Paul Ferguson wrote:
At 10:30 PM 3/3/97 -0600, Sean Donelan wrote:
From a single data point on my router, /24's currently account for 64% of the routing table entries and for 65% of the flapping prefixes. /16's account for 12% of the routing table entries, and 10% of the flapping prefixes. It doesn't appear to me there is a significant difference between flap behaivor of long prefixes and short prefixes. There are more long prefixes than short prefixes. But as a group they both tend to flap the same proportion of 2% of the routes within the group.
Sorry, I'm not convinced this is the case. There is not enough empirical evidence.
To back Paul up here.. Tests we have run would indicate that this is not _generally_ the case. I guess it depends on your point of viewing but we certainly see an inordinate amount of oscillation in the longer prefix ranges. (It also depends on the parameters you associate with certain prefixes of course ;-) (Sorry - no facts and figures to back that up) For instance, take this snapshot and note the /24 from within the 153.96 network. The flap column is the interesting one compared with other class Bs. This is not representative but gives a flavour of what we have been seeing. They are all from the same originator and it would not take a great amount of effort to apply a null0 tie down ! Network From Flaps Duration Reuse Path *> 143.222.116.0/24 146.188.31.193 4 01:21:32 702 701 3407 *d 146.1.0.0 146.188.31.193 10 00:32:21 00:23:20 702 701 3561 6196 6066 h 146.103.0.0 146.188.31.193 4 00:17:40 702 701 701 1239 4004 2611 *> 147.110.0.0 146.188.31.193 2 00:19:12 702 701 1280 2914 2905 *d 149.209.0.0 146.188.31.193 4 00:02:28 00:28:30 702 701 1800 1755 1273 5539 5430 * 150.61.0.0 146.188.31.193 1 00:00:26 702 701 3561 2521 4678 h 153.96.11.0/24 146.188.31.193 11 02:34:44 702 701 701 1800 1755 517 5501 h 153.96.96.0/22 146.188.31.193 12 02:34:44 702 701 701 1800 1755 517 5501 h 153.96.101.0/24 146.188.31.193 11 02:34:44 702 701 701 1800 1755 517 5501 h 153.96.104.0/22 146.188.31.193 12 02:34:44 702 701 701 1800 1755 517 5501 h 153.96.110.0/24 146.188.31.193 11 02:34:44 702 701 701 1800 1755 517 5501 h 153.96.120.0/23 146.188.31.193 12 02:34:44 702 701 701 1800 1755 517 5501 h 153.96.149.0/24 146.188.31.193 11 02:34:44 702 701 701 1800 1755 517 5501 h 153.96.176.0/22 146.188.31.193 12 02:34:44 702 701 701 1800 1755 517 5501 h 153.96.236.0/22 146.188.31.193 12 02:34:51 702 701 701 1800 1755 517 5501 h 153.96.243.0/24 146.188.31.193 11 02:34:51 702 701 701 1800 1755 517 5501 *> 155.141.0.0 146.188.31.193 3 00:14:46 702 701 1800 668 *> 155.148.0.0 146.188.31.193 3 00:14:46 702 701 1800 668 *> 156.6.0.0 146.188.31.193 3 00:14:48 702 701 1800 668 *> 156.36.0.0 146.188.31.193 2 00:19:21 702 701 1280 2914 --Tony