Tagged Questions

10
votes
2answers
181 views

How long are fragmented TCP fragments kept in the TCP server

Suppose that a given TCP fragment is fragmented into two IP datagrams, and that the first datagram arrives to the TCP server, but the second datagram never arrives. After a certain amount of time the ...
1
vote
2answers
140 views

Is TCP/IP encapsulation MSB or LSB?

Application data sent over TCP experiences multiple encapsulations: The application data is encapsulated within one or many TCP fragments The TCP fragment is encapsulated within one or many IP ...
2
votes
1answer
479 views

Why am I seeing dropped packets in the NIC stats on my Ubuntu server?

I see dropped packets using ifconfig on my eth0 interface: eth0 Link encap:Ethernet HWaddr 00:15:17:0d:03:ca inet addr:10.0.1.2 Bcast:10.0.1.255 Mask:255.255.255.0 UP BROADCAST ...
1
vote
1answer
432 views

pfSense routing between two routers with shared network

I have a network set-up using two pfSense routers arranged like this:- DMZ1 WAN1 WAN2 DMZ2 | | | | | | | | \___ PF1 PF2___/ | ...
-1
votes
3answers
2k views

Can ping servers but cannot connect to them

Sorry in advance if this question is a bit newbi-ish. I downloaded Microsoft Connection Manager and added multiple .rdg files for different servers I need to access. I can browse to only a few of ...
0
votes
0answers
124 views

Why would one server be sending DUP ACK packets to one PC, which is responding with HTTP RST packets?

I'm not a network profressional, so please excuse any wrong language. I was debugging why my DNS traffic was a constant 160Kbps on our corporate network. I opened up a wireshark trace, and I see one ...
4
votes
5answers
340 views

Share one IP address with a simple router

We have just moved into a new office and have been given our 'internet connection' in the following form: One Ethernet cable in the corner of the room An IP address with subnet mask 255.255.255.0 ...
0
votes
0answers
37 views

What happens if a DNS requsted was not found in ther server? [closed]

Hello I am a newbie in networking. After trying and reading Networking and the Internets and the web I have not managed to find the right answer to this question "Why it is required to configure a ...
0
votes
1answer
543 views

How to utilise netstat information

We have an application named "Seamer" installed on 2008R2 machine named "R2DUO" which has IP address set as 192.61.247.37 in host file and 172.26.127.40 is IP address of Ethernet card .We have two ...
-1
votes
6answers
227 views

Local Area Network (LAN) communication protocol

I'm a bit confused, and was wondering if someone can set me straight. Under a Local Area Network (LAN), what is the communication protocol for the data packets under i.e. ethernet CAT5 cable that ...
0
votes
1answer
425 views

Using iptables to redirect according to pattern-matching (--string)

what I want to do is to redirect web traffic in this way: Every request to port 80 that HTTP GETs a given address should be redirected to a particular port (4444). Every other request goes to port ...
1
vote
2answers
370 views

Several load-balancing servers listening on single IP/port?

Let's say I have a fully working, load-balanced application server environment. All servers have to fail-over gracefully. It's relatively easy to do with the application servers, but how can I ...
-1
votes
1answer
115 views

Congestion Control in TCP [closed]

Why is the threshold set to one half of the current congestion window size when the timer expires at the sender?
1
vote
2answers
124 views

why there is a large difference during the 1st and 2nd packet and then a very small difference between the 2nd and 3rd packet in the TCP handshake?

Why there is a big difference in the time elapsed between the SYN and SYN-ACK and then a much lesser difference between the time elapsed from SYN-ACK and the last ACK during the TCP 3-way Handshake?
1
vote
1answer
240 views

ICMP destination unreachable

I am working on an arch linux machine with ethernet interface eth1. I have created interface eth1:0 using ifconfig and given it a dummy hw address (00:01:02:03:04:05). When I send a UDP packet to a ...
2
votes
1answer
80 views

Testing my Load Balancer

To test my Load Balancer I would need to create several TCP/IP connections (from one host). Which tool can be used to create this sessions with different source-ip addresses? (no worries, only in my ...
2
votes
2answers
636 views

When does a browser send HTTP payload separately from the HTTP request?

Under what circumstances would you expect a web browser split an HTTP request into two IP packets, even if the sum of the packet sizes is still less than the maximum segment size? I would assume that ...
0
votes
3answers
133 views

TCP/IP- what is it exactly? [closed]

I know that this question sounds stupid, but over all these years, I still have difficulty explaining TCP/IP to people. I don't completely get it myself, and even after reading up on it, the ...
1
vote
1answer
298 views

Hardware won't respond to each others ARP requests

I have two pieces of hardware (embedded devices) that I have setup to communicate via TCP over Ethernet in a client/server fashion. The topology of the network is as follows: ----- | S ||=|== Debug ...
0
votes
3answers
175 views

In Linux, how do I send packets of a certain size to an IP?

What commands can you run? (must be via the terminal)
0
votes
1answer
142 views

No transmission via IP

I'm using netstat on Win XP to check protocol transmission details for TCP, IP, and ICMP. There is transmission only in TCP. No transmission in ICMP is understandable since it's for errors and I ...
3
votes
2answers
671 views

Why is iptables not dropping packets?

I have the following rule in our iptables config file /etc/sysconfig/iptables -A INPUT -s 84.23.99.97 -j DROP And when I do iptables --list I get the following Chain INPUT (policy ACCEPT) target ...