On Wed, Aug 29, 2012 at 1:55 PM, STARNES, CURTIS <Curtis.Starnes@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