Home page logo

nanog logo nanog mailing list archives

Re: Level 3 BGP Advertisements
From: james machado <hvgeekwtrvl () gmail com>
Date: Wed, 29 Aug 2012 15:30:22 -0700

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, 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


  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]