Date: Wed, 07 Jun 2006 14:09:16 -0500 From: Paul Schmehl <pauls@utdallas.edu> To: FreeBSD Questions <freebsd-questions@freebsd.org> Subject: Tcpdump dropping packets Message-ID: <4487245C.6070807@utdallas.edu>
next in thread | raw e-mail | index | archive | help
This is a cryptographically signed message in MIME format. --------------ms050606030506080909070403 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit I'm fiddling around with ntop, but, after an initial packet capture, it doesn't capture any more traffic. It claims that libpcap is dropping all the packets. If I run tcpdump like this: tcpdump -i <interface> I get this: 15 packets captured 51104 packets received by filter 50288 packets dropped by kernel If I run tcpdump like this: tcpdump -i <interface> -w filename I get this: 65235 packets captured 65489 packets received by filter 0 packets dropped by kernel Is there a sysctl tweak that can at least reduce the packet loss? Is there a setting in ntop that I'm missing? If I send tcpdump to a file, can ntop read the file continuously? Or will it only read it one time? -- Paul Schmehl (pauls@utdallas.edu) Adjunct Information Security Officer The University of Texas at Dallas http://www.utdallas.edu/ir/security/ --------------ms050606030506080909070403 Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIOyjCC A9gwggNBoAMCAQICEEHsHz2nFAeWxPbVDN3RD2UwDQYJKoZIhvcNAQEFBQAwgcExCzAJBgNV BAYTAlVTMRcwFQYDVQQKEw5WZXJpU2lnbiwgSW5jLjE8MDoGA1UECxMzQ2xhc3MgMiBQdWJs aWMgUHJpbWFyeSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eSAtIEcyMTowOAYDVQQLEzEoYykg MTk5OCBWZXJpU2lnbiwgSW5jLiAtIEZvciBhdXRob3JpemVkIHVzZSBvbmx5MR8wHQYDVQQL ExZWZXJpU2lnbiBUcnVzdCBOZXR3b3JrMB4XDTk5MDMzMTAwMDAwMFoXDTA5MDMzMDIzNTk1 OVowgeoxJzAlBgNVBAoTHlRoZSBVbml2ZXJzaXR5IG9mIFRleGFzIFN5c3RlbTEfMB0GA1UE CxMWVmVyaVNpZ24gVHJ1c3QgTmV0d29yazE7MDkGA1UECxMyVGVybXMgb2YgdXNlIGF0IGh0 dHBzOi8vd3d3LnZlcmlzaWduLmNvbS9ycGEgKGMpOTkxMjAwBgNVBAsTKUNsYXNzIDIgQ0Eg LSBPblNpdGUgSW5kaXZpZHVhbCBTdWJzY3JpYmVyMS0wKwYDVQQDEyRUaGUgVW5pdmVyc2l0 eSBvZiBUZXhhcyBhdCBEYWxsYXMgQ0EwgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBAL/q 74frHgrBAPkiEcHRwczbetq+NtJwYDBg5RngUy819MmoKQXW3j2d8waaZH2+0YdUeJv/onjx +4erw/yHTMJJQQ3hwNKl1/x+/0JRTnTzAdVoc6VdBDH45iklY6gjmkRqgYsPsDnx79tGWMO6 uM9L83rBokmVgyNDupsajzKFAgMBAAGjgaUwgaIwKQYDVR0RBCIwIKQeMBwxGjAYBgNVBAMT EVByaXZhdGVMYWJlbDEtMTQwMBEGCWCGSAGG+EIBAQQEAwIBBjBEBgNVHSAEPTA7MDkGC2CG SAGG+EUBBwEBMCowKAYIKwYBBQUHAgEWHGh0dHBzOi8vd3d3LnZlcmlzaWduLmNvbS9SUEEw DwYDVR0TBAgwBgEB/wIBADALBgNVHQ8EBAMCAQYwDQYJKoZIhvcNAQEFBQADgYEAUwm13LK2 idEgUIPJOHncyAiySb+4U4Nvisyy5Hp8/KPoD19hXl+XBJUSWtKVASLxvO3xVLZUplQYoZ1U vAZpBMcCITeigjmIp6ygn+iDGV2SSDkaWYIkIEO8hpUS3IN04ebjE75qpIcAMTEjByWbr7os UZEOWaajF4jStM5UFxwwggVzMIIE3KADAgECAhAhQ2wPNrJWs2gXrRmRcAj6MA0GCSqGSIb3 DQEBBAUAMIHqMScwJQYDVQQKEx5UaGUgVW5pdmVyc2l0eSBvZiBUZXhhcyBTeXN0ZW0xHzAd BgNVBAsTFlZlcmlTaWduIFRydXN0IE5ldHdvcmsxOzA5BgNVBAsTMlRlcm1zIG9mIHVzZSBh dCBodHRwczovL3d3dy52ZXJpc2lnbi5jb20vcnBhIChjKTk5MTIwMAYDVQQLEylDbGFzcyAy IENBIC0gT25TaXRlIEluZGl2aWR1YWwgU3Vic2NyaWJlcjEtMCsGA1UEAxMkVGhlIFVuaXZl cnNpdHkgb2YgVGV4YXMgYXQgRGFsbGFzIENBMB4XDTA1MDgxMDAwMDAwMFoXDTA2MDgxMDIz NTk1OVowgfQxJzAlBgNVBAoUHlRoZSBVbml2ZXJzaXR5IG9mIFRleGFzIFN5c3RlbTEtMCsG A1UECxQkVGhlIFVuaXZlcnNpdHkgb2YgVGV4YXMgYXQgRGFsbGFzIENBMUYwRAYDVQQLEz13 d3cudmVyaXNpZ24uY29tL3JlcG9zaXRvcnkvQ1BTIEluY29ycC4gYnkgUmVmLixMSUFCLkxU RChjKTk5MRgwFgYDVQQLFA9NYWlsIFN0b3AgLSBVVEQxFTATBgNVBAMTDFBhdWwgU2NobWVo bDEhMB8GCSqGSIb3DQEJARYScGF1bHNAdXRkYWxsYXMuZWR1MIGfMA0GCSqGSIb3DQEBAQUA A4GNADCBiQKBgQDEoeaWOSJTLA4v6OJEuCfJukxz2ljvM2G7CovCFsCYK7FnYSzTjFAk8Vhe +STjF4ehWIMnyGzWHYP6Vude2sWSxsXvUANOsjNKeWZ5rSjFS52u+1JU2IiIiwISnlAmOKC9 eqXGq7iIPz35w3VbpxPeGe6GWK4ZfexTKSQtfPYfSQIDAQABo4ICDDCCAggwCQYDVR0TBAIw ADAdBgNVHREEFjAUgRJwYXVsc0B1dGRhbGxhcy5lZHUwggEkBgNVHSAEggEbMIIBFzCCARMG C2CGSAGG+EUBBwEGMIIBAjArBggrBgEFBQcCARYfaHR0cHM6Ly93d3cudmVyaXNpZ24uY29t L3JwYS1rcjCB0gYIKwYBBQUHAgIwgcUagcJOT1RJQ0U6IFByaXZhdGUga2V5IG1heSBiZSBy ZWNvdmVyZWQgYnkgVmVyaVNpZ24ncyBjdXN0b21lciB3aG8gbWF5IGJlIGFibGUgdG8gZGVj cnlwdCBtZXNzYWdlcyB5b3Ugc2VuZCB0byBjZXJ0aWZpY2F0ZSBob2xkZXIuICBVc2UgaXMg c3ViamVjdCB0byB0ZXJtcyBhdCBodHRwczovL3d3dy52ZXJpc2lnbi5jb20vcnBhLWtyIChj KTk5LjARBglghkgBhvhCAQEEBAMCB4AwdQYDVR0fBG4wbDBqoGigZoZkaHR0cDovL29uc2l0 ZWNybC52ZXJpc2lnbi5jb20vVGhlVW5pdmVyc2l0eW9mVGV4YXNTeXN0ZW1UaGVVbml2ZXJz aXR5b2ZUZXhhc2F0RGFsbGFzQ0EvTGF0ZXN0Q1JMLmNybDALBgNVHQ8EBAMCB4AwHQYDVR0l BBYwFAYIKwYBBQUHAwQGCCsGAQUFBwMCMA0GCSqGSIb3DQEBBAUAA4GBAEHYOgkUsyvG/DYG FAKSJ+IqUY4NVstEHCKHim3Cckq0Chxf+yRQB4tvOrwPTFAHlMgqJKr4yVXEvwJmhAvJtO/V nYex/brnBVky3UI288HXzk7439zbvmmczLZmOhsR3A3TnKHX9vdTmJ7sxWExDszRQntTfoUY cQihaFVOqZ9sMIIFczCCBNygAwIBAgIQPzPhdzYQCWxtZCkhSwOckTANBgkqhkiG9w0BAQQF ADCB6jEnMCUGA1UEChMeVGhlIFVuaXZlcnNpdHkgb2YgVGV4YXMgU3lzdGVtMR8wHQYDVQQL ExZWZXJpU2lnbiBUcnVzdCBOZXR3b3JrMTswOQYDVQQLEzJUZXJtcyBvZiB1c2UgYXQgaHR0 cHM6Ly93d3cudmVyaXNpZ24uY29tL3JwYSAoYyk5OTEyMDAGA1UECxMpQ2xhc3MgMiBDQSAt IE9uU2l0ZSBJbmRpdmlkdWFsIFN1YnNjcmliZXIxLTArBgNVBAMTJFRoZSBVbml2ZXJzaXR5 IG9mIFRleGFzIGF0IERhbGxhcyBDQTAeFw0wNTA4MTAwMDAwMDBaFw0wNjA4MTAyMzU5NTla MIH0MScwJQYDVQQKFB5UaGUgVW5pdmVyc2l0eSBvZiBUZXhhcyBTeXN0ZW0xLTArBgNVBAsU JFRoZSBVbml2ZXJzaXR5IG9mIFRleGFzIGF0IERhbGxhcyBDQTFGMEQGA1UECxM9d3d3LnZl cmlzaWduLmNvbS9yZXBvc2l0b3J5L0NQUyBJbmNvcnAuIGJ5IFJlZi4sTElBQi5MVEQoYyk5 OTEYMBYGA1UECxQPTWFpbCBTdG9wIC0gVVREMRUwEwYDVQQDEwxQYXVsIFNjaG1laGwxITAf BgkqhkiG9w0BCQEWEnBhdWxzQHV0ZGFsbGFzLmVkdTCBnzANBgkqhkiG9w0BAQEFAAOBjQAw gYkCgYEA3kw5bRGnSgWiYrAFsDKH4M+0r3YOazqaJ+NCzHzSYci2dgE2thVNAGe9i4xLBL8I ZX7i5HkR6mTit9/ovF/SUCft+2UapqYEu1sLPKuqEHfA2p8c5mjkJHnUYz2KR+4Z1UtvmTmN NwdaWfWfCzL/stJfR/qpNNqZLaDpBiytj4ECAwEAAaOCAgwwggIIMAkGA1UdEwQCMAAwHQYD VR0RBBYwFIEScGF1bHNAdXRkYWxsYXMuZWR1MIIBJAYDVR0gBIIBGzCCARcwggETBgtghkgB hvhFAQcBBjCCAQIwKwYIKwYBBQUHAgEWH2h0dHBzOi8vd3d3LnZlcmlzaWduLmNvbS9ycGEt a3IwgdIGCCsGAQUFBwICMIHFGoHCTk9USUNFOiBQcml2YXRlIGtleSBtYXkgYmUgcmVjb3Zl cmVkIGJ5IFZlcmlTaWduJ3MgY3VzdG9tZXIgd2hvIG1heSBiZSBhYmxlIHRvIGRlY3J5cHQg bWVzc2FnZXMgeW91IHNlbmQgdG8gY2VydGlmaWNhdGUgaG9sZGVyLiAgVXNlIGlzIHN1Ympl Y3QgdG8gdGVybXMgYXQgaHR0cHM6Ly93d3cudmVyaXNpZ24uY29tL3JwYS1rciAoYyk5OS4w EQYJYIZIAYb4QgEBBAQDAgeAMHUGA1UdHwRuMGwwaqBooGaGZGh0dHA6Ly9vbnNpdGVjcmwu dmVyaXNpZ24uY29tL1RoZVVuaXZlcnNpdHlvZlRleGFzU3lzdGVtVGhlVW5pdmVyc2l0eW9m VGV4YXNhdERhbGxhc0NBL0xhdGVzdENSTC5jcmwwCwYDVR0PBAQDAgUgMB0GA1UdJQQWMBQG CCsGAQUFBwMEBggrBgEFBQcDAjANBgkqhkiG9w0BAQQFAAOBgQArtwI07378ACzBYQlXjg4u 4Ex2FlHoY3C5cWuTkXyzqJyU2ttpgxzzMTjYgqNeHdA3I360rCDSp/LCuNKhLQ9PdU/9LcU3 duD6KJU3cG4UrmfUXecXFdWj2wnp0Pkiq6YoSPQQ946dpq1BvWxE2W8J9f09tuR3Jjfgf1ST +qMgwTGCBIcwggSDAgEBMIH/MIHqMScwJQYDVQQKEx5UaGUgVW5pdmVyc2l0eSBvZiBUZXhh cyBTeXN0ZW0xHzAdBgNVBAsTFlZlcmlTaWduIFRydXN0IE5ldHdvcmsxOzA5BgNVBAsTMlRl cm1zIG9mIHVzZSBhdCBodHRwczovL3d3dy52ZXJpc2lnbi5jb20vcnBhIChjKTk5MTIwMAYD VQQLEylDbGFzcyAyIENBIC0gT25TaXRlIEluZGl2aWR1YWwgU3Vic2NyaWJlcjEtMCsGA1UE AxMkVGhlIFVuaXZlcnNpdHkgb2YgVGV4YXMgYXQgRGFsbGFzIENBAhAhQ2wPNrJWs2gXrRmR cAj6MAkGBSsOAwIaBQCgggLdMBgGCSqGSIb3DQEJAzELBgkqhkiG9w0BBwEwHAYJKoZIhvcN AQkFMQ8XDTA2MDYwNzE5MDkxNlowIwYJKoZIhvcNAQkEMRYEFM+n4DvlOjeumADgEo/rZV2Z b4z8MFIGCSqGSIb3DQEJDzFFMEMwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqG SIb3DQMCAgFAMAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIIBEQYJKwYBBAGCNxAEMYIBAjCB /zCB6jEnMCUGA1UEChMeVGhlIFVuaXZlcnNpdHkgb2YgVGV4YXMgU3lzdGVtMR8wHQYDVQQL ExZWZXJpU2lnbiBUcnVzdCBOZXR3b3JrMTswOQYDVQQLEzJUZXJtcyBvZiB1c2UgYXQgaHR0 cHM6Ly93d3cudmVyaXNpZ24uY29tL3JwYSAoYyk5OTEyMDAGA1UECxMpQ2xhc3MgMiBDQSAt IE9uU2l0ZSBJbmRpdmlkdWFsIFN1YnNjcmliZXIxLTArBgNVBAMTJFRoZSBVbml2ZXJzaXR5 IG9mIFRleGFzIGF0IERhbGxhcyBDQQIQPzPhdzYQCWxtZCkhSwOckTCCARMGCyqGSIb3DQEJ EAILMYIBAqCB/zCB6jEnMCUGA1UEChMeVGhlIFVuaXZlcnNpdHkgb2YgVGV4YXMgU3lzdGVt MR8wHQYDVQQLExZWZXJpU2lnbiBUcnVzdCBOZXR3b3JrMTswOQYDVQQLEzJUZXJtcyBvZiB1 c2UgYXQgaHR0cHM6Ly93d3cudmVyaXNpZ24uY29tL3JwYSAoYyk5OTEyMDAGA1UECxMpQ2xh c3MgMiBDQSAtIE9uU2l0ZSBJbmRpdmlkdWFsIFN1YnNjcmliZXIxLTArBgNVBAMTJFRoZSBV bml2ZXJzaXR5IG9mIFRleGFzIGF0IERhbGxhcyBDQQIQPzPhdzYQCWxtZCkhSwOckTANBgkq hkiG9w0BAQEFAASBgBw8ch2PnCFdCynPTAkGEN98i+dXXoXWQz4qO3HWQOEPIYOtLjxDeZtk elblY+nZPw56tyzGzTGI6bfSuw0HEVMGq+OxRX58ONcuxyojlaGcYAj54b8Z7az4boPUNMpq /4WsMTipQQ1BJ9KlC3Z5KLjVNmTIxQUzX4UegiLTamk5AAAAAAAA --------------ms050606030506080909070403--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4487245C.6070807>