IPv6 Network - pTRTd on Linux Because the LinuxIPv6 stack doesn’t have any KAME ancestry, it doesn’t have faith. However, for Linux, there is the Portable Transport Relay Translator Daemon (pTRTd),3 which is even better. pTRTd supports UDP, doesn’t clash with local services, and a single daemon handles all ports. pTRTd is available at http://www.litech.org/ptrtd/ and is installed using the customary ./configure, make, make install sequence. pTRTd depends the ip package (see Chapter 3) and the tuntap network driver. Both are included in the Red Hat 9 distribution. If started without arguments, the ptrtd daemon will use site local fec0:0:0:ffff::/96 prefix as the magic TRT prefix. Because pTRTd doesn’t include any access restrictions, it would be a good idea to have the TRT prefix in site local space. Unfortunately, this doesn’t work: the system keeps complaining that it “cannot assign” addresses. Specifying a prefix in global unicast space with (for instance) ptrtd -p 2001:db8:31:6464:: works much better. To make sure that others won’t abuse the relay, it’s important to set up firewall rules or a router access list to limit access to the relay.
Caution: I was unable to use pTRTd to connect from other IPv6 hosts to the IPv4 Internet on Red Hat ES4 Linux, even though the Red Hat machine itself was capable of going through pTRTd. But because this hostmust be dual stack anyway, that doesn’t do much good.
