Broadcast Packet [7:60738]
I have a small network where users have been complaining of slowness. I decided to run sniffer and was really confused about a machine running on ip address 10.0.3.10 sending a packet to a non-existing ip address which is 10.0.3.127. I understand that broadcast will be sent to all the hosts in the network only to existing ip addresses, but don't understand why the broadcast is going to 10.0.3.127. It doesn't effect the machine, but ofcourse its taking the bandwidth on the ethernet wire.Thanks, ___ Join Excite! - http://www.excite.com The most personalized portal on the Web! Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=60738t=60738 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Broadcast Packet [7:60738]
Well first of all, how is the machine's networking configured? If your network is supposed to have a /24 netmask (255.255.255.0) but you set it to /25 (255.255.255.128) on that one machine, that would explain why that machine thinks 10.0.3.127 is the correct broadcast address. What netmask does that machine have? James Willard [EMAIL PROTECTED] -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Azhar Teza Sent: Thursday, January 09, 2003 3:12 PM To: [EMAIL PROTECTED] Subject: Broadcast Packet [7:60738] I have a small network where users have been complaining of slowness. I decided to run sniffer and was really confused about a machine running on ip address 10.0.3.10 sending a packet to a non-existing ip address which is 10.0.3.127. I understand that broadcast will be sent to all the hosts in the network only to existing ip addresses, but don't understand why the broadcast is going to 10.0.3.127. It doesn't effect the machine, but ofcourse its taking the bandwidth on the ethernet wire.Thanks, ___ Join Excite! - http://www.excite.com The most personalized portal on the Web! Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=60740t=60738 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Broadcast Packet [7:60738]
Thanks James ! the machine has 24 bit mask.--- On Thu 01/09, James Willard lt; [EMAIL PROTECTED] gt; wrote: From: James Willard [mailto: [EMAIL PROTECTED]]To: [EMAIL PROTECTED], [EMAIL PROTECTED]: Thu, 9 Jan 2003 15:28:04 -0500Subject: RE: Broadcast Packet [7:60738]Well first of all, how is the machine's networking configured? If yournetwork is supposed to have a /24 netmask (255.255.255.0) but you set itto /25 (255.255.255.128) on that one machine, that would explain whythat machine thinks 10.0.3.127 is the correct broadcast address. Whatnetmask does that machine have?James [EMAIL PROTECTED] Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf OfAzhar TezaSent: Thursday, January 09, 2003 3:12 PMTo: [EMAIL PROTECTED]: Broadcast Packet [7:60738]I have a small network where users have been complaining of slowness. Idecided to run sniffer and was really confused about a machine runningon ip address 10.0.3.10 sending a packet to a non-existing ip addresswhich is 10.0.3.127. I understand that broadcast will be sent to allthe hosts in the network only to existing ip addresses, but don'tunderstand why the broadcast is going to 10.0.3.127. It doesn't effectthe machine, butofcourse its taking the bandwidth on the ethernet wire. Thanks,___Join Excite! - http://www.excite.comThe most personalized portal on the Web!Message Posted at:http://www.groupstudy.com/form/read.php?f=7amp;i=60738amp;t=60738--FAQ, list archives, and subscription info:http://www.groupstudy.com/list/cisco.htmlReport misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ Join Excite! - http://www.excite.com The most personalized portal on the Web! Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=60742t=60738 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Broadcast Packet [7:60738]
Azhar Teza wrote: Thanks James ! the machine has 24 bit mask. Well then it must be consistently flipping a bit, which would be awfully strange. I guess this could be caused by a hardware or software problem, though most likely it's a misconfiguration. How often does it do this and what is it actually sending? Most analyzers will let you save a packet as text. You could copy and paste it into a message to us so we could take a better look. These packets probably aren't really using much bandwidth unless the device sends them very frequently and they are big packets. Every NIC must process the broadcast and pass it up to IP to determine that it can be trashed, so if it happens a lot, it could be related to the complaint about the network being slow. If it doesn't happen a lot, though, then it's probably not related to the complaint. Priscilla --- On Thu 01/09, James Willard lt; [EMAIL PROTECTED] gt; wrote: From: James Willard [mailto: [EMAIL PROTECTED]]To: [EMAIL PROTECTED], [EMAIL PROTECTED]: Thu, 9 Jan 2003 15:28:04 -0500Subject: RE: Broadcast Packet [7:60738]Well first of all, how is the machine's networking configured? If yournetwork is supposed to have a /24 netmask (255.255.255.0) but you set itto /25 (255.255.255.128) on that one machine, that would explain whythat machine thinks 10.0.3.127 is the correct broadcast address. Whatnetmask does that machine have?James [EMAIL PROTECTED] Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf OfAzhar TezaSent: Thursday, January 09, 2003 3:12 PMTo: [EMAIL PROTECTED]: Broadcast Packet [7:60738]I have a small network where users have been complaining of slowness. Idecided to run sniffer and was really confused about a machine runningon ip address 10.0.3.10 sending a packet to a non-existing ip addresswhich is 10.0.3.127. I understand that broadcast will be sent to allthe hosts in the network only to existing ip addresses, but don'tunderstand why the broadcast is going to 10.0.3.127. It doesn't effectthe machine, butofcourse its taking the bandwidth on the ethernet wire. Thanks,___Join Excite! - http://www.excite.comThe most personalized portal on the Web!Message Posted at:http://www.groupstudy.com/form/read.php?f=7amp;i=60738amp;t=60738--FAQ, list archives, and subscription info:http://www.groupstudy.com/list/cisco.htmlReport misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ Join Excite! - http://www.excite.com The most personalized portal on the Web! Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=60768t=60738 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
