RFC Errata
RFC 4890, "Recommendations for Filtering ICMPv6 Messages in Firewalls", May 2007
Source of RFC: v6ops (ops)See Also: RFC 4890 w/ inline errata
Errata ID: 3985
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: James Robertson
Date Reported: 2014-05-13
Verifier Name: Joel Jaeggli
Date Verified: 2014-05-19
Section Appendix B says:
if [ "$STATE_ENABLED" -eq "1" ] then # Allow incoming time exceeded code 0 messages # only for existing sessions for inner_prefix in $INNER_PREFIXES do ip6tables -A icmpv6-filter -m state -p icmpv6 \ -d $inner_prefix \ --state ESTABLISHED,RELATED --icmpv6-type packet-too-big \ -j ACCEPT done else # Allow incoming time exceeded code 0 messages for inner_prefix in $INNER_PREFIXES do ip6tables -A icmpv6-filter -p icmpv6 -d $inner_prefix \ --icmpv6-type ttl-zero-during-transit -j ACCEPT done fi
It should say:
if [ "$STATE_ENABLED" -eq "1" ] then # Allow incoming time exceeded code 0 messages # only for existing sessions for inner_prefix in $INNER_PREFIXES do ip6tables -A icmpv6-filter -m state -p icmpv6 \ -d $inner_prefix \ --state ESTABLISHED,RELATED --icmpv6-type ttl-zero-during-transit \ -j ACCEPT done else # Allow incoming time exceeded code 0 messages for inner_prefix in $INNER_PREFIXES do ip6tables -A icmpv6-filter -p icmpv6 -d $inner_prefix \ --icmpv6-type ttl-zero-during-transit -j ACCEPT done fi
Notes:
RFC 4890 Errata ID 2706 states that icmpv6-type packet-too-big should
state icmpv6-type ttl-zero-during-transmit. This should read
ttl-zero-during-transit.