All Questions
9
questions
1
vote
0
answers
45
views
understand ss -to4 output for a jdbc connection
My application connects to a database over JDBC, and performs a lot of sequential inserts. There is only 1 JDBC connection opened by the application. As the performance is not as expected, I started ...
- 11
6
votes
1
answer
13k
views
Capture only TCP SYN-ACK packets with tcpdump
I'm trying to capture only TCP SYN-ACK packets, i.e. with both SYN and ACK bits set with:
tcpdump -vvvni eth0 tcp[tcpflags] == tcp-syn and tcp[tcpflags] == tcp-ack
but it gives such error:
tcpdump: ...
- 244
1
vote
0
answers
4k
views
How to make tcpdump display only source IP, destination IP, ports and timestamps
I am running tcpdump to track traffic on 2 interfaces, one input and one output. The sole purpose is to measure the latency between the time when the input interface receives incoming TCP traffic and ...
- 249
3
votes
0
answers
819
views
Inactive / Unknown TCP connections
I can see the following TCP connections in one of my linux host.
root@odb-us:~# netstat -a | grep ESTAB | grep 10.12
tcp 0 0 odb-us.:2424 10.12.0.77:40000 ESTABLISHED
tcp 0 ...
- 31
0
votes
3
answers
2k
views
Why does TCP sends more than 1 ack per packet?
My source sends packets of 4794 bytes (at least according to the capturing it looks like 1 packet each), however, the destination machine sends 2 acks for every packet sent from source.
I've tried ...
- 187
0
votes
0
answers
792
views
NAT doesn't allow TCP ACK for sent TCP SYN
We are using TCP Simultaneous Open for connecting TCP socket. Lets call one SideA and other SideB.
From the wireshark log I see that first two SYN sent from SideB is blocked by SideA NAT. Then SideA ...
- 101
2
votes
1
answer
1k
views
How to split pcap files maintaining tcp sessions
I have a pcap file which contains tcp traces.
I was wondering if there's a way to split these traces in order to maintain tcp flows, but also filtering the traffic on a src ip basis.
For example, if ...
- 121
3
votes
1
answer
4k
views
have tcpdump show the 'conversation' as i would get from wireshark?
Is it possible to get the same output i would get from:
tcpdump port 80 -w log.pcap
wireshark log.pcap
in wireshark Analyze > Follow TCP Stream and then in the bottom drop down Entire ...
- 31
1
vote
1
answer
849
views
What does this tcpdump printout mean?
I'm not very experience with networking, so on my free time, I usually try and learn some more things about the internet and how it works. While at school, I came across tcpdump and wanted to give it ...
