IPv6 Reassemble Error for Fragmented Packets

Issue

• IPv6 Reassemble Error for Fragmented SNMP Packets
• Any IPv6 fragmented payload where the More Fragments (MF) flag is set to 1 (i.e. not the last fragment) and the IPv6 Header Payload Length is less than 1240 bytes (short fragment) regardless of the upper layer protocol will trigger an ICMPv6 type 4 (Parameter Problem) response.
• IPv6 Conformance Test v6LC.1.3.1/v6LC.1.3.2 fails on RHEL 8.0 and earlier
• When receiving some fragmented IPv6 traffic, RHEL replies in tcpdump with:

ICMP6, parameter problem, erroneous - octet 40, length 1240

• RHEL returns ICMPv6 packet with:
  • Type: Parameter Problem (4)
  • Code: 0 (erroneous header field)
  • Pointer: 40 (start of Fragment Header)