[tcpdump-workers] Tcpdump not showing packets while the TX counter increments.

Guy Harris guy at alum.mit.edu
Tue Nov 11 15:35:44 EST 2014


On Nov 10, 2014, at 2:17 PM, Matthew Schumacher <matt.s at aptalaska.net> wrote:

> I have an unprovisioned ethernet interface showing some TX packets:
> 
> # ifconfig -a eth1
> eth1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>        inet6 fe80::224:e8ff:fe80:9258  prefixlen 64  scopeid 0x20<link>
>        ether 00:24:e8:80:92:58  txqueuelen 1000  (Ethernet)
>        RX packets 1334743  bytes 124150467 (118.3 MiB)
>        RX errors 0  dropped 128753314  overruns 0  frame 0
>        TX packets 81  bytes 6380 (6.2 KiB)
>        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>        device interrupt 48  memory 0xd8000000-d8012800
> 
> But those aren't showing up with:
> 
> # tcpdump -i eth1 -n -e -Q out

What happens with

	tcpdump -i eth1 -n -e -p

i.e., not filtering only for outgoing packets, but also not running in promiscuous mode?  (Just to make sure that the direction filtering is done correctly on Linux.)


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