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Questions tagged [packet]

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How can I maximize UDP Packet Size?

I am a gamer. I play UDP-based games. I want to increase the packet size. I know the UDP packet size is 1024 but i want to increase this packet size even more. I want to increase the performance I get on the UDP-based games. I'm new to this so…
Tuna Enis
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How to find the linux user that sent the packet

Our server is compromised and we would like to know which accounts sent the malicious queries from our server. I used tcpdump to get this : our.host.net.48194 > box5596.bluehost.com.http: Flags [P.], cksum 0x0bf8 (incorrect -> 0x5061), seq 0:741,…
SmootQ
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How to limit packets per unit time on a particular interface (for vms)

I am using kvm and virtuozzo virtualization on my servers and each having 10 vms. I have to restrict DDOS attack from my VMS (i.e prevent VM from doing DDOS attack), I search on net and found that I can restrict number of packets using iptables…
Ganesh Gosavi
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Forwarded Packets are received by namespace's veth0 but not received by application

I use libtins (It uses Pcap) to capture link layer packets and forward to a network namespace where the actual application runs on. Client(Browser) -> Server -> Pcap -> Pcap Send -> br0 (Bridge) -> Namespace -> Application Now, I see that the…
sqlbie
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What's the expected behavior in TCP when hosts don't specify the MSS during handshake?

Let's suppose there are two hosts A and B and they are going to communicate over TCP. I am curious about the behavior of TCP related to MSS. Wikipedia says default value of MSS is 536. But, RFC-793 states - when MSS option is not specified any…
InvisibleWolf
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Does tcpdump guarantee packet integrity?

In normal use of tcpdump without any parameter, does it guarantee? tcpdump -i eth0 -w file.pcap In using tcpdump rotating by time with -G parameter, does it guarantee? tcpdump -i eth0 -w file.pcap -G 60 In both case, throughput is apprx 1Gbit
hakansel05
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Is there is any tool/way to find out why packet is getting dropped due to an arp cache full?

My developer hypothesis is packet is getting dropped at arp layer. We increased the default value of neigh.default.gc_thresh3 1024 --> 2048 and now everything looks good. But I want to understand is there is a way to figure it out arp packet loss.I…
Prashant Lakhera
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HTML code trying to load PDF file from Site using ssl with self signed certificate

My employer has a web application that loads a pdf file onto the client browser by having a code that does the ff: embed src="https://somepage.somesite.com/folderpath/somefile.pdf" width="100%" height="100%" Things to note: The site being accessed…
rjmendaxx
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Can a router be connected to a both a subnet and a subnet inside that subnet?

Can a router be connected to both a subnet 1 and a subnet 1.1 which is a subnet inside of subnet 1? For example, can a router be connected and sent packets to subnet 223.1.17.128/25 and 223.1.17.192/28? Thanks.
Caleb Bolton
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In iptables, if a packet is ACCEPTed in one table, does it bypass the next table?

If a packet is ACCEPTed from, say, the INPUT chain of the mangle table, will it bypass the INPUT chain of the filter table and go straight to the local process? Or will the INPUT chain of the filter table process the packet again, and has a chance…
dayuloli
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Force jumbo packet fragmentation

We are in a cluster environment. We have compute nodes with jumbo packets enabled and a MTU of 9000. We are running into some issues in tracebacks to an address outside of our lan, where jumbo packets are being dropped due a firewall with a standard…
Martin Forde
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How to mark packets depending on hostname?

We can mark packets on the basis of IP addresses in the following way - iptables -A FORWARD -t mangle -s 123.2.3.4 -j MARK --set-mark 1 How to mark packets depending on the hostname? I tried this - iptables -A FORWARD -t mangle -s google.co.in -j…
cold_coder
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High Traffic from Content Delivery Networks

I am having trouble on our school network recently. When browsing the internet users will often get an error from the browser saying "No Internet DNS_PROBE_FINISHED_NXDOMAIN" but when they refresh the page will load. I at first suspected our dns…
Joel Page
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Drop packet containing the selected string

How can I drop all packets on windows server that are containing a specific string? The string is: TSource Windows Firewall doesn't seem to have this kind of option.
krisk
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Force Windows to send packets as soon as they arrive the nic

I have a network application running on Windows Server 2008 R2, that must send small packets in a very short time interval, each microsecond matters. My problem is that windows accumulates the packets and sends them in a big TCP packet, but I want…
Yekoor
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