Add `IPV6_V6ONLY` IPV6 socket option

SO says this is required for proper UDP socket multi-homing.

2 files changed, 3 insertions, 2 deletions

diff --git a/pysnmp/carrier/asyncore/dgram/base.py b/pysnmp/carrier/asyncore/dgram/base.py
index 4edae19b..d38f3080 100644
--- a/pysnmp/carrier/asyncore/dgram/base.py
+++ b/pysnmp/carrier/asyncore/dgram/base.py
@@ -78,6 +78,7 @@ class DgramSocketTransport(AbstractSocketTransport):
 
             if self.socket.family == socket.AF_INET6:
                 self.socket.setsockopt(socket.SOL_IPV6, socket.IPV6_RECVPKTINFO, flag)
+                self.socket.setsockopt(socket.SOL_IPV6, socket.IPV6_V6ONLY, not flag)
 
         except socket.error:
             raise error.CarrierError('setsockopt() for %s failed: %s' % (self.socket.family == socket.AF_INET6 and "IPV6_RECVPKTINFO" or "IP_PKTINFO", sys.exc_info()[1]))
diff --git a/pysnmp/carrier/sockmsg.py b/pysnmp/carrier/sockmsg.py
index 0b21233b..97273306 100644
--- a/pysnmp/carrier/sockmsg.py
+++ b/pysnmp/carrier/sockmsg.py
@@ -92,7 +92,7 @@ else:
 
             debug.logger & debug.flagIO and debug.logger(
                 'recvfrom: received %d octets from %s to %s; '
-                'iov blob %r' % (len(data), _from, _to, ancdata))
+                'iov blob %s' % (len(data), _from, _to, debug.hexdump(ancdata)))
 
             return data, addressType(_from).setLocalAddress(_to)
 
@@ -120,7 +120,7 @@ else:
                 ancdata = [(socket.SOL_IPV6, socket.IPV6_PKTINFO, memoryview(_f).tobytes())]
 
             debug.logger & debug.flagIO and debug.logger(
-                'sendto: sending %d octets to %s; iov blob %r' % (len(data), _to, ancdata))
+                'sendto: sending %d octets to %s; iov blob %s' % (len(data), _to, debug.hexdump(ancdata)))
 
             return s.sendmsg([_data], ancdata, 0, _to)