We need to adapt all functional traffic scripts related to functional IPv6 tests to ingore receiving of unexpected ICMPv6 Neighbor Discovery - Neighbor Solicitation packets that are sent automatically and we cannot avoid to receive them.

The reason is to prevent false negative test results in case of csit functional tests that could block creation of new operational branch (csit weekly jobs), usage of new vpp builds (csit semiweekly jobs) and merging patches - csit as well as vpp.

Propsed solution:

while True:
        # receive ICMPv6 echo reply
        ether = rxq.recv(2, sent_packets)
        if ether is None:
            raise RuntimeError('ICMPv6 echo reply Rx timeout')

        if ether.haslayer(ICMPv6ND_NS):
            # read another packet in the queue if the current one is ICMPv6ND_NS
            continue
        else:
            # otherwise process the current packet
            break