# Interface DOWN and UP in promiscuous mode



## vagifzeynalov (Jun 13, 2011)

Hi All,

I just changed my dedicated server to a new one and there I found some annoying problem - when I run *tcpdump* my network connection goes DOWN and UP for a few seconds. Perhaps someone knows how to fix it?

I use:

```
# uname -a
FreeBSD xxxxxxx.com 8.2-RELEASE-p2 FreeBSD 8.2-RELEASE-p2 #0: Fri Jun 10 22:24:52 UTC 2011     admin@xxxxxx.com:/usr/obj/usr/src/sys/kernel  amd64
```

My kernel was rebuilt based on a GENERIC configuration (but the same problem was with the distributed kernel too):

```
# cat kernel

include GENERIC

ident kernel

# ================ Enable pf & altq ==============
# PF
device pf
device pflog
device pfsync

# ALTQ
options ALTQ
options ALTQ_CBQ
options ALTQ_RED
options ALTQ_RIO
options ALTQ_HFSC
options ALTQ_CDNR
options ALTQ_PRIQ

# ================== Enable NETGRAPH =======================
options NETGRAPH
options NETGRAPH_ASYNC
options NETGRAPH_BPF
options NETGRAPH_BRIDGE
options NETGRAPH_CISCO
options NETGRAPH_ECHO
options NETGRAPH_ETHER
options NETGRAPH_FRAME_RELAY
options NETGRAPH_GIF
options NETGRAPH_GIF_DEMUX
options NETGRAPH_HOLE
options NETGRAPH_IFACE
options NETGRAPH_IP_INPUT
options NETGRAPH_KSOCKET
options NETGRAPH_L2TP
options NETGRAPH_LMI

#=== options NETGRAPH_MPPC_COMPRESSION
options NETGRAPH_MPPC_ENCRYPTION
options NETGRAPH_ONE2MANY
options NETGRAPH_PPP
options NETGRAPH_PPTPGRE
options NETGRAPH_RFC1490
options NETGRAPH_SOCKET
options NETGRAPH_TCPMSS
options NETGRAPH_TEE
options NETGRAPH_TTY
options NETGRAPH_UI
options NETGRAPH_VJC
#===================================================
```

After the first run of *tcpdump* I can see the next messages in the *dmesg*:


```
# dmesg
fxp0
:< 5p>rf
x<6p>0o
m<5i>s:
 <l6i>nc
u<o5u>sk
 <6s>t
m<o5d>ea
t<6e>
e<5n>ac
h<6a>nb
l<e5d>
g
ed to DOWN
fxp0: link state changed to UP
fxp0: promiscuous mode disabled
fxp0: link state changed to DOWN
fxp0: link state changed to UP
```
 
Let me know if you want to see some other details.

Thank you.


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