Remapping file names with TFTP-HPA for buggy PXE clients

Some PXE clients send extraneous garbage characters in TFTP requests for files, e.g. “RRQ from … filename pxelinux.biny#012;o#036”instead of just “pxelinux.bin”. This is logged in the syslog. To work around this we can use a feature of tftp-hpa to remap file names, based on a rewrite regex: /etc/default/tftp-hpa: TFTP_OPTIONS=”–secure –verbose -v -m /etc/” /etc/ r … Continue reading Remapping file names with TFTP-HPA for buggy PXE clients

Radicale IMAP Auth on Debian 9 (Stretch)

Radicale 2.1 CalDAV may fail with the following error messages logged: radicale.log: [SSL: SSLV3_ALERT_HANDSHAKE_FAILURE] sslv3 alert handshake failure (_ssl.c:720) syslog: … rip=, lip=, TLS handshaking: SSL_accept() failed …… imap-login: Disconnected: Inactivity (no auth attempts in 180 secs): user=<>, rip=, lip=, TLS handshaking This looks like an incompatibility between OpenSSL and Python urllib regarding SSL connections. … Continue reading Radicale IMAP Auth on Debian 9 (Stretch)

PXE Booting Guide

Configure DHCP ServerConfiguration below is for isc-dhcp-server on Linux: # For hardware LAN Boot ROMs:option tftp-server-address;filename “pxelinux.0”;# For HyperV Guests:# option 60 = client identifieroption dhcp-client-identifier “PXEClient”;# option 66 = TFTP server nameoption tftp-server-name “”;# option 67 = Bootfile nameoption bootfile-name “pxelinux.0”; 2. Configure TFTP ServerOn Linux, tftp-hpa is recommended, with a directory structure … Continue reading PXE Booting Guide