Scyphus Draft

This site ( provides draft technical documents about computers and networking and our open source softwares. Consequently, the documents/softwares in this site are frequently changing, and pages might be moved to another permanent site with announcements or notifications, though we do not plan to do it.

Use the information and softwares provided on this site on your own responsibility. If you find any errors, please let us know via E-mail <bug __at__> (please replace "__at__" with "@"). The support team speaks both English and Japanese.

We note that this site is managed by Scyphus Solutions Co. Ltd. in Japan. Our twitter(TM) account is "@scysol".

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Programming Language



IPv6 ready Web sites

We crawled Web sites over the Internet. The list of IPv6 ready Web sites is available at IPv6 ready Web sites.

6to4 on FreeBSD (written in Japanese)

Please refer to 6to4 on FreeBSD (in Japanese).

Mac OS X tips

Please refer to Mac OS X tips.



Please refer to HTML5 memo (in Japanese).

Cisco Aironet Series

Firmware upgrade

Please refer to Firmware upgrade in Cisco Aironet series.


VMware ESX/ESXi CLI Tips

Please refer to VMware ESX/ESXi CLI Tips.

Upgrading VMware ESXi

Please refer to Upgrading VMware ESXi via CLI.


Package audit

Please refer to Package audit on *BSD/Linux.

NAT with FreeBSD

Please refer to FreeBSD as NAT gateway.

Discovering path MTU with ping command

To discover path MTU, you perhaps use ping command with the “Don't Fragment bit”. “Don't Fragment bit” can be set by a command line option of ping, but the option is different between BSD-based systems (including Mac OS X) and Linux. Here, we note the command line option for both BSD-based systems and Linux.

In BSD-based operating systems such as FreeBSD, NetBSD, and Mac OS X, you can use the “-D” option to set “Don't Fragment bit” like the following command.

# ping -D -s <size> <target-host-name>

In Linux operating systems, you can use the “-M do” option to set “Don't Fragment bit” like the following command.

# ping -M do -s <size> <target-host-name>

ZFS on FreeBSD

Please refer to ZFS on FreeBSD.

Use inbound interface's IP address for ICMP errors on Linux

Linux operating systems return ICMP errors with outbound interface's IP address by default. When we use Linux as a router and we want to resolve the path by traceroute etc., this mechanism sometimes bothers us because the results of traceroute may not the actual path for asymmetric paths. To use inbound interface's IP address for ICMP errors on Linux, execute the following command:

# sysctl -w net.ipv4.icmp_errors_use_inbound_ifaddr=1

If you want to keep this setting after next boot, add the following line to /etc/sysctl.conf on your Linux:


Other tips





iPhone memo

AdHoc distribution

  1. "new file"
  2. "resources"
  3. "iPhoneOS-Code Siigning"
  4. "Entitlements"
  5. "dist.plist"
  6. Unckeck "get-task-allow"
  7. Configuration::Code Signing Entitlements --> "get-task-allow"

N.B., Ckeck "get-task-allow" for development (i.e., when you plug your iPhone in directly and install your app through Xcode).

Clustering memo


OS development

OS開発 [written in Japanese]

Aeons: Yet Another Programming Language

Under development. Current version of this software is available at aeons-current.tar.gz, although this version is NOT ready to launch, i.e., UNDER DEVELOPMENT.

Create a programming language in C (C言語で作るプログラミング言語) [written in Japanese]