Facebook est très très très lent depuis Free lorsqu'on utilise IPv6 -> éventuellement le désactiver pour vérifier si ça vient de là.
Autre effet kiss-cool : quel DNS utilises-tu ?
Si on utilise son propre resolveur, on va aux US:
badmax@tao:~$ host www.facebook.com
www.facebook.com is an alias for star-mini.c10r.facebook.com.
star-mini.c10r.facebook.com has address 31.13.66.36
star-mini.c10r.facebook.com has IPv6 address 2a03:2880:f100:183:face:b00c:0:25de
badmax@tao:~$ traceroute 31.13.66.36
traceroute to 31.13.66.36 (31.13.66.36), 30 hops max, 60 byte packets
16  ae11.er1.dfw2.us.zip.zayo.com (64.125.20.66)  200.397 ms  202.164 ms  199.073 ms
17  64.124.196.38.IPYX-100687-820-ZYO.above.net (64.124.196.38)  199.875 ms  201.043 ms  201.496 ms
18  po103.psw01b.dft4.tfbnw.net (157.240.32.147)  198.995 ms po103.psw01d.dft4.tfbnw.net (157.240.32.149)  200.760 ms po103.psw01b.dft4.tfbnw.net (157.240.32.147)  199.490 ms
19  157.240.36.65 (157.240.36.65)  199.971 ms 157.240.36.7 (157.240.36.7)  197.639 ms  197.893 ms
20  edge-star-mini-shv-02-dft4.facebook.com (31.13.66.36)  211.571 ms  212.460 ms  210.922 ms
Si on utilise google DNS, on sort via Cogent puis Telia quelque part en Allemagne
badmax@tao:~$ host www.facebook.com 8.8.8.8
Using domain server:
Name: 8.8.8.8
Address: 8.8.8.8#53
Aliases: 
www.facebook.com is an alias for star-mini.c10r.facebook.com.
star-mini.c10r.facebook.com has address 31.13.93.36
star-mini.c10r.facebook.com has IPv6 address 2a03:2880:f11c:8083:face:b00c:0:25de
badmax@tao:~$ traceroute 31.13.93.36
traceroute to 31.13.93.36 (31.13.93.36), 30 hops max, 60 byte packets
16  po232.psw01d.fra3.tfbnw.net (157.240.35.95)  102.679 ms po241.psw01a.fra3.tfbnw.net (157.240.35.71)  102.455 ms po231.psw01c.fra3.tfbnw.net (157.240.32.219)  103.373 ms
17  msw1ak.01.fra3.tfbnw.net (173.252.66.113)  103.888 ms msw1ag.01.fra3.tfbnw.net (173.252.66.117)  112.427 ms msw1ac.01.fra3.tfbnw.net (173.252.66.121)  138.475 ms
18  edge-star-mini-shv-01-fra3.facebook.com (31.13.93.36)  113.411 ms  113.743 ms  110.383 ms
Si on utilise les DNS de Free, on  sort, certes, par Cogent mais on reste plus proche (CDG2->France ?)
badmax@tao:~$ host www.facebook.com 212.27.40.240
Using domain server:
Name: 212.27.40.240
Address: 212.27.40.240#53
Aliases: 
www.facebook.com is an alias for star-mini.c10r.facebook.com.
star-mini.c10r.facebook.com has address 179.60.192.36
star-mini.c10r.facebook.com has IPv6 address 2a03:2880:f11f:83:face:b00c:0:25de
badmax@tao:~$ traceroute 179.60.192.36
traceroute to 179.60.192.36 (179.60.192.36), 30 hops max, 60 byte packets
 8  edge-network.demarc.cogentco.com (149.6.164.254)  97.155 ms  98.388 ms  98.620 ms
 9  po101.psw01a.cdg2.tfbnw.net (31.13.28.3)  97.766 ms po101.psw01c.cdg2.tfbnw.net (157.240.34.241)  98.839 ms po101.psw01a.cdg2.tfbnw.net (31.13.28.3)  99.533 ms
10  173.252.67.79 (173.252.67.79)  107.757 ms msw1at.01.cdg2.tfbnw.net (204.15.20.221)  107.285 ms  107.734 ms
11  edge-star-mini-shv-01-cdg2.facebook.com (179.60.192.36)  107.956 ms  107.951 ms  107.945 ms