Bug ID: 6746613 ip's DL_NOTE_SDU_SIZE logic mishandles ill_max_frag < ill_max

Bug ID	6746613
Synopsis	ip's DL_NOTE_SDU_SIZE logic mishandles ill_max_frag < ill_max_mtu
State	10-Fix Delivered (Fix available in build)
Category:Subcategory	kernel:tcp-ip
Keywords
Responsible Engineer	Peter Memishian
Reported Against
Duplicate Of
Introduced In	solaris_10
Commit to Fix	snv_107
Fixed In	snv_107
Release Fixed	solaris_nevada(snv_107)
Related Bugs	6783149 , 4855563 , 5086201
Submit Date	10-September-2008
Last Update Date	28-January-2009
Description	During Clearview IPMP development, I happened upon an edge case in the current DL_NOTE_SDU_SIZE handling in ip: if a user has lowered ill_max_mtu via SIOCSLIFLNKINFO, then a subsequent DL_NOTE_SDU_SIZE only affects ill_max_frag and leaves ill_max_mtu untouched. This is incorrect if the new value of ill_max_frag rendered ill_max_mtu unusable. For instance, if the original MTU was 1500, and a SIOCSLIFLNKINFO lowered it to 1496, but then a subsequent DL_NOTE_SDU_SIZE lowers it to 1200, then the MTU value needs to be lowered to 1200 as well, regardless of the user's desire to use 1496.
Work Around	N/A
Comments	This issue appears to have been introduced with PSARC/2004/511; setting "Introduced in Release" and "Introduced in Build" accordingly.

OpenSolaris