IPv6 startup script
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[[Category:IPv6]] | [[Category:IPv6]] | ||
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Revision as of 13:51, 23 October 2010
Instructions
Use this script once you have been assigned a SixXS tunnel to connect that tunnel. Once your tunnel has been up for a week, you earn enough credits to request a subnet (/48 IPv6 allocation) which you can then use for hosts on your network. See the instructions in the SETUP VALUES section for more info.
See http://www.sixxs.net/main/ for info on how to request tunnels and subnets.
Any feedback on the script welcome in this forum topic.
#!/bin/sh # # SIXXS IPv6 startup script for WRT54G # From http://www.dd-wrt.com/wiki/index.php/IPv6_startup_script ################################## ### SETUP VALUES ### ### Change these before running ## ################################## # The IPv6 prefix (/64) of the tunnel initially assigned to you by SixXS (including the ::). # Only the ::1 and ::2 are used from this range, for the PoP and your router, respectively. # You need to keep the tunnel up for a week in order earn enough credits to request a /48 subnet # (see below) which can then be used by hosts on your network. TUNNELPREFIX="2001:db8:1111:1111::" # The IPv4 address of the SixXS PoP you're using SIXXS4="1.1.1.1" # MTU - must match your SixXS tunnel settings and radvd's "AdvLinkMTU" value; 1280 is the default but it can be increased. # This script will give you a recommendation when you run it, but it should be 20 less than your IPv4 MTU. MTU=1280 # A /64 from your /48 subnet prefix assigned by SixXS, INCLUDING the /64 ## This should match what you announce to the network with radvd (set in Administration -> Management in the web interface) # If you have not yet been assigned this (you need to keep the tunnel up for a week to earn enough credits), leave blank/commented out ##SUBNET="2001:db8:2222::/64" # Space-separated list of extra IPs you want for your router, such as: # * Local (RFC 4193, currently draft) address e.g. fdxx:xxxx:xxxx:yyyy::1/64; or # * site-local (as per RFC 1918, but obseleted by RFC 3879) address e.g. fec0::1/64 # * Any other local or global fixed address you want (note: we already assign the above SUBNET address) # This is optional, leave blank/commented out if not wanted. ###ADDITIONALIP6="fec0::1/64" ################################## ### END OF SETUP VALUES ## ################################## logger -st sixxs -- "Starting IPv6 setup" # Get the tunnel endpoint addresses MYTUNNELIP="${TUNNELPREFIX}2" SIXXSTUNNELIP="${TUNNELPREFIX}1" # Get our external IPv4 (in case the IP isn't available, because we don't have a connection yet, retry 3 times or until we succeed) RETRIES=3 while [ -z ${EXTIP} ]; do # PPPoE devices are on ppp0, all others are on vlan1 or eth1; we try all for DEV in "ppp0" "vlan1" "eth1"; do EXTIP=`/usr/sbin/ip -4 addr show dev ${DEV} | grep inet | awk '{print $2}' | cut -d/ -f1` if [ -n "$EXTIP" ]; then logger -st sixxs -- "- External IP ${EXTIP} found on device ${DEV}" break 2 fi done let RETRIES-=1 if [ "$RETRIES" -gt 0 ]; then logger -st sixxs -- "- No external IP found; trying again in 10 secs..." sleep 10 else logger -st sixxs -- "- No external IP found after 30 seconds; quitting" exit 1 fi done # Create tunnel logger -st sixxs -- "- Creating SixXS tunnel ${EXTIP} <--> ${SIXXS4}" /usr/sbin/ip tunnel add sixxs mode sit local ${EXTIP} remote ${SIXXS4} # Bring tunnel interface up explicitly logger -st sixxs -- "- Bringing sixxs device up" /usr/sbin/ip link set sixxs up # Fix MTU and TTL logger -st sixxs -- "- Fixing MTU and TTL of sixxs device" /usr/sbin/ip link set mtu ${MTU} dev sixxs /usr/sbin/ip tunnel change sixxs ttl 64 # Check for optimal MTU # Max MTU is device's MTU minus 20 (IPv6 headers are 20 bytes bigger than IPv4) RECMTU=`ip addr show dev $DEV | grep mtu | awk '{print $5}'` RECMTU=`expr ${RECMTU} - 20` if [ ${MTU} -lt ${RECMTU} ]; then logger -st sixxs -- "- Note: You could increase your MTU setting from ${MTU} to ${RECMTU} for improved performance. Change it in ${0}, radvd.conf and in the SixXS tunnel config." elif [ ${MTU} -gt ${RECMTU} ]; then ### TODO: What happens if MTU is too high? logger -st sixxs -- "- WARNING: Your MTU ${MTU} is too high - it should be ${RECMTU}. Change it in ${0}, radvd.conf and in the SixXS tunnel config." fi # Add extra IPs if any if [ ! -z ${ADDITIONALIP6} ]; then for IP in ${ADDITIONALIP6}; do logger -st sixxs -- "- Adding fixed IP ${IP}" /usr/sbin/ip -6 addr add ${IP} dev br0 done fi # Configure IPv6 endpoint on the tunnel logger -st sixxs -- "- Configuring local IPv6 tunnel endpoint ${MYTUNNELIP}" /usr/sbin/ip -6 addr add ${MYTUNNELIP}/64 dev sixxs # Add default route logger -st sixxs -- "- Adding default route through SixXS ${SIXXSTUNNELIP}" /usr/sbin/ip -6 ro add default via ${SIXXSTUNNELIP} dev sixxs if [ ! -z ${SUBNET} ]; then # Add a network from the /48 subnet to br0 logger -st sixxs -- "- Setting up subnet ${SUBNET}" /usr/sbin/ip -6 addr add ${SUBNET} dev br0 ## # Start router advertisement daemon ## # No need to do this here; just use the setup in the web interface ## logger -st sixxs -- "- Starting radvd..." ## /usr/sbin/radvd -C /tmp/radvd.conf else logger -st sixxs -- "- Note: No subnet configured yet - apply for one when you've kept the tunnel up for a week and earned enough credits" fi logger -st sixxs -- "SixXS IPv6 setup done"
radvd configuration
An example radvd.conf, to be used once you have been assigned a /48 subnet (see Administration -> Management in your router's web interface):
interface br0 { AdvSendAdvert on; AdvHomeAgentFlag on; AdvLinkMTU 1280; MinRtrAdvInterval 3; MaxRtrAdvInterval 10; prefix [REPLACE WITH SUBNET]/64 { AdvOnLink on; AdvAutonomous on; AdvRouterAddr on; }; };