On 5 October 2012 00:06, Manjusha Joshi <manjusha.jo...@gmail.com> wrote: > 1. There will be talk by Hitesh Wadekar on Openstack. >
[ Query on VLAN ] On the query of VLAN by Hitesh towards the end of the session, I promised to reply to the mailing-list. Here it is. 802.1q and 802.1d permit only 12-bit fields as a standard, hence the strict implementation of VLAN is restrictive to 2^12 bits (4095 unique ids) Strictly speaking this is VLAN ID [4-bit] + VLAN Unique ID [12-bit] which would keep it 16-bit wide. linux/drivers/net/macvlan.c has the 802.1q/d standard that has limitations to 12-bits. linux/drivers/net/vxlan.c has the 24-bit Cisco/Broadcom support tag extension - effectively 2^24 - that's exactly (4096)^2 This is on the linux 3.5.5 and the 3.6 tree and the linux-next tree. The vxlan.c is still version 0.1 (early), but is intended for OpenStack and Cloud Servers. [ SetUID bit ] Behavior on linux-kernel 3.2.x with $ chmod a+s somefolder $ ls -ltr somefolder shows all files inside somefolder with their original rights and *owners* on ext4. This is on Debian Wheezy. Although the setUID bit is still used, it is not recommended if you want to have any sense of security on a system. Hope this helps, Beta _______________________________________ Pune GNU/Linux Users Group Mailing List
