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Preliminary Measurement Results on Highly Active Prefixes in BGP Routing. Ricardo Oliveira, Rafit Izhak-Ratzin, Beichuan Zhang, Lixia Zhang UCLA November 9, 2004. Why measure Highly Active (HA) prefixes. Observations from some previous work
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Preliminary Measurement Resultson Highly Active Prefixes in BGP Routing Ricardo Oliveira, Rafit Izhak-Ratzin, Beichuan Zhang, Lixia Zhang UCLA November 9, 2004
Why measure Highly Active (HA) prefixes • Observations from some previous work • "BGP routing stability of popular destinations" by Rexford et al, IMW 2002 • "Observation and analysis of BGP behavior under stress" by Wang et al, IMW 2002 • Is this HA phenomenon common among all ASes? • How long has it existed? • And who are the HAs? UCLA
Approach • Got BGP logs from RouteViews (RV) (zebra box) • Dataset: 10/26/01 — 8/31/04 • Removed update messages potentially due to BGP session reset • over this (near) 3-year time period • looked through all the updates from 4 peers • Looked through all the updates from all 33 peers for 2 random months Peer RV multihop BGP peering session UCLA
How to define HA UCLA
HA phenomenon is persistent over time 1/1/03 Blaster(8/11/03) slammer UCLA
# of HAs seen by each of 33 peers (5/04) • Fig 5 UCLA
# of HAs seen by each of 33 peers (10/04) 146370 (peer 12.0.1.63) UCLA
# of HAs seen by multiple peers (May 1-5) 5/3/04 UCLA
More on common HAs seen in May04 • The origin Ases of the common HAs: 144 common HAs came from 58 origin ASes • AS5786: 39; AS11139: 18; the rest: originated1 - 4 • Lifetime of these common HAs UCLA
How many days a HA active? > 700 UCLA
Prefix length distribution of HAs with lifetime > 20 days UCLA
Some /8's: Stability or lack of it[10/26/01-- 8/31/04] # of highly active days 129.250.0.11 144.228.241.81 199.74.221.1 204.42.253.253 3.0.0.0/8 204 136 186 175 61.0.0.0/8 148 71 178 15 62.0.0.0/8 39 1 11 1 63.0.0.0/8 120 31 70 83 64.0.0.0/8 62 4 56 48 65.0.0.0/8 20 1 41 6 67.0.0.0/8 72 0 0 11 80.0.0.0/8 383 297 299 314 81.0.0.0/8 157 4 4 93 82.0.0.0/8 144 34 128 28 UCLA
Does the set of HAs change over time? End of dataset (8/31/04) UCLA
Who are those persistent HAs? • Case 1: BGP Beacons • 1 update/2-hour, interleaving announce/withdrawal • 12 updates/day generated from the origin UCLA
Slow convergence: one example Took almost 3 min beacon 195.80.227/24 seen at one peer Time type AS path 1099000967 W 1099008081 A 1239 3257 3257 28747 12654 1099008111 A 1239 8928 25232 12654 1099015221 A 1239 3356 25232 12654 1099015247 A 1239 701 6762 12654 1099015304 A 1239 701 6762 12654 (community change) 1099015329 A 1239 7018 8220 513 3320 702 13030 12654 1099015364 A 1239 7018 8220 513 3320 702 13030 12654 1099015387 W 30 sec UCLA
slow convergence: another example 8 updates in 53 sec beacon 195.80.227/24 seen at another peer Time type AS path 1099245759 W 1099252820 A 2914 12654 1099260008 A 2914 6453 12654 1099260009 A 2914 13237 12654 1099260027 A 2914 6453 12654 1099260031 A 2914 6453 12654(duplicate) 1099260032 A 2914 6453 12654 1099260035 A 2914 6453 12654 1099260042 A 2914 6453 12654 1099260061 W MRAI timer off UCLA
Prefix #days Average active #updates/day +-----------------+-----+-----+---+---+ | 195.80.225.0/24 | 702 | 97 |622|114| | 195.80.229.0/24 | 700 | 105 |606|100| | 195.80.227.0/24 | 699 | 81 |579| 92| | 192.135.183.0/24| 676 | 34 |418| 92| | 195.80.231.0/24 | 612 | 49 |277| 69| | 195.80.226.0/24 | 533 | 79 |124| 68| | 195.80.235.0/24 | 134 | 65 | 72| 66| +-----------------+-----+-----+---+---+ Other beacons' update counts[10/26/01-- 8/31/04] #HA days UCLA
Another example: a small set of /24 HAs • Seen by one peer: some # /24's from Universite de Brest • Highly active since Dec'01 (stopped before Octobor'04) • May'04: 9 of 33 RV peers observed high update counts during the month +----------------+---------+---------+---------+ | peers | average | maximum | minimum | +----------------+---------+---------+---------+ | 144.228.241.81 | 336 | 424 | 263 | | 12.0.1.63 | 367 | 431 | 250 | | 206.24.210.26 | 270 | 433 | 53 | | 204.42.253.253 | 163 | 490 | 59 | | 147.28.255.1 | 174 | 491 | 61 | | 4.68.0.243 | 456 | 571 | 315 | | 129.250.0.11 | 225 | 596 | 79 | | 193.251.128.22 | 533 | 603 | 370 | | 208.51.113.254 | 284 | 713 | 79 | +----------------+---------+---------+---------+ UCLA
Yet another example ofhighly active, long lasting prefix Early 2003 The origin AS generated >1000 updates/day for 8 days (>2000 for 3 days) UCLA
Yet another example • one /24 prefix was active for 12 consecutive days, 6011 updates/day average ( 11 sec/update) • The peaks: > 12,000 updates on 11/6/03 • Looked all the 33 peers on 11/6/03: 6 classified this prefix as HA • 2 routers saw 12K, 8K updates respectively • One router observed flapping between 2 routes • the other : flapping among 5 routes • The other 4 peers saw 49-59/day • the rest 27 peers didn’t catch this prefix as HA UCLA
What kinds of updates? Seen by one peer, October 2004: 188.1.0.0/16: HA for 254 days [Oct'01-Aug'04]. 66.150.140.0/23: HA for 542 days [Oct'01-Aug'04]. UCLA
Ongoing Effort • Your suggestions go here • Continue the monitoring effort • Identify the causes of HAs • for prefixes that are originated by RV's direct peers, comparing local view and remote views of prefixes to better identify slow convergence and damping effect UCLA