tcpdump

[depts2416]

i have been trying to use tcpdump but when i type a command this is all i get:

root@deptsbox:/home/depts2416# tcpdump
tcpdump: WARNING: eth0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes

how do you change what you are listenng to like instead of eth0 it would be ppp0?

[cheesecake42]

post the output from

ifconfig

[depts2416]

here you go....

eth0      Link encap:Ethernet  HWaddr 00:02:A5:F8:F2:DB
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

lo        Link encap:Local Loopback
          inet addr:*.*.*.*  Mask:*.*.*.*
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:69 errors:0 dropped:0 overruns:0 frame:0
          TX packets:69 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:5312 (5.1 KiB)  TX bytes:5312 (5.1 KiB)

ppp0      Link encap:Point-to-Point Protocol
          inet addr:*.*.*.*  P-t-P:*.*.*.*  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:553 errors:0 dropped:0 overruns:0 frame:0
          TX packets:637 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:312243 (304.9 KiB)  TX bytes:100358 (98.0 KiB)

[rcgreen]

tcpdump -D will list your interfaces. I think it numbers them,
so try tcpdump 3 for ppp0, which is the third in the list.

[anomie]

If you're going to supply the interface number (from tcpdump -D listing), you'll need to give it with the -i option.
e.g. # tcpdump -i 3 (if 3 is the correct interface number)

You can also use the interface name that the -D option reports.