tcpdump on openwrt does not output anything
0
I installed openwrt on my router and I'm looking for a way to use tcpdump properly. My internal IP address is 192.168.1.10.
Running tcpdump -i any -l -vvv src 192.168.1.10 and dst not 192.168.1.1 does not output anything and tcpdump -i any src 192.168.1.10 only (many lines of the same kind of logs):
15:17:47.078689 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60065, win 65535, length 0
15:17:47.078744 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60065, win 65535, length 0
15:17:47.079840 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60225, win 65535, length 0
How is it possible? The same happens if any is replaced by any other interface.
networking openwrt tcpdump
asked Jan 5 at 15:30
xuhozixxuhozix
1
|
show 1 more comment
0
I installed openwrt on my router and I'm looking for a way to use tcpdump properly. My internal IP address is 192.168.1.10.
Running tcpdump -i any -l -vvv src 192.168.1.10 and dst not 192.168.1.1 does not output anything and tcpdump -i any src 192.168.1.10 only (many lines of the same kind of logs):
15:17:47.078689 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60065, win 65535, length 0
15:17:47.078744 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60065, win 65535, length 0
15:17:47.079840 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60225, win 65535, length 0
How is it possible? The same happens if any is replaced by any other interface.
networking openwrt tcpdump
asked Jan 5 at 15:30
xuhozixxuhozix
1
What are you expecting to see? Unless you do something or some background process accesses the Internet, nothing being recorded is the expected outcome.
– Daniel B
Jan 5 at 15:37
I'm running it as I have YouTube videos loading and doing other similar activities
– xuhozix
Jan 5 at 15:46
1
Try throwing in a -n on the command line to disable DNS lookups.
– davidgo
Jan 5 at 21:23
@davidgo it works! But why?
– xuhozix
Jan 5 at 23:56
I've never bothered to check, but perceive that the reverse DNS lookups to provide hostnames rather then IPs can take long enough to cause packets to be ignored by tcpdump. (Also why I commented rather then answered.)
– davidgo
Jan 6 at 0:07
|
show 1 more comment
0
0
0
I installed openwrt on my router and I'm looking for a way to use tcpdump properly. My internal IP address is 192.168.1.10.
Running tcpdump -i any -l -vvv src 192.168.1.10 and dst not 192.168.1.1 does not output anything and tcpdump -i any src 192.168.1.10 only (many lines of the same kind of logs):
15:17:47.078689 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60065, win 65535, length 0
15:17:47.078744 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60065, win 65535, length 0
15:17:47.079840 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60225, win 65535, length 0
How is it possible? The same happens if any is replaced by any other interface.
networking openwrt tcpdump
asked Jan 5 at 15:30
xuhozixxuhozix
1
I installed openwrt on my router and I'm looking for a way to use tcpdump properly. My internal IP address is 192.168.1.10.
Running tcpdump -i any -l -vvv src 192.168.1.10 and dst not 192.168.1.1 does not output anything and tcpdump -i any src 192.168.1.10 only (many lines of the same kind of logs):
15:17:47.078689 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60065, win 65535, length 0
15:17:47.078744 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60065, win 65535, length 0
15:17:47.079840 IP 192.168.1.10.43670 > dsldevice.lan.ssh: Flags [.], ack 60225, win 65535, length 0
How is it possible? The same happens if any is replaced by any other interface.
networking openwrt tcpdump
networking openwrt tcpdump
asked Jan 5 at 15:30
xuhozixxuhozix
1
asked Jan 5 at 15:30
xuhozixxuhozix
1
asked Jan 5 at 15:30
xuhozixxuhozix
1
asked Jan 5 at 15:30
xuhozixxuhozix
1
asked Jan 5 at 15:30
xuhozixxuhozix
1
1
What are you expecting to see? Unless you do something or some background process accesses the Internet, nothing being recorded is the expected outcome.
– Daniel B
Jan 5 at 15:37
I'm running it as I have YouTube videos loading and doing other similar activities
– xuhozix
Jan 5 at 15:46
1
Try throwing in a -n on the command line to disable DNS lookups.
– davidgo
Jan 5 at 21:23
@davidgo it works! But why?
– xuhozix
Jan 5 at 23:56
I've never bothered to check, but perceive that the reverse DNS lookups to provide hostnames rather then IPs can take long enough to cause packets to be ignored by tcpdump. (Also why I commented rather then answered.)
– davidgo
Jan 6 at 0:07
|
show 1 more comment
What are you expecting to see? Unless you do something or some background process accesses the Internet, nothing being recorded is the expected outcome.
– Daniel B
Jan 5 at 15:37
I'm running it as I have YouTube videos loading and doing other similar activities
– xuhozix
Jan 5 at 15:46
1
Try throwing in a -n on the command line to disable DNS lookups.
– davidgo
Jan 5 at 21:23
@davidgo it works! But why?
– xuhozix
Jan 5 at 23:56
I've never bothered to check, but perceive that the reverse DNS lookups to provide hostnames rather then IPs can take long enough to cause packets to be ignored by tcpdump. (Also why I commented rather then answered.)
– davidgo
Jan 6 at 0:07
What are you expecting to see? Unless you do something or some background process accesses the Internet, nothing being recorded is the expected outcome.
– Daniel B
Jan 5 at 15:37
What are you expecting to see? Unless you do something or some background process accesses the Internet, nothing being recorded is the expected outcome.
– Daniel B
Jan 5 at 15:37
I'm running it as I have YouTube videos loading and doing other similar activities
– xuhozix
Jan 5 at 15:46
I'm running it as I have YouTube videos loading and doing other similar activities
– xuhozix
Jan 5 at 15:46
1
1
Try throwing in a -n on the command line to disable DNS lookups.
– davidgo
Jan 5 at 21:23
Try throwing in a -n on the command line to disable DNS lookups.
– davidgo
Jan 5 at 21:23
@davidgo it works! But why?
– xuhozix
Jan 5 at 23:56
@davidgo it works! But why?
– xuhozix
Jan 5 at 23:56
I've never bothered to check, but perceive that the reverse DNS lookups to provide hostnames rather then IPs can take long enough to cause packets to be ignored by tcpdump. (Also why I commented rather then answered.)
– davidgo
Jan 6 at 0:07
I've never bothered to check, but perceive that the reverse DNS lookups to provide hostnames rather then IPs can take long enough to cause packets to be ignored by tcpdump. (Also why I commented rather then answered.)
– davidgo
Jan 6 at 0:07
|
show 1 more comment
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What are you expecting to see? Unless you do something or some background process accesses the Internet, nothing being recorded is the expected outcome.
– Daniel B
Jan 5 at 15:37
I'm running it as I have YouTube videos loading and doing other similar activities
– xuhozix
Jan 5 at 15:46
1
Try throwing in a -n on the command line to disable DNS lookups.
– davidgo
Jan 5 at 21:23
@davidgo it works! But why?
– xuhozix
Jan 5 at 23:56
I've never bothered to check, but perceive that the reverse DNS lookups to provide hostnames rather then IPs can take long enough to cause packets to be ignored by tcpdump. (Also why I commented rather then answered.)
– davidgo
Jan 6 at 0:07