Problem on channel.OpenAsync() when using IP address

[hclf99]

I see a strange behavior on connection to my server: When using the IP address e.g. opc.tcp://xxx.xxx.xxx.xxx:4840 sometimes I get connected sometimes not (randomly), but instead when I use the PC Network name e.g. opc.tcp://MYDEFPC:4840 it always connects without problems.
Using:
channel = new ClientSessionChannel
(
clientDescription,
// no x509 certificates
null,
// no user identity
new AnonymousIdentity(),
// the OPC server
server, ===> using addressee as described above
// no encryption
SecurityPolicyUris.None
);
Using version 3.2.3 on NET 4.8

By the way: The older version of my application used "channel = new UaTcpSessionChannel" without problems for both addressing methods

[awcullen]

Thanks for the bug report. Could you share the exception you get when the client can't connect?

[hclf99]

Unfortunately there is no exception occurring, the connection attempt simple times out.... for example if I use this:
Task t = channel.OpenAsync();
t.Wait(10000);
...

after 10 sec it still says: CommunicationState.Opening and it stays forever in the opening state

I tried different OPC-UA servers for connection tests, on some it works without any problem on some (e.g Siemens S7) not (timeout)