diff options
-rw-r--r-- | NEWS | 4 | ||||
-rw-r--r-- | pxelinux.asm | 6 |
2 files changed, 9 insertions, 1 deletions
@@ -12,6 +12,10 @@ Changes in 2.06: actually process comments in the header and odd alignments of the various parameters, as well as "plain" (not raw) files and PBM and PGM files. + * PXELINUX: Lower the default MTU to 1472 in order to deal + with systems with slightly nonstandard MTUs, and PXE + stacks which don't defragment correctly. Unfortunately this + is very hard to test dynamically. Changes in 2.05: * PXELINUX: Add a default query based on the hardware address diff --git a/pxelinux.asm b/pxelinux.asm index 337dcc6d..3becef28 100644 --- a/pxelinux.asm +++ b/pxelinux.asm @@ -42,7 +42,11 @@ TFTP_PORT equ htons(69) ; Default TFTP port PKT_RETRY equ 6 ; Packet transmit retry count PKT_TIMEOUT equ 12 ; Initial timeout, timer ticks @ 55 ms ; Desired TFTP block size -TFTP_LARGEBLK equ (1500-20-8-4) ; MTU 1500 - IP hdr - UDP hdr - TFTP hdr +; For Ethernet MTU is normally 1500. Unfortunately there seems to +; be a fair number of networks with "substandard" MTUs which break. +; The code assumes TFTP_LARGEBLK <= 2K. +TFTP_MTU equ 1472 +TFTP_LARGEBLK equ (TFTP_MTU-20-8-4) ; MTU - IP hdr - UDP hdr - TFTP hdr ; Standard TFTP block size TFTP_BLOCKSIZE_LG2 equ 9 ; log2(bytes/block) TFTP_BLOCKSIZE equ (1 << TFTP_BLOCKSIZE_LG2) |