[155897] in North American Network Operators' Group
Re: Level 3 BGP Advertisements
daemon@ATHENA.MIT.EDU (Matt Addison)
Wed Aug 29 19:08:47 2012
From: Matt Addison <matt.addison@lists.evilgeni.us>
In-Reply-To: <CADVasu730tGc8QB_qkoiONeMUvSXQDz4ZBOpQqn6gYWQOuWvRw@mail.gmail.com>
Date: Wed, 29 Aug 2012 19:08:13 -0400
To: james machado <hvgeekwtrvl@gmail.com>
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Sent from my mobile device, so please excuse any horrible misspellings.
On Aug 29, 2012, at 18:30, james machado <hvgeekwtrvl@gmail.com> wrote:
> 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
MSKB 281579 affects XP home and below. Good times anytime someone adds
a .0 or .255 into an IP pool.
