# Mobility-Multihoming Duality
## 5 Evaluation of Mobility Multihoming Duality
### Testbed Hardware, Network Topology, and Configuration  
The testbed consisted of the following:  
* A total of 4\(\times\) commercial IPv6 routers, R1-R4, that were unmodified with respect to ILNP. * A total of 2\(\times\) host nodes, for an MN and CN, consisting of a low-end server motherboard, where this server motherboard was chosen because it had 4\(\times\) ethernet interfaces onboard for convenience. * The ILNP kernel was modified from [50] with some additional control features: 1. A system parameter, net.ilnp6.handoff_mode, which can be set using an sysctl call to invoke the ILNP behaviour for the host. 2. A system parameter, net.ilnp6.disabled_interface which holds a list of interfaces that is disabled (not in use). 3. When multiple L64 values, and therefore multiple networks, are in use, a Deficit Round-Robin (DRR) mechanism [51] was used to share packets between the networks. \begin{table}
\begin{tabular}{c c} \hline \hline
**Option** & **Explanation** \\ \hline gso off & turn off generic segmentation offload \\ gso off & turn off generic segmentation receive \\ tso off & turn off TCP segmentation offload \\ rx off & turn off TCP receive check sum \\ tx off & turn off TCP transmission check sum \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Interface configuration options for ethtool(8) to avoid incorrect ILNP processing in NIC hardware. These were executed for each interface/NIC. \begin{table}
\begin{tabular}{l l} \hline \hline
**Parameter** & **Explanation** \\ \hline router\_solicitation\_delay = 0 & delay before generation of RS when an interface is enabled \\ router\_solicitation\_interval = 1 & delay interval between periodic RS messages \\ optimistic\_dad = 1 & enable use of optimistic DAD, i.e., ‘optimistic’ addresses \\ use\_optimistic = 1 & always use (do not deprecate) optimistic addresses \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The parameters configured using sysctl(8), to be applied for each interface, using the net.ipv6.conf._interface_ prefix to enable timely generation of IPv6 RA and RS messages. This was executed for each _interface_/NIC. DAD is Duplicate Address Detection, part of IPv6 address management, and not specific to ILNP. * For a node, the route selection mechanism for the IPv6 was updated, removing the assumption of the use of a single network. This is described in Section 4.5 and discussed further in Section 7.1. The details of the system are given in Table 4. The connectivity of the testbed was as shown in Figure 6. There were four IPv6 routers, R1-R4, providing access to four IPv6 networks that are listed in Table 5, which we will for convenience call networks aa-dd. R1, R2, and R3 provided access networks for the MN. The configuration of the IPv6 RAs for these routers is as given in Table 6. The glibc C library was modified to hold IL-V values in the /etc/hosts file to avoid DNS latency and for experimental convenience. Specifically, the glibc was modified to parse the custom IL-V syntax as shown below: n-n-n-n.l+l+l+l hostname The n-n-n-n value is the NID, which is of a similar format to the unicast IPv6 IID, where \":\" was replaced with \"-\". The l+l+l+l value is the L64 value, the unicast IPv6 routing prefix, where \":\" was replaced with \"+\". This provided a fixed IL-V used to initialise ILNP communication, after which the movement and multihoming occurred. Below is an example of an IL-V entry: d250-99 ff-fed1-5a0c.2001+2+dd+dd mm-ddd-ilnp \begin{table}
\begin{tabular}{l c c} \hline \hline  & **Equipment/Software** & **Additional Information** \\ \hline R1, R2, R3 & Ubiquitin Network ER-X1  \\ \hline R4 & Ubiquitin Network ER-6P  \\ \hline MN/CN & Motherboard & Intel Atom C3558 (4-core) SoC \\  & ASRock C3558 DI4-4L  \\ \hline  & Operating System & Debian 9.7 with Linux kernel v4.9 ILNP \\ \hline  & Traffic generation & iperf2 v2.0.9 \\ \hline  & Packet Capture & tcpdump v4.9.3 with libpcap v1.8.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Testbed equipment information.