Route flaps & inconsistent origins
- Date: Fri, 30 Sep 1994 23:14:23 +0100
Hi,
we have had some problems recently apparently caused by route
flapping, and this inspired me to create a setup where I can log the
"route flaps of the world" and then do some perl programming to
analyze the debug logs. After about a day of programming I now have
a handfull of scripts which are able to post-process the output of
"debug ip bgp updates" on a Cisco router.
The router I am using to log this with has a direct peer with
nord-gw.nordu.net, that should be taken into account when looking at
the results (if I'm not mistaken, to some extent we'll see more
local problems than those on remote networks).
Processing yesterday's log (covering the interval Sep 29 04:05 to
Sep 30 04:05) produced the following "top 20" list of ASes injecting
route flaps as seen from our perspective:
Origin(s) flaps retr unrch dests AS AS Description
544 26070 264 266 109 544 The DataNet IP Service
719 17035 1 1 13 719 LANLINK autonomous system
1740 11880 2624 2623 186 1740 CERFNET
1717 7716 2645 2639 574 1717 RENATER
1221:297 6626 1155 1157 254 1221 AARNET-AS
1221:297 6626 1155 1157 254 297 NSN-UMD-AS
174:2149 5263 1705 1704 140 2149 PSINET-2
174:2149 5263 1705 1704 140 174 NYSERNET-AS
86 2890 489 488 113 86 SURANET-AS
2149:174 2604 769 769 178 2149 PSINET-2
2149:174 2604 769 769 178 174 NYSERNET-AS
2551 2354 318 318 174 2551 NETCOM-AS
372:297 2342 333 333 109 372 NSN-AMES-AS
372:297 2342 333 333 109 297 NSN-UMD-AS
297:1221 2168 337 346 95 1221 AARNET-AS
297:1221 2168 337 346 95 297 NSN-UMD-AS
372 2024 393 392 311 372 NSN-AMES-AS
701 1664 525 525 170 701 AlterNet
813 1589 617 615 83 813 CANET-ASN
2915 1488 391 391 83 2915 SPIN-NET
Legend:
"Origin(s)" are the AS or ASes seen as "origin" of routing updates
(essentially the last element in the logged path).
"flaps" is the sum of "retr" and the number of times the route was
updated (e.g. new path)
"retr" is the number of times a route was withdrawn (retracted)
"unrch" is the number of withdrawals which caused loss of
connectivity for a destination
"dests" is the number of destinations involved in route flaps
Excluded from this picture are any routes involving as-sets (there
are a number of routing flaps involving them as well, I'll see about
analyzing them separately...).
We are (as I write) trying to sort out the nordic-internal problem
involving the two on the top of the list.
One thing I want to draw to your attention, thogh, is the fact that
many destinations are apparently originated by more than one AS. I
was under the impression that this is an illegal or highly
undesireable configuration.
Attached below you will find a more detailed report showing the
number of times each individual path was announced for each of the
entries on the "top 20" list, I can also easily (on request) produce
a "per-network" report for any given AS.
It would seem that even beyond AS 1800 there are severe
instabilities in the routing.
Comments?
- Havard
PS. Maybe this should be redirected somewhere else than bgpd? nanog? iepg?
PPS. I am willing to give away my scripts to anyone asking (privately) for
them. Note that they're quick hacks and still evolving...
------------------------------
Origin(s) flaps retr unrch dests AS AS Description
544 26070 264 266 109 544 The DataNet IP Service
Count Path
244 2603 1759 544
12734 2603 1741 1759 544
12840 2603 1741 544
5 2603 1805 1800 1239 1280 701 1759 544
Origin(s) flaps retr unrch dests AS AS Description
719 17035 1 1 13 719 LANLINK autonomous system
Count Path
17045 2603 1741 719
1 2603 3224 2043 1128 286 790 719
Origin(s) flaps retr unrch dests AS AS Description
1740 11880 2624 2623 186 1740 CERFNET
Count Path
1029 2603 1805 1800 1133 690 1740
5071 2603 1805 1800 690 1740
937 2603 1755 1800 690 1740
1947 2603 1805 1800 701 690 1740
173 2603 1755 1800 701 690 1740
51 2603 1755 1800 1133 690 1740
82 2603 1805 1800 1239 1280 1740
15 2603 1805 1800 1133 1674 690 1740
5 2603 1755 1800 1133 1674 690 1740
15 2603 1755 1800 1239 1280 1740
Origin(s) flaps retr unrch dests AS AS Description
1717 7716 2645 2639 574 1717 RENATER
Count Path
2174 2603 3224 2043 1128 1755 1717
2486 2603 1755 1717
479 2603 3224 2043 1128 1133 1800 1755 1717
Origin(s) flaps retr unrch dests AS AS Description
1221:297 6626 1155 1157 254 1221 AARNET-AS
Count Path
1885 2603 1805 1800 690 372 1221
846 2603 1805 1800 701 690 372 1221
272 2603 1805 1800 1133 690 372 1221
32 2603 1755 1800 701 690 372 1221
31 2603 1755 1800 690 372 1221
4 2603 1755 1800 1133 690 372 1221
1 2603 1805 1800 1239 1240 690 372 1221
1 2603 1755 1800 1239 1240 690 372 1221
Origin(s) flaps retr unrch dests AS AS Description
1221:297 6626 1155 1157 254 297 NSN-UMD-AS
Count Path
582 2603 1805 1800 690 297
1035 2603 1805 1800 701 690 297
427 2603 1805 1800 1133 690 297
347 2603 1755 1800 701 690 297
6 2603 1755 1800 690 297
2 2603 1805 1800 1239 690 297
Origin(s) flaps retr unrch dests AS AS Description
174:2149 5263 1705 1704 140 2149 PSINET-2
Count Path
332 2603 1805 1800 1133 690 2149
397 2603 1805 1800 690 2149
154 2603 1805 1800 701 690 2149
58 2603 1755 1800 701 690 2149
93 2603 1755 1800 1133 690 2149
32 2603 1805 1800 1239 1240 690 2149
5 2603 1755 1800 1239 1240 690 2149
51 2603 1755 1800 690 2149
Origin(s) flaps retr unrch dests AS AS Description
174:2149 5263 1705 1704 140 174 NYSERNET-AS
Count Path
1432 2603 1805 1800 174
335 2603 1755 1800 174
229 2603 1805 1800 690 174
113 2603 1805 1800 701 690 174
108 2603 3224 2043 1128 1133 1800 174
43 2603 1755 1800 690 174
22 2603 1755 1800 701 690 174
86 2603 1805 1800 1239 1280 174
33 2603 1755 1800 1239 1280 174
25 2603 1805 1800 1133 690 174
8 2603 1805 1800 690 701 174
2 2603 1755 1800 690 701 174
1 2603 1755 1800 1133 690 174
Origin(s) flaps retr unrch dests AS AS Description
86 2890 489 488 113 86 SURANET-AS
Count Path
93 2603 1755 1800 86
857 2603 1805 1800 86
25 2603 1805 1800 690 279 86
352 2603 1805 1800 690 279 3561 86
84 2603 1805 1800 1133 690 279 3561 86
72 2603 1755 1800 690 279 3561 86
80 2603 1805 1800 701 690 86
674 2603 1805 1800 690 86
44 2603 1755 1800 690 86
32 2603 1805 1800 1239 1280 1957 690 279 3561 86
28 2603 1805 1800 1239 1280 1957 690 86
41 2603 1805 1800 1133 690 86
3 2603 1755 1800 1133 690 279 3561 86
3 2603 1755 1800 701 690 279 3561 86
5 2603 1755 1800 1239 1280 1957 690 279 3561 86
3 2603 1755 1800 690 279 86
2 2603 1805 1800 1133 690 279 86
12 2603 1805 1800 1239 1280 1957 690 279 86
3 2603 1805 1800 701 690 279 86
1 2603 1755 1800 701 690 86
2 2603 1755 1800 1239 1280 1957 690 86
1 2603 1755 1800 1239 1280 1957 690 279 86
Origin(s) flaps retr unrch dests AS AS Description
2149:174 2604 769 769 178 2149 PSINET-2
Count Path
220 2603 1805 1800 1133 690 2149
35 2603 1755 1800 1133 690 2149
116 2603 1805 1800 701 690 2149
215 2603 1805 1800 690 2149
37 2603 1755 1800 690 2149
27 2603 1755 1800 701 690 2149
8 2603 1805 1800 1239 1240 690 2149
2 2603 1755 1800 1239 1240 690 2149
2 2603 1805 1800 1133 1674 690 2149
Origin(s) flaps retr unrch dests AS AS Description
2149:174 2604 769 769 178 174 NYSERNET-AS
Count Path
709 2603 1805 1800 174
47 2603 1805 1800 1239 1280 174
118 2603 1805 1800 690 174
158 2603 1755 1800 174
18 2603 1755 1800 1239 1280 174
55 2603 3224 2043 1128 1133 1800 174
42 2603 1805 1800 701 690 174
10 2603 1755 1800 701 690 174
13 2603 1755 1800 690 174
4 2603 1805 1800 1133 690 174
Origin(s) flaps retr unrch dests AS AS Description
2551 2354 318 318 174 2551 NETCOM-AS
Count Path
708 2603 1805 1800 690 1321 2551
886 2603 1805 1800 2551
158 2603 1805 1800 701 690 2551
91 2603 1805 1800 690 2551
22 2603 1805 1800 701 690 1321 2551
93 2603 1755 1800 2551
30 2603 3224 2043 1128 1133 2551
20 2603 3224 2043 1128 1133 1800 2551
9 2603 1805 1800 1239 1280 2551
3 2603 1755 1800 701 690 2551
7 2603 1755 1800 690 1321 2551
2 2603 1755 1800 690 2551
3 2603 1805 1800 1133 690 1321 2551
3 2603 1755 1800 701 690 1321 2551
1 2603 1755 1800 1239 1280 2551
Origin(s) flaps retr unrch dests AS AS Description
372:297 2342 333 333 109 372 NSN-AMES-AS
Count Path
163 2603 1805 1800 1133 690 372
1067 2603 1805 1800 690 372
407 2603 1805 1800 701 690 372
66 2603 1755 1800 701 690 372
51 2603 1755 1800 1133 690 372
64 2603 1755 1800 690 372
Origin(s) flaps retr unrch dests AS AS Description
372:297 2342 333 333 109 297 NSN-UMD-AS
Count Path
182 2603 1805 1800 690 297
3 2603 1805 1800 1133 690 297
3 2603 1755 1800 690 297
3 2603 1805 1800 701 690 297
Origin(s) flaps retr unrch dests AS AS Description
297:1221 2168 337 346 95 1221 AARNET-AS
Count Path
567 2603 1805 1800 690 372 1221
253 2603 1805 1800 701 690 372 1221
97 2603 1805 1800 1133 690 372 1221
1 2603 1755 1800 701 690 372 1221
Origin(s) flaps retr unrch dests AS AS Description
297:1221 2168 337 346 95 297 NSN-UMD-AS
Count Path
93 2603 1755 1800 690 297
189 2603 1805 1800 690 297
249 2603 1805 1800 701 690 297
221 2603 1805 1800 1133 690 297
161 2603 1755 1800 701 690 297
Origin(s) flaps retr unrch dests AS AS Description
372 2024 393 392 311 372 NSN-AMES-AS
Count Path
315 2603 1805 1800 1133 690 372
515 2603 1755 1800 690 372
614 2603 1805 1800 690 372
136 2603 1805 1800 701 690 372
50 2603 1755 1800 701 690 372
1 2603 1755 1800 1133 690 372
Origin(s) flaps retr unrch dests AS AS Description
701 1664 525 525 170 701 AlterNet
Count Path
20 2603 1805 1800 1239 1280 701
590 2603 1805 1800 701
47 2603 3224 2043 1128 1133 1800 701
102 2603 1755 1800 701
59 2603 3224 2043 1128 1133 701
283 2603 1805 1800 690 701
39 2603 1805 1800 1133 1674 690 701
Origin(s) flaps retr unrch dests AS AS Description
813 1589 617 615 83 813 CANET-ASN
Count Path
588 2603 1805 1800 701 813
232 2603 1755 1800 701 813
39 2603 1805 1800 1239 1280 701 813
47 2603 3224 2043 1128 1133 1800 701 813
48 2603 3224 2043 1128 1133 701 813
10 2603 1805 1800 690 701 813
8 2603 1755 1800 1239 1280 701 813
1 2603 1755 1800 690 701 813
2 2603 1805 1800 1133 690 701 813
Origin(s) flaps retr unrch dests AS AS Description
2915 1488 391 391 83 2915 SPIN-NET
Count Path
121 2603 1805 1800 1133 690 2149 174 2713 2915
121 2603 1755 1800 1133 690 2149 174 2713 2915
375 2603 1755 1800 174 2713 2915
379 2603 1805 1800 174 2713 2915
12 2603 3224 2043 1128 1133 1800 174 2713 2915
44 2603 1805 1800 690 2149 174 2713 2915
39 2603 1805 1800 701 690 2149 174 2713 2915
1 2603 1805 1800 1239 1280 174 2713 2915
2 2603 1755 1800 1239 1280 174 2713 2915
3 2603 1755 1800 690 2149 174 2713 2915
|
you are here: RIPE -> RIPE Maillists > Archives
