Question

Isolating network from other droplets

  • Posted on March 7, 2013
  • adfAsked by adf

I see lots of ARP and UDP activity from other hosts on the same network as my droplet, despite not obviously allowing those in iptables (though I allow RELATED and ESTABLISHED)

Is there a way to isolate my doplet from the rest of the subnet without affecting its internet access?


Submit an answer

This textbox defaults to using Markdown to format your answer.

You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!

Sign In or Sign Up to Answer

These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.

Want to learn more? Join the DigitalOcean Community!

Join our DigitalOcean community of over a million developers for free! Get help and share knowledge in Q&A, subscribe to topics of interest, and get courses and tools that will help you grow as a developer and scale your project or business.

This is a problem guys… why are you okay with being able to browse all network traffic on the same segment, even if the destination is not localhost? <br> <br>Are the droplets connected via hub? How have you misconfigured the VSwitch? This is a big privacy issue even for those that do ssl-everywhere…

We would need to review your iptables rules to see what traffic you are blocking and how, if you like and you are not talking to any other virtual servers you can just drop all traffic from other hosts on the network and only allow your own droplets to communicate with each other.

Example of traffic seen <br> <br>root@locutus:/var/log# tcpdump src net 192.81.223/24 and dst net 192.81.223/24 <br>tcpdump: verbose output suppressed, use -v or -vv for full protocol decode <br>listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes <br>10:15:16.557076 ARP, Request who-has ubuntunorge.com tell 192.81.223.2, length 46 <br>10:15:17.854127 ARP, Request who-has 192.81.223.1 tell 192.81.223.1, length 46 <br>10:15:18.753579 IP 192.81.223.118.17500 > 192.81.223.255.17500: UDP, length 123 <br>10:15:19.853784 ARP, Request who-has 192.81.223.1 tell 192.81.223.1, length 46 <br>10:15:21.853997 ARP, Request who-has 192.81.223.1 tell 192.81.223.1, length 46 <br>10:15:22.072348 ARP, Request who-has synth.pl tell 192.81.223.3, length 46 <br>10:15:22.555656 ARP, Request who-has 192.81.223.28 tell 192.81.223.2, length 46 <br> <br>10:16:53.186513 IP do1.maykastudio.ru.17500 > 192.81.223.255.17500: UDP, length 112 <br> <br>10:17:13.011074 ARP, Request who-has 192.81.223.51 tell 192.81.223.3, length 46 <br>10:17:13.011116 ARP, Reply 192.81.223.51 is-at 04:01:01:97:7d:01 (oui Unknown), length 28 <br> <br>So thats ARP requests from .1 .2 and .3 hosts (only those) and some other hosts doing UDP broadcasts