This blog article records the progress of setting up IPv6 tunnel to Hurricane Electric at home where my ISP has no plan in sight to provide prefix-delegated IPv6 access over a PPPoE.
Shorthands and Assumptions in This Note
eth0connects to the Internet via IPv4. This note shall also apply to encapsulated interfaces, e.g.
eth1connects to local LAN. Similar as above, the process shall be the same when LAN side is a VLAN or bridge (or both).
sittunnel interface created in this step.
- A line beginning with
#denotes comments in the configuration notes.
Setting up the Tunnel Interface on ER-X
If registered correctly on TunnelBroker, it should provide the following information:
- Logical address at local endpoint, e.g.
- Logical address at remote endpoint, e.g.
- IPv4 address at remote endpoint where encapsulated traffic is sent, e.g.
188.8.131.52, the HE tunneling endpoint in Paris.
- A routable prefix for client side delegation, e.g.
2001:444:112:222::/64. This is usually different from the v6 addresses for the endpoint, and HE will show segments of the prefix in bold.
Now fill ER-X configuration nodes with corresponding information and default routing for IPv6:
interfaces: tunnel: tun0: address: [Fill logical v6 address in CIDR at endpoint] description: [Give a name to this tun] encapsulation: sit local-ip: [Fill in IPv4 address at eth0] remote-ip: [Fill in IPv4 address at tunneling endpoint] protocols: static: interface-route6: ::/0: next-hop-interface: tun0 # This creates a default IPv6 routing table entry that # routes all non-link-local address to the tunnel.
At this point, one should be able to ping any IPv6 address from the ER-X. If this is working, continue to instruct the LAN interface to delegate the prefix
interface: <path-to-interface-config-node>: ipv6: dup-addr-detect-transmits: 1 # Stateless SLAAC configuration might produce identical # IP addresses. This allow the network to detect whether # a stateless address already exists. address: autoconf # Set autoconf to allow stateless delegation by SLAAC router-advert: prefix: [Fill routable delegated prefix here]: autonomous-flag: true # Instructs computers on this network to auto # discover DNS servers on-link-flag: true # Indicates that this prefix exists on the # same Ethernet link, i.e. these addresses # does not require routing
IPv6 enabled devices shall now receive globally unique IPv6 address assigned via SLAAC and prefix delegation.
- Confirm IPv6 assignment on LAN devices
$ ip addr <------ MORE INTERFACES REDACTED ------> 2: eno1: mtu 1480 qdisc fq_codel state UP group default qlen 1000 link/ether XX:XX:XX:XX:XX:XX brd ff:ff:ff:ff:ff:ff inet 192.168.5.4/24 brd 192.168.5.255 scope global dynamic noprefixroute eno1 valid_lft 80444sec preferred_lft 80444sec inet6 2001:470:d:XXXX:XXXX:XXXX:XXXX:dfd3/64 scope global dynamic noprefixroute valid_lft 2591976sec preferred_lft 86376sec inet6 fe80::be40:XXXX:XXXX:XXXX/64 scope link noprefixroute valid_lft forever preferred_lft forever <------ MORE INTERFACES REDACTED ------>
- Trace IPv6 connections to an IPv6 enabled website
$ traceroute -6 ac.cth451.me -n traceroute to ac.cth451.me (2606:4700:30::681c:1b16), 30 hops max, 80 byte packets 1 2001:470:d:XXXX:XXXX:XXXX:XXXX:XXXX 0.415 ms 0.533 ms 0.624 ms 2 2001:470:c:XXXX::1 185.353 ms * 203.802 ms 3 2001:470:0:9d::1 178.603 ms 167.001 ms 189.255 ms 4 2001:504:0:3:0:1:3335:1 196.520 ms 179.737 ms 196.117 ms 5 2400:cb00:12:1024::6ca2:d61d 185.036 ms 2400:cb00:12:1024::6ca2:d614 175.573 ms 2400:cb00:12:1024::6ca2:d608 185.263 ms
- It is advisable to setup network wide firewall on the router, as addresses can be reached by any other IPv6 connected devices from the Internet.
sittunnel shall also work if setup correctly on any other router or even a personal computer with public IPv4 address. I am unable to replicate the settings on a Linux router via raw commands as I do not own a linux machine with public IPv4 address.
- I am not sure if the method would work if the local endpoint is behind NAT. This scenario will be experimented on after I return to campus.