Although we use Features like spanning-tree portfast bpduguard and spanning-tree guard root, we had a Broadcast-Loop taking down Headquarters last month. As far as we can see it, using Storm-Control would have prevented this loop, which is why we now want to activate this Feature. But the Documentation which we found is a little bit thin. Open questions are for example:
- Where do we activate Storm-Control:
-- On each and every port in the Campus? Don't we risk then that a Storm in one Vlan which is Switched between our Distribution Switches takes down the Link between the Distr. and taking down the whole Access Branch?
-- On every Access-Port? Is there any way of enabling Storm-Control globally for a Switch or do we really have to blow up our Configs even more (not a problem, but a bit ugly nevertheless)
-- On all Uplinks from Distribution to Access-Switches (loosing one Access-Switch in the Case of a Storm would be acceptable for us)
- Does Storm-Control only work on incoming traffic? If a Storm comes in at gi0/1 and gets flooded to gi0/2, will gi0/2 also be taken down or only gi0/2' neighbour? If it is unidirectional and applying Storm-Control only to Uplinks is ok - should we enable it on both Sides of the Distribution<->Access Links or is it enough to enable it on the Distribution Side? From a Keeping-The-Configs-Sane-And-Clean-Side, this would be the most appealing way to do it.
- What are reasonable Levels for Storm-Control? We prefer a dregraded but still working network to false Shutdown-Reactions, even if we work with errdisable recovery - so we think of going with a very high level like 50%. Does this make any sense?
- What would be a good Level for Unicast Storm-Control? Is reacting on Unicast a good thing at all?
- Can we configure two levels: e.g. on 5% send a trap, on 50% go to Errdisable? Is there any way to send a syslog instead of a snmp trap?
What we look for is a Design Guideline for Storm-Control, but all we found were Configuration Guides. Is there any Document which would answer the questions above? Or does anyone in here have some good advices on Storm-Control
Thx in advance and Greetings from Switzerland
(Targeted Hardware: c6500 native ios, c3560, c2960)