On Wed, Aug 29, 2012 at 1:55 PM, STARNES, CURTIS <curtis.star...@granburyisd.org> wrote: > Sorry for the top post... > > Not necessarily a Level 3 problem but; > > We are announcing our /19 network as one block via BGP through AT&T, not > broken up into smaller announcements. > Earlier in the year I started receiving complaints that some of our client > systems were having problems connecting to different web sites. > After much troubleshooting I noticed that in every instance the xlate in our > Cisco ASA for the client's IP last octet was either a 0 or 255. > Since I am announcing our network as a /19, the subnet mask is 255.255.224.0, > that would make our network address x.x.192.0 and the broadcast x.x.223.255. > So somewhere the /24 boundary addresses were being dropped. > > Just curious if anyone else has seen this before.
some OS's by M and others as well as some devices have IP stacks which will not send or receive unicast packets ending in 0 or 255. have had casses where someone was doing subnets that included those in the DCHP scopes and the computers that received these addresses were black holes. james
