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Help with public networking (instance) communication issue

asked 2016-05-04 13:52:55 -0500

johnnwvs gravatar image

I have been working on this for a few days now, and it seems like it is time to ask for help.

I set up a new Mirantis 8 install, with four NICs. The hosts themselves can all communicate with the outside world, at least via a quick "ping (") test. The cirros instances that I launch can ping each other, which is great.

The issue is that I cannot ping to something like from an instance, as I can on the hosts. I was able to attach a floating IP, and an additional interface - attached to a subnet on my public subnet (172.16.0.x/24). I can ping the router's IP ( from my instance and from my router I can ping the IP of my cirros VM ( from within my host via the following command:

ip netns exec qdhcp-long-id-name-here ping

But when I attempt to ping from the host in a similar manner, I cannot:

ip netns exec dqhcp-long-id-name-here ping From icmp_seq=1 Destination Host Unreachable

I also tried doing a host lookup and substituting an IP address to ping, no luck.

Extra info: ip netns exec dqhcp-long-id-name-here ip a | grep 172

inet ...

Any idea what I should try next?

John Jones

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answered 2016-05-04 23:38:02 -0500

fxpester gravatar image

1) try to ping
2) if failed run - tcpdump -an eth0 icmp on the network node(or host node if they same) and post output here - it looks like nat problem.
3) your installation is on hardware or inside vmware ?

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Asked: 2016-05-04 13:52:55 -0500

Seen: 168 times

Last updated: May 04 '16