Hi, For key chain which used for RIP/IGRP/EIGRP authentication purpose, if the time range of multiple key overlaps, which one actually takes effort? The first one or all of them. According to what CCO says: http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/np1_c /1cprt1/1ceigrp.htm There is a example in the bottom, figure 28, I don't understand why Router A send with key 2, and B send key 1, also it says A and B accept key 1 and 2, but I never made it work in my home lab. Any advice is appreciated, Jerry _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=1946&t=1946 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]