Dear all,
We have a strange behavior when we used google DNS servers to resolve google apps DNS objects through our private DNS environment.
First of all, the context :
Our company use Google apps (gmail, drive, docs, sites...) since 2 years and we followed google recommendation. It mean "avoid proxy devices with google apps traffic". We do that with some line inside a PAC file where we put in direct mode google apps based on these criterion :
//Exception Google
if (isInNet(resolved_ip, "216.239.32.0", "255.255.224.0")||
isInNet(resolved_ip, "64.233.160.0", "255.255.224.0")||
isInNet(resolved_ip, "66.249.80.0", "255.255.240.0")||
isInNet(resolved_ip, "72.14.192.0", "255.255.192.0")||
isInNet(resolved_ip, "209.85.128.0", "255.255.128.0")||
isInNet(resolved_ip, "66.102.0.0", "255.255.240.0")||
isInNet(resolved_ip, "74.125.0.0", "255.255.0.0")||
isInNet(resolved_ip, "64.18.0.0", "255.255.240.0")||
isInNet(resolved_ip, "207.126.144.0", "255.255.240.0")||
isInNet(resolved_ip, "173.194.0.0", "255.255.0.0")
)
)
{return proxy_no;}
}
Public IP range used by google apps are find from this command :
Address: 8.8.8.8
Réponse ne faisant pas autorité :
These IP range are authorized in "Direct" through all our internet firewall (about 20 for the moment but more and more in the future).
We followed these recommendations from google :
THE ISSUE :
4 months ago (during one or 2 days) :
After slowly issue (proxy overloaded) in Swiss (with Swisscom), we found this fact :
Server: 8.8.8.8
Address: 8.8.8.8#53
Non-authoritative answer:
Address: 193.134.255.153
Address: 193.134.255.148
A "whoise IP" gave me this result :
descr: Google GGC
origin: AS3303
mnt-by: CH-UNISOURCE-MNT
source: RIPE # Filtered
Yesterday, from France (with Completel), I identified the same issue but with an other public IP range :
Address: 8.8.8.8
Réponse ne faisant pas autorité :
Addresses: 2a00:1450:4007:80b::2000
216.58.211.78
216.58.211.64
Address: 213.244.0.15
DNS request timed out.
timeout was 2 seconds.
Réponse ne faisant pas autorité :
Addresses: 2a00:1450:4007:807::1003
173.194.40.96
173.194.40.104
173.194.40.103
173.194.40.102
173.194.40.105
173.194.40.101
173.194.40.110
173.194.40.100
173.194.40.97
173.194.40.98
173.194.40.99
A "whoise IP" gave me this result :
NetRange: 216.58.192.0 - 216.58.223.255
NetName: GOOGLE
NetHandle: NET-216-58-192-0-1
Parent: NET216 (NET-216-0-0-0-0)
NetType: Direct Allocation
OriginAS: AS15169
Organization: Google Inc. (GOGL)
SO, QUESTIONS :
For the moment, I keep the position to not use Google DNS servers because there is too many risk with Google Apps and this kind of behavior is not compliant with network google recommendation (for me, here, we have an incoherence in the Google Network recommendation, they recommand to avoid proxy but we don't have visibility on public IP used...).
8.8.8.8 is anycast IP so, it could be a benefits in term of geolocalisation, in term of exploitation to simplify our settings through EMEA and in term of performance (I already saw better reply from Google DNS server than provider DNS server). But, I can not recommand this with this kind of behavior for the moment.
Best regards,