I describe a little bit how to secure your IPv6 server with Netfilter-ip6tables.
Refer to the IANA message types.
My example IPv6 firewall script:
Earlier predefined variables:
1 2 | IPT6="/sbin/ip6tables" OUTER="eth0" |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 | # Clean old IPv6 firewall $IPT6 -F $IPT6 -X # Clean old iptables v6 tables for chain in mangle filter do $IPT6 -t $chain -F $IPT6 -t $chain -X done # Set IPv6 default chains $IPT6 -P INPUT DROP $IPT6 -P FORWARD DROP $IPT6 -P OUTPUT ACCEPT $IPT6 -A INPUT -i $OUTER -m state --state RELATED,ESTABLISHED -j ACCEPT $IPT6 -A INPUT -i lo -j ACCEPT # Allow SSH from Hetzner IPv6-NET $IPT6 -A INPUT -s 2001:470:1f0b:1604::/64 -i $OUTER -p tcp -m tcp --dport 22 -j ACCEPT # Allow SSH from Home IPv6-NET $IPT6 -A INPUT -s 2001:470:1f0b:1514::/64 -i $OUTER -p tcp -m tcp --dport 22 -j ACCEPT # Allow ICMP from Hetzner IPv6-NET $IPT6 -A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 128 -m limit --limit 15/sec -s 2001:470:1f0b:1604::/64 -j ACCEPT $IPT6 -A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 129 -m limit --limit 15/sec -s 2001:470:1f0b:1604::/64 -j ACCEPT # Allow ICMP from Home IPv6-NET $IPT6 -A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 128 -m limit --limit 15/sec -s 2001:470:1f0b:1514::/64 -j ACCEPT $IPT6 -A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 129 -m limit --limit 15/sec -s 2001:470:1f0b:1514::/64 -j ACCEPT $IPT6 -A INPUT -i $OUTER -p tcp -m tcp --dport 25 -j ACCEPT # SMTP $IPT6 -A INPUT -i $OUTER -p tcp -m tcp --dport 53 -j ACCEPT # DNS via TCP $IPT6 -A INPUT -i $OUTER -p udp -m udp --dport 53 -j ACCEPT # DNS via UDP $IPT6 -A INPUT -i $OUTER -p tcp -m tcp --dport 80 -j ACCEPT # HTTP $IPT6 -A INPUT -i $OUTER -p tcp -m tcp --dport 110 -j ACCEPT # POP3 $IPT6 -A INPUT -i $OUTER -p tcp -m tcp --dport 143 -j ACCEPT # IMAP $IPT6 -A INPUT -i $OUTER -p tcp -m tcp -s 2001:470:1f0b:1604::3/64 --dport 4949 -j ACCEPT $IPT6 -A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 133 -m hl --hl-eq 255 -j ACCEPT $IPT6 -A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 134 -m hl --hl-eq 255 -j ACCEPT $IPT6 -A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 135 -m hl --hl-eq 255 -j ACCEPT $IPT6 -A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 136 -m hl --hl-eq 255 -j ACCEPT $IPT6 -A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 137 -m hl --hl-eq 255 -j ACCEPT $IPT6 -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT # Example of logging $IPT6 -A INPUT -p ipv6-icmp -j LOG --log-prefix "Dropped ICMPv6 Packets " |
