Sent from my mobile device, so please excuse any horrible misspellings. On Aug 29, 2012, at 18:30, james machado <hvgeekwt...@gmail.com> wrote:
> 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 MSKB 281579 affects XP home and below. Good times anytime someone adds a .0 or .255 into an IP pool.
