tcpdump: BIOCSETIF: en0: Do not specify an existing file

tcpdump BIOCSETIF en0 Do not specify an existing file

 
When i try to capture aix server network packats from Ethernet interface i got the Do not specify an existing file error message.
Error Message :

bash-4.2# tcpdump -i en0 dst 192.168.2.100
tcpdump: BIOCSETIF: en0: Do not specify an existing file

Problem Identification :

Previously i run iptrace utility for capture the network packets, but it’s still running on background.
That’s why i got the this kind of error.

Solution :
Need to check iptrace utility process status.

bash-4.2# ps -ef | grep -i iptrace

if it is running stop the iptrace process.

bash-4.2# stopsrc -s iptrace
0513-004 The Subsystem or Group, iptrace, is currently inoperative.

Again start the iptrace service and check the service status using.

bash-4.2# startsrc -s iptrace
0513-059 The iptrace Subsystem has been started. Subsystem PID is 9699440.

Try to capture the network packates using tcpdump utility.

bash-4.2# tcpdump -i en0 dst
192.168.2.100 tcpdump: BIOCSETIF: en0: Do not specify an existing file

Then also getting same error message Do not specify an existing file.

Resolve actual Problem:
first we need to find out how many network interface configured on our aix server. 

bash-4.2# tcpdump -D
1.lo0

Above tcpdump output showing only one interface but that is loop back logical network interface .
but we did not get the real network interface from that output. it means some other network packet capture utility using that interface so we have to release that interface.

bash-4.2# iptrace -u
iptrace : unload success!

-u –> Unloads the kernel extension that was loaded by the iptrace daemon at startup.
Successfully unloaded the iptrace utility now we can check how many interfaces are available.

bash-4.2# tcpdump -D
1.en0
2.lo0

Result:
Now we start the network packates using tcpdump command it should work.

bash-4.2# tcpdump -i en0 dst 192.168.2.100
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on en0, link-type 1, capture size 96 bytes

 

Related posts

Leave a Comment