Fix flakyness in TestDockerNetworkInternalMode
Fix flakyness in TestDockerNetworkInternalMode

Instead of waiting for the DNS to fail, try to access
a specific external IP and verify that 100% of the pakcets
are being lost.

Signed-off-by: Flavio Crisciani <59eae1aa696b1b39cd87a38bdba3f0b2630647f9@docker.com>

YuPengZTE/docker,kojiromike/docker,cpuguy83/docker,dims/docker,yongtang/docker,flavio/docker,dmcgowan/docker,kojiromike/docker,kolyshkin/moby,konstruktoid/docker-upstream,Mokolea/docker,jthelin/docker,allencloud/docker,gnailuy/docker,unclejack/docker,konstruktoid/docker-upstream,SvenDowideit/docker,Ramzec/docker,paralin/docker,dims/docker,ibuildthecloud/docker,maxamillion/docker,Ramzec/docker,jwhonce/docker,laijs/moby,laijs/docker,mahak/docker,rremer/moby,konstruktoid/docker-1,maxamillion/docker,trebonian/docker,KarthikNayak/docker,gnailuy/docker,mikebrow/docker,paralin/docker,ibuildthecloud/docker,moby/moby,jlhawn/docker,crosbymichael/docker,moby/moby,rancher/docker,x1022as/docker,konstruktoid/docker-1,justincormack/docker,johnstep/moby-moby,rancher/docker,johnstep/moby-moby,crosbymichael/docker,ibuildthecloud/docker,nalind/docker,gnailuy/docker,kojiromike/docker,estesp/docker,KarthikNayak/docker,mahak/docker,allencloud/docker,AkihiroSuda/docker,kolyshkin/docker,konstruktoid/docker-upstream,AkihiroSuda/docker,ibuildthecloud/docker,scotttlin/docker,cpuguy83/docker,jlhawn/docker,docker/docker,unclejack/docker,allencloud/docker,moul/docker,pradipd/moby,rremer/moby,laijs/docker,tmp6154/docker,AkihiroSuda/docker,moul/docker,kolyshkin/moby,bearstech/moby,estesp/docker,jwhonce/docker,flavio/docker,rremer/moby,maxamillion/docker,scotttlin/docker,estesp/docker,thaJeztah/docker,jthelin/docker,flavio/docker,YuPengZTE/docker,tmp6154/docker,mahak/docker,jwhonce/docker,Mokolea/docker,kolyshkin/docker,nawawi/docker,yosifkit/docker,Mokolea/docker,Ramzec/docker,yongtang/docker,djs55/docker,rancher/docker,djs55/docker,dmcgowan/docker,jimjag/docker,moul/docker,mahak/docker,SvenDowideit/docker,trebonian/docker,KarthikNayak/docker,Ramzec/docker,yosifkit/docker,nawawi/docker,laijs/moby,crosbymichael/docker,thaJeztah/docker,dims/docker,jameszhan/docker,djs55/docker,SvenDowideit/docker,jimjag/docker,moby/moby,mikebrow/docker,jlhawn/docker,jameszhan/docker,vdemeester/docker,jameszhan/docker,paralin/docker,trebonian/docker,x1022as/docker,jvanz/docker,mikebrow/docker,pradipd/moby,bearstech/moby,konstruktoid/docker-upstream,gnailuy/docker,cpuguy83/docker,nawawi/docker,jvanz/docker,yongtang/docker,jimjag/docker,docker/docker,jimjag/docker,justincormack/docker,Mokolea/docker,konstruktoid/docker-1,ibuildthecloud/docker,paralin/docker,johnstep/moby-moby,kolyshkin/moby,moul/docker,trebonian/docker,pradipd/moby,nalind/docker,AkihiroSuda/docker,yosifkit/docker,laijs/moby,nalind/docker,scotttlin/docker,justincormack/docker,vdemeester/docker,moby/moby,docker/docker,flavio/docker,unclejack/docker,x1022as/docker,YuPengZTE/docker,thaJeztah/docker,bearstech/moby,thaJeztah/docker,nalind/docker,bearstech/moby,yosifkit/docker,jvanz/docker,laijs/docker,dmcgowan/docker,vdemeester/docker,nawawi/docker,cpuguy83/docker,tmp6154/docker