I have noticed during port scanning that my "anonymous" IP has an open port (111) while I am using VPN.

Does this make me vulnerable as user or is it the provider's failure? Should I change providers or do I have nothing to worry about (since, if the providers' network security is compromised, mine is in risk as well)?

2 Answers 2


NOTE: All of this assumes you are talking about TCP 111 (vs UDP).

If you are using a VPN service, you are sharing that Public IP with many customers and being NAT'd somewhere along the way. This Public IP is generally not directly routable to you as a user of the service, as such, there isn't much to worry about.

That being said, it's hard to know (without more info/probing) exactly what is running on that open port. In general, ports 1-1023 fall in the Well-Known Ports range, though that's not to say that something else can't be running on this port, but it's likely an RPC (remote procedure call) service like SunRPC.

TL; DR You're probably fine, but if you're still worried about, contact the VPN vendor and ask them exactly what it is and what it's used for.


The port might be consumed by rpcbind. What rpcbind does, is described here

An excerpt:

When a client signs up for a given interface on a particular host, usually with a clnt_create() call, the stub code asks rpcbind on that host a question, something like "on what UDP or TCP port is protocol number X listening?" rpcbind, unlike most other ONC services, listens on TCP and UDP port 111, so given a host name or IP address, a program can just ask rpcbind on that host or IP address. rpcbind responds with the appropriate port number, if a server has registered with it on that host. That registration is done by the server process when it calls svc_create().

  • This will give you your TCP/UDP 111, the OP asked about the IP address he's presenting as.
    – HashHazard
    Jul 15, 2016 at 21:35
  • fair. modified the answer to be more specific
    – sandyp
    Jul 15, 2016 at 21:49

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