The World is running out of IPv4 addresses, but luckily, we have IPv6 here now, and running the whole data center on IPv6 only is not just happening, it’s becoming the standard. But what if you have an app, a daemon, or a container that actually needs IPv4 connectivity? Then you may use 464XLAT to provide an IPv4 tunnel through your IPv6 only infrastructure. clatd is one component in 464XLAT.

clatd is a CLAT / SIIT-DC Edge Relay implementation for Linux. From the github wash label:

clatd implements the CLAT component of the 464XLAT network architecture specified in RFC 6877. It allows an IPv6-only host to have IPv4 connectivity that is translated to IPv6 before being routed to an upstream PLAT (which is typically a Stateful NAT64 operated by the ISP) and there translated back to IPv4 before being routed to the IPv4 internet. This is especially useful when local applications on the host requires actual IPv4 connectivity or cannot make use of DNS64 (…) clatd may also be used to implement an SIIT-DC Edge Relay as described in RFC 7756.

Note that clatd relies on Tayga for the actual translation of packets between IPv4 and IPv6.

Yesterday, I pushed clatd for Fedora testing and EPEL testing. Please test and report feedback by bugzilla.

For more information on clatd, see the documentation included in the package, or the clatd github home page. For more info on Tayga, visit

For general information about the process of transisioning to the britght future of IPv6, consider

Ingvar Hagelund

Team Lead, Application Management for Media at Redpill Linpro

Ingvar has been a system administrator at Redpill Linpro for more than 15 years. He's also a long time contributor to the Fedora and EPEL projects.

Layer 3 routing on Cumulus Linux MLAG

We build our network in order to simultaneously achieve high availability and maximum utilisation of available bandwidth. To that end, we are using Multi-Chassis Link Aggregation (MLAG) between our data centre switches running Cumulus Linux and our firewall cluster «on a stick»:

MLAG topology

fw1 is tricked into believing it is dual connected to a single device that speaks the IEEE 802.3ad Link Aggregation Control Protocol. This works great for layer 2 and ... [continue reading]

Mule 4 SDK custom connector example

Published on February 02, 2018

Jenkinsfile to Anypoint platform and Artifactory

Published on January 26, 2018