Questions tagged [tcp-ip]
The tcp-ip tag has no summary.
62 questions
0
votes
1
answer
83
views
IP address reachable by curl and ping, but not by telnet or urllib3
Yesterday, I came across puzzling behavior in my home network. I was trying from host 192.168.1.A (macOS) to connect to a selenium cluster running on port 4444 on host 192.168.1.B (ubuntu), and kept ...
- 129
0
votes
0
answers
23
views
Computer intermittently unreacheable through wifi access point
I have a problem with reaching linux hosts through my home network, and I'd be glad for someone to point me in the right direction.
I have a main wifi and wired router running DHCP. All IP addresses ...
- 361
1
vote
0
answers
35
views
LIsten on a port, check another port, if no response run a script, then tunnel connection to that port?
So, I want to use an SSH tunnel proxy occasionally. But I don't want to fire it up manually every time. And this is a laptop so if I just start the SSH tunnel at startup it might die of an occasional ...
- 538
0
votes
1
answer
110
views
tcpdump doesn't appear to call any libpcap's exported function
Digging into tcpdump implementation, I can see that it actually loads the libpcap.so dynamic library in userspace.
However, by use of strace, I can't see any occurrence of calls to any function ...
- 385
1
vote
0
answers
485
views
TCP/IP client-server slow communication
I made some network application.
It is a client-server solution using the TCP/IP protocol.
Clients connect to the server.
They make several connections every second.
Communication consists of units of ...
- 101
1
vote
0
answers
301
views
Linux TCP/IP kernel stack and VFS interaction
I'm reading the Linux kernel implementation of the TCP/IP stack. Everything was ok till I encounter this figure
while reading TCP/IP architecture, design and implementation in Linux
As you may see ...
- 21
0
votes
1
answer
376
views
Reachability of IP address of virtual machine
I have a virtual machine (Linux) installed in my PC (Windows) and I was wondering the reachability of the IP address assigned to the virtual machine.
According to ipconfig on Windows and ifconfig on ...
- 27
0
votes
0
answers
194
views
How to check whether my network connection supports HTTP2, gRPC or WebSocket?
My ISP/AS/NAT is problematic since I think it blocks some transfer-layer protocols.
I want to check whether my connection to my domain behind a CDN (e.g. cloudflare) supports HTTP/2, gRPC, QUIC or ...
- 1
0
votes
1
answer
294
views
TCP communication between client and server after server IP has been deleted
I created a tcp server listening at [IP1:PORT1] and connect to it via a client using [IP2]. On both the client and server, SO_KEEPALIVE and TCP_USER_TIMEOUT are enabled with below config values.
...
- 185
0
votes
1
answer
1k
views
Why eth0 can't access to loopback interface when using curl 127.0.0.1 --interface eth0
Here is how to reproduce this problem:
Start a listen service on port 80: nc -l 80 -k
Access this service using curl: curl 127.0.0.1 --interface eth0
Capture the packet using tcpdump both on eth0 and ...
2
votes
4
answers
2k
views
Can a NAT router run out of ports?
The highest TCP port number is 65535. If a router doing NAT uses an ephemeral port for each connection made to the internet on behalf of the hosts on the internal network, does this mean that it is ...
- 3,278
1
vote
1
answer
545
views
-Y and read {src,dst} port and tshark
tshark get data from interface or pcap files. When it read data from interface, user has to write filter with -f (accortding to pcap-filter(7)) and when read from file user has to write filter with -Y ...
- 11.3k
1
vote
2
answers
275
views
Initiating Bulk TCP connections
Our company has 2 proxy servers that are running a vendor proprietary OS that is built on top of FreeBSD 11.2, we are having incidents on our business peak hours where proxy server stops accepting new ...
- 89
0
votes
2
answers
921
views
My first Configuration DNS doesn't work or respond on centos
for studying purposes about TCP/IP, we should run a DNS server, i did the advised configuration, the server is runing without any erros, but when i request the server for the configured domain name ...
- 15
0
votes
0
answers
230
views
Why ping don't response for long time even -W is specified?
I'm just confused with ping. As per my understanding, when I ping some IP address, it sends an ICMP message to the destination, and if there is no response, it get either "request timeout" ...
- 163