborhood, the next everything's fine. Windows NT is good for this,
but what about coming from a router or a switch. You know the deal, divide and
conquer. Setting broadcast supression on those port to see which broadcasts got
dropped comes in handy.

4. Summarization, summarization, summarization. If some of those hosts are not
being reached from outside an ASBR, look for this.

5. Wrong BGP Paths. With the web so popular, it's common bug. ( If you're
going to the lab in NC, study BGP reflector. This lab has just been added after
finding out this info.

6. NAT and Pat. Another common bug.

7. Access-lists. Sounds simple. Troubleshooting a missconfigured list to exclude
a subnet, a protocol, or a host: instructors say"too easy". They like lists that
excludes 1/4 of a subnet, or creating an environment where an app gets through
sometimes, other tomes it's blocked.

8. The first thing you do when you configure anything is password all your vty
ports, because if you don't , they'll go right in the back door and change
your configs on you. Too many guys failed because they forgot to do this simple
task. The instructors hold network security in high regards.