filtering long prefixes
Sean Doran
smd at icp.net
Thu Sep 21 22:58:02 UTC 1995
Yup, 206.12/16 is the first area that jumped out at me after
noting that many /19s and longer under 206/8 can easily be aggregated
under /16s or better.
Is Herb Kugel still the IP registrar for Canada?
One thing to note right now is that because of the 206.12/16
prefix itself, traffic to subnets of 206.12/16 that aren't heard
within SprintLink will get delivered to InternetMCI, which announces
the /16 to us.
Unless InternetMCI changes its configurations to do similar
filtering, they may end up dumping traffic for subnets of
206.12/16 onto the MAE or NAP where they receive it from AS 1239.
If they change the configuration, then they will follow the
longest prefixes they have, which may be the /16, and deliver
the traffic appropriately.
At that point, some traffic for non-CA*Net sites will hit
CA*Net, and whether it gets delivered or not deepends on
local connectivity within Canada. It'll work handily for
sites that peer with CA*Net or BCNet (which seems to be
the CA*Net member that announces 202.12/16).
Such is the price of geographical allocation.
Something to be considered by the folks who recommend that approach.
Sample traceroutes follow.
Sean.
P.S.: This raises an interesting point that has been raised
in private email to various folks concerned with
206/8: if local aggregation cannot be done, then
I suppose it would be easy enough to have some
well-connected provider somewhere generate a prefix
that is 18 bits long or shorter and deliver to the subnets
appropriately. Whether this would be done out of the goodness
of that provider's well-connected heart, or for a fee, is
an interesting question.
- --
: chops.icp.net-MHRC ; traceroute 206.12.101.1
traceroute to 206.12.101.1 (206.12.101.1), 30 hops max, 40 byte packets
1 sl-hrn-1-E5.sprintlink.net (199.0.55.1) 5.006 ms 5.927 ms 4.424 ms
2 sl-fw-8-S3/0-T1.sprintlink.net (144.228.38.61) 44.53 ms 40.226 ms 40.043 ms
3 sl-fw-6-F0/0.sprintlink.net (144.228.30.6) 41.199 ms 39.808 ms 39.474 ms
4 sl-ana-1-H2/0-T3.sprintlink.net (144.228.10.30) 73.9 ms 63.938 ms 63.856 ms
5 sl-ana-2-F0/0.sprintlink.net (144.228.70.2) 67.004 ms 63.935 ms 64.846 ms
6 sl-stk-6-H2/0-T3.sprintlink.net (144.228.10.25) 75.445 ms 115.007 ms 130.088 ms
7 sl-mae-w-H1/0-T3.sprintlink.net (144.228.10.46) 120.591 ms 75.239 ms 74.903 ms
8 mae-west.SanFrancisco.mci.net (198.32.136.12) 106.208 ms 84.766 ms 84.696 ms
9 mae-west.net99.net (198.32.136.16) 91.729 ms 81.322 ms 185.042 ms
10 seattle-1-E0.net99.net (204.157.228.50) 121.525 ms 119.73 ms 118.15 ms
11 cortland/C4-0/T1.net99.net (204.157.10.50) 123.203 ms 123.439 ms 119.942 ms
12 cyber/westnet.cyberstore.ca (199.45.68.6) 136.102 ms 125.274 ms 136.192 ms
13 vanrs001.cyberstore.ca (199.45.66.251) 106.903 ms 115.651 ms 107.9 ms
14 sl-chi-4-S3/2-T1.sprintlink.net (144.228.54.37) 103.651 ms 106.569 ms 106.307 ms
15 sl-chi-6-F0/0.sprintlink.net (144.228.50.6) 153.965 ms 221.79 ms 224.213 ms
16 sl-chi-nap-H1/0-T3.sprintlink.net (144.228.56.10) 106.431 ms 105.126 ms 107.66 ms
17 aads-F.mci.net (198.32.130.227) 111.367 ms 111.693 ms 109.686 ms
18 border2-hssi1-0.Chicago.mci.net (204.70.25.5) 104.894 ms 109.886 ms 106.115 ms
19 core-fddi-1.Chicago.mci.net (204.70.3.81) 136.612 ms 159.454 ms 245.642 ms
20 core1-hssi-2.NorthRoyalton.mci.net (204.70.1.94) 104.756 ms 109.119 ms 109.809 ms
[ and goes around in circles, because this prefix doesn't seem to be
pointed at anything...]
: chops.icp.net-MHRC ; traceroute 206.12.117.1
traceroute to 206.12.117.1 (206.12.117.1), 30 hops max, 40 byte packets
1 sl-hrn-1-E5.sprintlink.net (199.0.55.1) 4.724 ms 2.708 ms 3.42 ms
2 sl-fw-8-S3/0-T1.sprintlink.net (144.228.38.61) 43.637 ms 39.825 ms 39.304 ms
3 sl-fw-6-F0/0.sprintlink.net (144.228.30.6) 52.659 ms 42.551 ms 41.278 ms
4 sl-ana-1-H2/0-T3.sprintlink.net (144.228.10.30) 71.023 ms 64.961 ms 63.816 ms
5 sl-ana-2-F0/0.sprintlink.net (144.228.70.2) 67.1 ms 63.442 ms 64.288 ms
6 sl-stk-6-H2/0-T3.sprintlink.net (144.228.10.25) 76.548 ms 72.84 ms 73.785 ms
7 sl-mae-w-H1/0-T3.sprintlink.net (144.228.10.46) 79.905 ms 75.496 ms 74.788 ms
8 mae-west.SanFrancisco.mci.net (198.32.136.12) 89.111 ms 87.641 ms 217.096 ms
9 t3-0.enss144.t3.nsf.net (192.203.230.253) 107.938 ms 95.99 ms 96.662 ms
10 t3-3.cnss8.San-Francisco.t3.ans.net (140.222.8.4) 99.96 ms 95.953 ms 109.311 ms
11 t3-1.cnss88.Seattle.t3.ans.net (140.222.88.2) 112.245 ms 113.35 ms 111.012 ms
12 cnss93.Seattle.t3.ans.net (140.222.88.197) 127.135 ms 114.558 ms 114.102 ms
13 192.103.70.62 (192.103.70.62) 118.403 ms 122.704 ms 122.746 ms
14 192.197.172.25 (192.197.172.25) 141.079 ms 135.193 ms 130.761 ms
15 206.12.117.98 (206.12.117.98) 227.997 ms 144.418 ms 133.641 ms
16 206.12.117.98 (206.12.117.98) 129.806 ms !H !H
[ok]
: chops.icp.net-MHRC ; traceroute 206.12.154.1
traceroute to 206.12.154.1 (206.12.154.1), 30 hops max, 40 byte packets
1 sl-hrn-1-E5.sprintlink.net (199.0.55.1) 4.548 ms 3.199 ms 4.35 ms
2 sl-fw-8-S3/0-T1.sprintlink.net (144.228.38.61) 41.879 ms 40.927 ms 41.546 ms
3 sl-fw-6-F0/0.sprintlink.net (144.228.30.6) 46.436 ms 41.338 ms 40.558 ms
4 sl-ana-1-H2/0-T3.sprintlink.net (144.228.10.30) 66.792 ms 64.395 ms 63.976 ms
5 sl-ana-2-F0/0.sprintlink.net (144.228.70.2) 66.02 ms 63.443 ms 64.024 ms
6 sl-stk-6-H2/0-T3.sprintlink.net (144.228.10.25) 75.06 ms 74.22 ms 71.917 ms
7 sl-mae-w-H1/0-T3.sprintlink.net (144.228.10.46) 77.256 ms 76.258 ms 74.408 ms
8 mae-west.SanFrancisco.mci.net (198.32.136.12) 88.265 ms 86.16 ms 85.054 ms
9 border2-hssi2-0.SanFrancisco.mci.net (204.70.33.13) 86.393 ms 87.029 ms 84.88 ms
10 borderx2-fddi0-0.SanFrancisco.mci.net (204.70.3.164) 87.03 ms 84.509 ms 87.846 ms
11 core2-fddi-1.SanFrancisco.mci.net (204.70.158.65) 86.86 ms 87.3 ms 85.111 ms
12 core1-hssi-2.Sacramento.mci.net (204.70.1.146) 89.264 ms 86.404 ms 87.708 ms
13 core-hssi-3.Seattle.mci.net (204.70.1.150) 98.816 ms 90.917 ms 92.826 ms
14 border2-fddi-0.Seattle.mci.net (204.70.3.146) 92.045 ms * *
15 fonorola-internet.Seattle.mci.net (204.70.53.22) 103.243 ms 96.078 ms 104.548 ms
16 IceOnline-GW.vancouver.fONOROLA.net (198.53.80.250) 102.898 ms 103.595 ms 109.361 ms
17 router.iceonline.com (204.191.208.2) 104.766 ms 114.713 ms 107.489 ms
18 cisco.iceonline.com (204.191.208.1) 101.188 ms 102.015 ms 104.648 ms
19 router.iceonline.com (204.191.208.2) 120.781 ms 106.341 ms 102.491 ms
20 cisco.iceonline.com (204.191.208.1) 114.748 ms * 104.974 ms
21 router.iceonline.com (204.191.208.2) 112.519 ms 107.59 ms 110.332 ms
[again, not really aimed at anything]
SL-CHI-6>trace 206.12.229.1
Type escape sequence to abort.
Tracing the route to 206.12.229.1
1 sl-chi-nap-H1/0-T3.sprintlink.net (144.228.56.10) 4 msec 0 msec 0 msec
2 aads-F.mci.net (198.32.130.227) [AS 3561] 28 msec 28 msec 28 msec
3 border2-hssi1-0.Chicago.mci.net (204.70.25.5) [AS 3561] 28 msec 76 msec 212 msec
4 core-fddi-1.Chicago.mci.net (204.70.3.81) [AS 3561] 28 msec 28 msec 24 msec
5 core1-hssi-2.NorthRoyalton.mci.net (204.70.1.94) [AS 3561] 28 msec 28 msec 28 msec
6 core1-hssi-3.WestOrange.mci.net (204.70.1.102) [AS 3561] 28 msec 28 msec 28 msec
7 204.70.1.97 [AS 3561] 28 msec 28 msec 28 msec
8 border2-fddi-0.NewYork.mci.net (204.70.3.18) [AS 3561] 24 msec 28 msec 28 msec
9 sprint-nap.NewYork.mci.net (204.70.45.6) [AS 3561] 64 msec 28 msec 28 msec
10 fd-0.enss218.t3.ans.net (192.157.69.4) 28 msec 24 msec 28 msec
11 t3-3.cnss32.New-York.t3.ans.net (140.222.32.4) [AS 690] 32 msec 32 msec 32 msec
12 t3-0.cnss48.Hartford.t3.ans.net (140.222.48.1) [AS 690] 40 msec 36 msec 40 msec
13 t3-2.cnss43.Cleveland.t3.ans.net (140.222.43.3) [AS 690] 52 msec 52 msec 48 msec
14 t3-1.cnss27.Chicago.t3.ans.net (140.222.27.3) [AS 690] 60 msec 56 msec 56 msec
15 t3-1.cnss96.Denver.t3.ans.net (140.222.96.2) [AS 690] 84 msec 84 msec 84 msec
16 t3-0.cnss88.Seattle.t3.ans.net (140.222.88.1) [AS 690] 100 msec 100 msec 100 msec
17 cnss93.Seattle.t3.ans.net (140.222.88.197) [AS 690] 100 msec 100 msec 96 msec
18 192.103.70.62 [AS 1331] 148 msec 308 msec 152 msec
19 192.197.172.2 [AS 1691] 176 msec 152 msec 128 msec
20 192.197.174.34 [AS 577] 128 msec 120 msec 164 msec
21 pme0.awinc.com (199.175.168.240) [AS 1691] 128 msec 196 msec 184 msec
22 pmeMsync.awinc.com (199.175.169.150) [AS 1691] 240 msec 264 msec 256 msec
23 * * *
24 * * *
[thud]
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