3 DatagramChannel tests and 2 MulticastSocket tests fail due to "SocketException: No buffer space available"
The following three NIO tests and 2 NET tests are failing in the JDK15 CI:

java/nio/channels/DatagramChannel/Promiscuous.java
java/nio/channels/DatagramChannel/MulticastSendReceiveTests.java
java/nio/channels/DatagramChannel/AdaptorMulticasting.java
java/net/MulticastSocket/SetOutgoingIf.java
java/net/MulticastSocket/SetLoopbackModeIPv4.java

Here's a snippet from the log file for Promiscuous.java:

----------System.err:(18/1121)----------
java.net.SocketException: No buffer space available
at java.base/sun.nio.ch.DatagramChannelImpl.send0(Native Method)
at java.base/sun.nio.ch.DatagramChannelImpl.sendFromNativeBuffer(DatagramChannelImpl.java:894)
at java.base/sun.nio.ch.DatagramChannelImpl.send(DatagramChannelImpl.java:871)
at java.base/sun.nio.ch.DatagramChannelImpl.send(DatagramChannelImpl.java:814)
at Promiscuous.sendDatagram(Promiscuous.java:75)
at Promiscuous.test(Promiscuous.java:179)
at Promiscuous.main(Promiscuous.java:223)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:298)
at java.base/java.lang.Thread.run(Thread.java:832)

JavaTest Message: Test threw exception: java.net.SocketException
JavaTest Message: shutting down test

----------System.out:(5/138)----------

Test family=INET
dc1 joining [225.4.5.6]:52094 @ en1
dc2 joining [225.4.6.6]:52094 @ en1
Send message -> group 225.4.5.6 (id=0x1c050393)
result: Failed. Execution failed: `main' threw exception: java.net.SocketException: No buffer space available


test result: Failed. Execution failed: `main' threw exception: java.net.SocketException: No buffer space available


Starting this as a P3 since these are Tier2 test failures.